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1.
Anal Chim Acta ; 1314: 342769, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-38876513

RESUMO

Echinococcosis and tuberculosis are two common zoonotic diseases that can cause severe pulmonary infections. Early screening and treatment monitoring are of great significance, especially in areas with limited medical resources. Herein, we designed an operation-friendly and rapid magnetic enrichment-silver acetylene chromogenic immunoassay (Me-Sacia) to monitor the antibody. The main components included secondary antibody-modified magnetic nanoparticles (MNP-Ab2) as capture nanoparticles, specific peptide (EG95 or CFP10)-modified silver nanoparticles (AgNP-PTs) as detection nanoparticles, and alkyne-modified gold nanoflowers as chromogenic nanoparticles. Based on the magnetic separation and plasma luminescence techniques, Me-Sacia could completely replace the colorimetric assay of biological enzymes. It reduced the detection time to approximately 1 h and simplified the labor-intensive and equipment-intensive processes associated with conventional ELISA. Meanwhile, the Me-Sacia showed universality for various blood samples and intuitive observation with the naked eye. Compared to conventional ELISA, Me-Sacia lowered the detection limit by approximately 96.8 %, increased the overall speed by approximately 15 times, and improved sensitivity by approximately 7.2 %, with a 100 % specificity and a coefficient of variation (CV) of less than 15 %.


Assuntos
Equinococose , Tuberculose Pulmonar , Humanos , Animais , Tuberculose Pulmonar/diagnóstico , Equinococose/diagnóstico , Imunoensaio/métodos , Prata/química , Ouro/química , Nanopartículas Metálicas/química , Zoonoses/diagnóstico , Limite de Detecção
2.
Anal Chim Acta ; 1314: 342781, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-38876519

RESUMO

BACKGROUND: Okadaic acid (OA), as a diarrhetic shellfish poisoning, can increase the risk of acute carcinogenic or teratogenic effects for the ingestion of OA contaminated shellfish. At present, much effort has been made to graft immunoassay onto a paper substrate to make paper-based sensors for rapid and simple detection of shellfish toxin. However, the complicated washing steps and low protein fixation efficiency on the paper substrate need to be further addressed. RESULTS: A novel paper-tip immunosensor for detecting OA was developed combined with smartphone and naked eye readout. The trapezoid paper tip was consisted of quantitative and qualitative detection zones. To improve the OA antigen immobilization efficiency on the paper substrate, graphene oxide (GO)-assisted protein immobilization method was introduced. Meanwhile, Au nanoparticles composite probe combined with the lateral flow washing was developed to simplify the washing step. The OA antigen-immobilized zone, as the detection zone Ⅰ, was used for quantitative assay by smartphone imaging. The paper-tip front, as the detection zone Ⅱ, which could qualitatively differentiate OA pollution level within 45 min using the naked eye. The competitive immunoassay on the paper tip exhibited a wide linear range for detecting OA (0.02-50 ng∙mL-1) with low detection limit of 0.02 ng∙mL-1. The recovery of OA in spiked shellfish samples was in the range of 90.3 %-113.%. SIGNIFICANCE: These results demonstrated that the proposed paper-tip immunosensor could provide a simple, low-cost and high-sensitivity test for OA detection without the need for additional large-scale equipment or expertise. We anticipate that this paper-tip immunosensor will be a flexible and versatile tool for on-site detecting the pollution of marine products.


Assuntos
Técnicas Biossensoriais , Ouro , Grafite , Ácido Okadáico , Papel , Smartphone , Grafite/química , Ácido Okadáico/análise , Imunoensaio/métodos , Ouro/química , Nanopartículas Metálicas/química , Proteínas Imobilizadas/química , Limite de Detecção , Animais , Anticorpos Imobilizados/imunologia , Anticorpos Imobilizados/química
3.
Mikrochim Acta ; 191(7): 387, 2024 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869719

RESUMO

A novel construction strategy is introduced for an ultrasensitive dynamic light scattering (DLS) immunosensor targeting alpha fetoprotein (AFP). This approach relies on a self-assembled heptamer fusion protein (A1-C4bpα), incorporating the dual functions of multivalent recognition and crosslinking aggregation amplification due to the presence of seven AFP-specific A1 nanobodies on the A1-C4bpα heptamer. Leveraging antibody-functionalized magnetic nanoparticles for target AFP capture and DLS signal output, the proposed heptamer-assisted DLS immunosensor offers high sensitivity, strong specificity, and ease of operation. Under the optimized conditions, the designed DLS immunosensor demonstrates excellent linear detection of AFP in the concentration range 0.06 ng mL-1 to 512 ng mL-1, with a detection limit of 15 pg mL-1. The selectivity, accuracy, precision, practicability, and reliability of this newly developed method were further validated through an assay of AFP levels in spiked and actual human serum samples. This work introduces a novel approach for constructing ultrasensitive DLS immunosensors, easily extendable to the sensitive determination of other targets via simply replacing the nanobody sequence, holding great promise in various applications, particularly in disease diagnosis.


Assuntos
Difusão Dinâmica da Luz , Limite de Detecção , alfa-Fetoproteínas , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/imunologia , Humanos , Imunoensaio/métodos , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/métodos , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/imunologia , Nanopartículas de Magnetita/química
4.
J Med Virol ; 96(6): e29732, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38874202

RESUMO

Neutralizing antibodies (NAbs) are considered the primary mechanism of vaccine-mediated protection against human papillomaviruses (HPV), the causative agent of cervical cancer. However, the minimum level of NAb needed for protection is currently unknown. The HPV pseudovirion-based neutralization assay (PBNA) is the gold standard method for assessing HPV antibody responses but is time-consuming and labor-intensive. With the development of higher valency HPV vaccines, alternative serological assays with the capacity for multiplexing would improve efficiency and output. Here we describe a multiplex bead-based immunoassay to characterize the antibody responses to the seven oncogenic HPV types (HPV16/18/31/33/45/52/58) contained in the current licensed nonavalent HPV vaccine. This assay can measure antibody isotypes and subclasses (total IgG, IgM, IgA1-2, IgG1-4), and can be adapted to measure other antibody features (e.g., Fc receptors) that contribute to vaccine immunity. When tested with serum samples from unvaccinated and vaccinated individuals, we found high concordance between HPV-specific IgG using this multiplex assay and NAbs measured with PBNA. Overall, this assay is high-throughput, sample-sparing, and time-saving, providing an alternative to existing assays for the measurement and characterization of HPV antibody responses.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Imunoglobulina G , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Humanos , Anticorpos Antivirais/sangue , Imunoensaio/métodos , Feminino , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Vacinas contra Papillomavirus/imunologia , Vacinas contra Papillomavirus/administração & dosagem , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Imunoglobulina G/sangue , Papillomaviridae/imunologia , Papillomavirus Humano
5.
Mikrochim Acta ; 191(7): 369, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834823

RESUMO

A trendsetting direct competitive-based biosensing tool has been developed and implemented for the determination of the polyunsaturated fatty acid arachidonic acid (ARA), a highly significant biological regulator with decisive roles in viral infections. The designed methodology involves a competitive reaction between the target endogenous ARA and a biotin-ARA competitor for the recognition sites of anti-ARA antibodies covalently attached to the surface of carboxylic acid-coated magnetic microbeads (HOOC-MµBs), followed by the enzymatic label of the biotin-ARA residues with streptavidin-horseradish peroxidase (Strep-HRP) conjugate. The resulting bioconjugates were magnetically trapped onto the sensing surface of disposable screen-printed carbon transducers (SPCEs) to monitor the extent of the biorecognition reaction through amperometry. The operational functioning of the exhaustively optimized and characterized immunosensing bioplatform was highly convenient for the quantitative determination of ARA in serum samples from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2-) and respiratory syncytial virus (RSV)-infected individuals in a rapid, affordable, trustful, and sensitive manner.


Assuntos
Ácido Araquidônico , Técnicas Biossensoriais , COVID-19 , SARS-CoV-2 , Humanos , Ácido Araquidônico/sangue , COVID-19/sangue , COVID-19/diagnóstico , COVID-19/imunologia , Técnicas Biossensoriais/métodos , SARS-CoV-2/imunologia , Peroxidase do Rábano Silvestre/química , Vírus Sinciciais Respiratórios/imunologia , Imunoensaio/métodos , Estreptavidina/química , Biotina/química , Limite de Detecção
6.
Mikrochim Acta ; 191(7): 370, 2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837084

RESUMO

The development of an ultrasensitive and precise measurement of a breast cancer biomarker (cancer antigen 15-3; CA15-3) in complex human serum is essential for the early diagnosis of cancer in groups of healthy populations and the treatment of patients. However, currently available testing technologies suffer from insufficient sensitivity toward CA15-3, which severely limits early large-scale screening of breast cancer patients. We report a versatile electrochemical immunoassay method based on atomically cobalt-dispersed nitrogen-doped carbon (Co-NC)-modified disposable screen-printed carbon electrode (SPCE) with alkaline phosphatase (ALP) and its metabolite, ascorbic acid 2-phosphate (AAP), as the electrochemical labeling and redox signaling unit for sensitive detection of low-abundance CA15-3. During electrochemical detection by differential pulse voltammetry (DPV), it was found that the Co-NC-SPCE electrode did not have a current signal response to the AAP substrate; however, it had an extremely favorable response current to ascorbic acid (AA). Based on the above principle, the target CA15-3-triggered immunoassay enriched ALP-catalyzed AAP produces a large amount of AA, resulting in a significant change in the system current signal, thereby realizing the highly sensitive detection of CA15-3. Under the optimal AAP substrate concentration and ALP catalysis time, the Co-NC-SPCE-based electrochemical immunoassay demonstrated a good DPV current for CA15-3 in the assay interval of 1.0 mU/mL to 10,000 mU/mL, with a calculated limit of detection of 0.38 mU/mL. Since Co-NC-SPCE has an excellent DPV current response to AA and employs split-type scheme, the constructed electrochemical immunoassay has the merits of high preciseness and anti-interference, and its clinical diagnostic results are comparable to those of commercial kits.


Assuntos
Ácido Ascórbico , Biomarcadores Tumorais , Neoplasias da Mama , Carbono , Cobalto , Técnicas Eletroquímicas , Mucina-1 , Nitrogênio , Humanos , Imunoensaio/métodos , Neoplasias da Mama/sangue , Mucina-1/sangue , Biomarcadores Tumorais/sangue , Técnicas Eletroquímicas/métodos , Carbono/química , Nitrogênio/química , Cobalto/química , Ácido Ascórbico/química , Ácido Ascórbico/sangue , Ácido Ascórbico/análogos & derivados , Feminino , Limite de Detecção , Fosfatase Alcalina/sangue , Fosfatase Alcalina/química , Eletrodos , Técnicas Biossensoriais/métodos
7.
Anal Chim Acta ; 1312: 342765, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38834279

RESUMO

The sensitive, accurate and rapid detection of carbohydrate antigen 125 (CA125) is essential for the early diagnosis and clinical management of ovarian cancer, but there is still challenge. Herein, a photoelectrochemical (PEC) immunosensor based on CdS/Bi2S3/NiS ternary sulfide heterostructured photocatalyst was presented for the detection of CA125. The CdS/Bi2S3/NiS was synthesized by a one-step hydrothermal approach. The heterojunction comprising of CdS and Bi2S3 could separate photogenerated carriers, the introduced narrow bandgap NiS could act as electron-conducting bridge to facilitate the transfer of interfacial photogenerated electrons, thereby improving the photoelectric conversion efficiency. Due to their synergistic effect, the photocurrent response produced by the composite was up to 14.6 times of pure CdS. On the basis, a PEC immunosensor was constructed by introducing the CA125 antibody through thioglycolic acid linkage. It was found that the resulting immunosensor showed good performance. Under the optimized conditions, its linear detection range was as wide as 1 pg mL-1-50 ng mL-1, and the detection limit was low to 0.85 pg mL-1. Furthermore, we experimentally tested its anti-interference, stability and reproducibility, and satisfactory results were achieved. The practicable feasibility of the sensor was confirmed by testing serum sample. Thus this work provided a simple, fast and enough sensitive approach for CA125 monitoring.


Assuntos
Bismuto , Antígeno Ca-125 , Compostos de Cádmio , Técnicas Eletroquímicas , Sulfetos , Compostos de Cádmio/química , Sulfetos/química , Humanos , Técnicas Eletroquímicas/métodos , Antígeno Ca-125/sangue , Antígeno Ca-125/análise , Bismuto/química , Limite de Detecção , Imunoensaio/métodos , Técnicas Biossensoriais/métodos
8.
Biotechnol J ; 19(6): e2400074, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38896409

RESUMO

The ELISA is the most worldwide method for immunoassay. However, the ELISA is losing ground due to low reproducibility of manual experimental processes in both R&D and IVD areas. An automated platform is a good solution, but there are still limitations owning to extremely high cost and requiring large space to set up especially for a small size laboratory. Here, we present a novel all-in-one platform called "VEUS" settable on the laboratory table that offers comprehensive automation of the entire multiplex immunoassay process by exploiting antibody conjugated magnetic particles, quality control and then immunoanalytical reaction, thereby enhancing detection sensitivity and high reproducibility. As a proof of concept, the system exhibits a sensitive LOD of 0.6 and 3.1 pg mL-1 within 1 h run, comparable precision that of molecular diagnostic systems based on PCR method, enabling rapid multiplex diagnosis of Influenza A, Influenza B, and COVID-19 viruses with similar symptoms. Through automation by the all-in-one system, it can be used by novice users, something innovative for immunoassays, relying heavily on user experience. Furthermore, it can contribute to streamline entire immunoassay processes of diverse biomarkers with high reproducibility and convenience in laboratories.


Assuntos
SARS-CoV-2 , Humanos , Imunoensaio/métodos , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Anticorpos Imobilizados/imunologia , Anticorpos Imobilizados/química , Reprodutibilidade dos Testes , COVID-19/diagnóstico , COVID-19/virologia , Ensaio de Imunoadsorção Enzimática/métodos , Vírus da Influenza A/imunologia , Vírus da Influenza B/imunologia , Automação Laboratorial/métodos , Limite de Detecção
9.
Mikrochim Acta ; 191(7): 364, 2024 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831034

RESUMO

CdIn2S4 and zinc tetrakis(4-carboxyphenyl)porphyrin (ZnTCPP) were synthesized by hydrothermal method, and an organic dye-sensitized inorganic semiconductor ZnTCPP/CdIn2S4 type II heterojunction was constructed on a fluorine-doped tin oxide (FTO) substrate electrode. A sandwich immunostructure for signal-attenuation photoelectrochemical (PEC) detection of cardiac troponin I (cTnI) was constructed using the ZnTCPP/CdIn2S4/FTO photoanode and a horseradish peroxidase (HRP)-ZnFe2O4-Ab2-bovine serum albumin (BSA) immunolabeling complex. The bioenzyme HRP and the HRP-like nanozyme ZnFe2O4 can co-catalyze the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 to produce an insoluble precipitate on the photoanode, thus notably reducing the anodic photocurrent for quantitative determination of cTnI. Under the optimal conditions, the photocurrent at 0 V vs. SCE in 0.1 M phosphate buffer solution (pH 7.40) containing 0.1 M ascorbic acid was linear with the logarithm of cTnI concentration from 500 fg mL-1 to 50.0 ng mL-1, and the limit of detection (LOD, S/N = 3) is 0.15 pg mL-1. Spiked recoveries were 95.1% ~ 104% for assay of cTnI in human serum samples.


Assuntos
Técnicas Eletroquímicas , Limite de Detecção , Compostos de Estanho , Troponina I , Troponina I/sangue , Humanos , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Compostos de Estanho/química , Catálise , Peroxidase do Rábano Silvestre/química , Naftóis/química , Metaloporfirinas/química , Eletrodos , Peróxido de Hidrogênio/química , Soroalbumina Bovina/química , Processos Fotoquímicos , Animais , Técnicas Biossensoriais/métodos , Semicondutores , Bovinos , Sulfetos/química , Porfirinas/química
10.
Biosens Bioelectron ; 260: 116436, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38824701

RESUMO

A mid-infrared label-free immunoassay-based biosensor is an effective device to help identify and quantify biomolecules. This biosensor employs a surface-enhanced infrared absorption spectroscopy, which is a highly potent sensing technique for detecting minute quantities of analytes. In this study, a biosensor was constructed using a metamaterial absorber, which facilitated strong coupling effects. For maximum coupling effect, it is necessary to enhance the near-field intensity and the spatial and spectral overlap between the optical cavity resonance and the vibrational mode of the analyte. Due to significant peak splitting, conventional baseline correction methods fail to adequately analyze such a coupling system. Therefore, we employed a coupled harmonic oscillation model to analyze the spectral distortion resulting from the peak splitting induced by the strong coupling effect. The proposed biosensor with a thrombin-binding aptamer-based immunoassay could achieve a limit of detection of 267.4 pM, paving the way for more efficient protein detection in clinical practice.


Assuntos
Técnicas Biossensoriais , Limite de Detecção , Técnicas Biossensoriais/métodos , Imunoensaio/métodos , Imunoensaio/instrumentação , Humanos , Aptâmeros de Nucleotídeos/química , Desenho de Equipamento , Espectrofotometria Infravermelho , Proteínas/análise , Trombina/análise
11.
Biochem Med (Zagreb) ; 34(2): 020706, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38882584

RESUMO

Introduction: Many studies report vitamin D (25-OH-D) deficiency, although there is no consensus among scientific societies on cut-offs and reference intervals (RI). The aim of this study is to establish and compare RI for serum 25-OH-D by direct and indirect methods. Materials and methods: Two studies were performed in Zaragoza (Spain). A retrospective study (N = 7222) between January 2017 and April 2019 was used for RI calculation by indirect method and a prospective study (N = 312) with healthy volunteers recruited in August 2019 and February 2020 for direct method. Seasonal differences were investigated. Measurements were performed on Cobas C8000 (Roche-Diagnostics, Basel, Switzerland) using electrochemiluminescence immunoassay technology. Results: Reference intervals (2.5-97.5 percentile and corresponding 95% confidence intervals, CIs) were as follows: by indirect method 5.6 ng/mL (5.4 to 5.8) - 57.2 ng/mL (55.2 to 59.8), in winter 5.4 ng/mL (5.2 to 5.7) - 55.7 ng/mL (53.6 to 58.4), while in summer 5.9 ng/mL (5.4 to 6.2) - 59.9 ng/mL (56.3 to 62.9). By direct method 9.0 ng/mL (5.7 to 9.5) - 41.4 ng/mL (37.6 to 48.0), in winter 7.4 ng/mL (3.9 to 8.6) - 34.6 ng/mL (30.6 to 51.5), while in summer 13.3 ng/mL (10.1 to 14.1) - 44.1 ng/mL (38.9 to 66.0). In both methods, RIs were higher in summer. A significant difference was observed in 25-OH-D median values between the two methods (P < 0.001). Conclusions: Reference interval calculation according to the studied area may be a useful tool to adapt the deficiency cut-offs for 25-OH-D. Our data support 25-OH-D values over 12.0 ng/mL for healthy population as sufficient, therefore current recommendations should be updated. In addition, differences in seasonality should be taken into account.


Assuntos
Deficiência de Vitamina D , Vitamina D , Humanos , Vitamina D/sangue , Vitamina D/análogos & derivados , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia , Deficiência de Vitamina D/diagnóstico , Valores de Referência , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Idoso , Estações do Ano , Adulto Jovem , Pandemias , Adolescente , Imunoensaio/normas , Espanha/epidemiologia
12.
J Pharm Biomed Anal ; 247: 116271, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38850850

RESUMO

Sirolimus (SRL) is commonly used in transplant patients to prevent organ transplant rejection. The current guidelines recommend to perform SRL therapeutic drug monitoring regularly to improve treatment outcomes and avoid adverse effects. Consequently, a precise and accurate method for determining SRL is crucial in clinical practice. Currently, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassays have been widely adopted for determining SRL concentrations. However, previous studies have shown that immunoassays exhibit a positive bias compared to LC-MS/MS. As the new updated version of the EMIT-based Viva-E® System (SVPS), this study aims to compare SRL blood concentrations measured by the SVPS and LC-MS/MS. The residual whole-blood samples obtained from transplant patients were simultaneously analyzed using the SVPS and LC-MS/MS, respectively. The correlation between the two assays was analyzed using the linear regression analysis and Deming linear regression. The Pearson correlation coefficient and Intraclass correlation coefficient (ICC) analysis were executed. The Paired Wilcoxon test and Bland-Altman analysis were performed to assess the concordance between the two methods. The SVPS considerably increased SRL concentration value by 46.62 % as compared to the LC-MS/MS method. When SRL concentrations measured by the SVPS were above 4.0 ng/mL, there was no significant difference between the corrected SVPS concentrations after using the Deming linear regression equation, indicating their interchangeability. Given the significant disparities observed between EMIT and LC-MS/MS, it is crucial to indicate the methodology and instruments in both TDM reports and future clinical guidelines. Our study also provides the conversion formulas between the SVPS and LC-MS/MS, which can be applied as a reference for different clinical centers.


Assuntos
Monitoramento de Medicamentos , Imunossupressores , Sirolimo , Espectrometria de Massas em Tandem , Humanos , Espectrometria de Massas em Tandem/métodos , Sirolimo/sangue , Cromatografia Líquida/métodos , Monitoramento de Medicamentos/métodos , Imunossupressores/sangue , Imunoensaio/métodos , Masculino , Feminino , Reprodutibilidade dos Testes , Povo Asiático , China , Pessoa de Meia-Idade , Adulto , Transplante de Órgãos/métodos , População do Leste Asiático , Espectrometria de Massa com Cromatografia Líquida
13.
Harm Reduct J ; 21(1): 115, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38877522

RESUMO

BACKGROUND: Fentanyl test strips (FTS) are lateral flow immunoassay strips designed for detection of ng/mL levels of fentanyl in urine. In 2021, the US Centers for Disease Control and the Substance Abuse and Mental Health Administration stated that federal funds could be used for procurement of FTS for harm reduction strategies approved by the government such as drug checking. The market for FTS has expanded rapidly in the US and Canada. However, there is no regulatory oversight by either government to ensure proper function of FTS that are being marketed for drug checking. MAIN BODY: Many brands of FTS have rapidly entered the harm reduction market, creating concerns about the reproducibility and accuracy of their performance from brand to brand and lot to lot. Some examples are provided in this Comment. Similar problems with product quality were observed in the mid 2000's when lateral flow immunoassays for malaria were funded in many countries and again in 2020, when COVID-19 tests were in huge demand. The combination of high demand and low levels of regulation and enforcement led some manufacturers to join the goldrush without adequate field testing or quality assurance. We argue that the harm reduction community urgently needs to set a lot checking program in place. A set of simple protocols for conducting the tests and communicating the results have been developed, and are described in the following Perspectives paper in this issue. CONCLUSION: In the absence of governmental regulation and enforcement, the harm reduction community should implement a FTS lot checking program. Based on previous experience with the malaria diagnostic lot checking program, this inexpensive effort could identify products that are not suitable for harm reduction applications and provide valuable feedback to manufacturers. Dissemination of the results will help harm reduction organizations to ensure that FTS they use for drug checking are fit for the purpose.


Assuntos
Fentanila , Redução do Dano , Fitas Reagentes , Humanos , Fentanila/urina , Fentanila/análise , Reprodutibilidade dos Testes , Detecção do Abuso de Substâncias/métodos , Imunoensaio/métodos , Analgésicos Opioides/urina , Analgésicos Opioides/análise , COVID-19 , América do Norte
14.
Commun Biol ; 7(1): 677, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38830977

RESUMO

We present a quantitative sandwich immunoassay for CD63 Extracellular Vesicles (EVs) and a constituent surface cargo, EGFR and its activity state, that provides a sensitive, selective, fluorophore-free and rapid alternative to current EV-based diagnostic methods. Our sensing design utilizes a charge-gating strategy, with a hydrophilic anion exchange membrane functionalized with capture antibodies and a charged silica nanoparticle reporter functionalized with detection antibodies. With sensitivity and robustness enhancement by the ion-depletion action of the membrane, this hydrophilic design with charged reporters minimizes interference from dispersed proteins, thus enabling direct plasma analysis without the need for EV isolation or sensor blocking. With a LOD of 30 EVs/µL and a high relative sensitivity of 0.01% for targeted proteomic subfractions, our assay enables accurate quantification of the EV marker, CD63, with colocalized EGFR by an operator/sample insensitive universal normalized calibration. We analysed untreated clinical samples of Glioblastoma to demonstrate this new platform. Notably, we target both total and "active" EGFR on EVs; with a monoclonal antibody mAb806 that recognizes a normally hidden epitope on overexpressed or mutant variant III EGFR. Analysis of samples yielded an area-under-the-curve (AUC) value of 0.99 and a low p-value of 0.000033, surpassing the performance of existing assays and markers.


Assuntos
Receptores ErbB , Vesículas Extracelulares , Glioblastoma , Tetraspanina 30 , Humanos , Glioblastoma/sangue , Glioblastoma/diagnóstico , Glioblastoma/metabolismo , Tetraspanina 30/metabolismo , Receptores ErbB/metabolismo , Vesículas Extracelulares/metabolismo , Imunoensaio/métodos , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/diagnóstico
15.
Mikrochim Acta ; 191(7): 381, 2024 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858277

RESUMO

Nanosized sodium bismuth perovskite titanate (NBT) was synthesized and first used as the electrochemical immune sensing platform for the sensitive detection of carcinoembryonic antigen (CEA). Gold nanoparticles (Au NPs) grew on the surface of NBT through forming Au-N bond to obtain Au@NBT, and a label-free electrochemical immunosensor was proposed using Au@NBT as an immunosensing recognizer towards CEA. The well-ordered crystal structure of NBT was not changed at all after the modification of Au NPs outside, but significantly improved the conductivity, catalytic activity, and biocompatibility of the Au@NBT-modified electrode. The unique cubic crystal nanostructure of NBT offered a large active area for both Au NP modification and the subsequent immobilization of biomolecules over the electrode surface, triggering the effective generation of promising properties of the proposed Au@NBT-based electrochemical immunosensor. As expected, favorable detection performances were achieved using this immunosensor towards CEA detection, where a good linear relationship between the current response and CEA concentration was obtained in the concentration range 10 fg mL-1 to 100 ng mL-1 with a low detection limit (LOD) of 13.17 fg mL-1. Also, the significantly enhanced selectivity, and stability guaranteed the promising electrochemical properties of this immunosensor. Furthermore, the analysis of real serum samples verified the high feasibility of this new method in clinical CEA detection. This work opens a new window for the application of nanoperovskite in the early detection of CEA.


Assuntos
Bismuto , Antígeno Carcinoembrionário , Técnicas Eletroquímicas , Ouro , Limite de Detecção , Nanopartículas Metálicas , Titânio , Antígeno Carcinoembrionário/sangue , Antígeno Carcinoembrionário/imunologia , Titânio/química , Técnicas Eletroquímicas/métodos , Humanos , Imunoensaio/métodos , Ouro/química , Nanopartículas Metálicas/química , Bismuto/química , Técnicas Biossensoriais/métodos , Óxidos/química , Anticorpos Imobilizados/imunologia , Compostos de Cálcio/química , Eletrodos
16.
Anal Chem ; 96(23): 9503-9511, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38780632

RESUMO

In this work, a micron-sized flower-like metal-organic frameworks (MOFs)-based boronate-affinity sandwich-type immunoassay was fabricated for the dual-mode glycoprotein assay. For proof of concept, the flower-like MOFs were synthesized from transition Cu nodes and tetrakis (4-carboxyphenyl) porphyrin (TCPP) ligands by spontaneous standing assembly. In addition, the specificity toward glycoprotein involved the antigen recognition as well as covalent bonding via the boronate-glycan affinity, and the immediate signal responses were initiated by textural decomposition of the flower-like MOFs. Intriguingly, Cu nodes, of which the valence state is dominant by CuI species, can endow the Fenton-like catalytic reaction of the fluorogenic substrate for generating fluorescence signals. For benefits, TCPP ligands, in which each TCPP molecule has four guest donors, can provide multiple valences for the assembly of cyclodextrin-capped gold nanoparticles via host-guest interaction for colorimetry output. Albeit important, the scaling micrometer patterns for the flower-like MOFs carrying numerous Cu nodes and TCPP ligands can also function as amplifying units, signifying the output signal. The detection limit of the dual-mode glycoprotein assay can reach 10.5 nM for the fluorescence mode and 18.7 nM for the colorimetry mode, respectively. Furthermore, the merits of harvesting different signal generators toward the multimodal readout patterns can allow the mutual verification and make the analytical results more reliable. Collectively, our proposed assay may offer a new idea in combining the inherent textural merits from MOFs for dual signal generators, which can also emphasize accurate detection capability for glycoprotein assay.


Assuntos
Glicoproteínas , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Glicoproteínas/análise , Glicoproteínas/química , Cobre/química , Porfirinas/química , Imunoensaio/métodos , Ouro/química , Nanopartículas Metálicas/química , Humanos , Ácidos Borônicos/química , Limite de Detecção , Tamanho da Partícula
17.
Anal Chim Acta ; 1310: 342717, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811143

RESUMO

Parathion is one of organophosphorus pesticide, which has been prohibited in agricultural products due to its high toxicity to human beings. However, there are still abuse cases for profit in agricultural production. Hence, we established nanobodies-based colloidal gold immunochromatographic assay (GICA) in which nanobodies (Nbs) as an excellent recognition element, greatly improving the stability and sensitivity of ICA. Under the optimal conditions, the developed Nbs-based GICA showed a cut-off value of 50 ng/mL for visual judgment and a half-inhibitory concentration (IC50) of 2.39 ng/mL for quantitative detection. The limit of detection (LOD) was as low as 0.15 ng/mL which was significantly 50-fold higher sensitivity than the commercial mAb-ICA. Additionally, this method exhibited good recoveries for the detection of cabbage, cucumber, and orange samples and excellent correlation with the UPLC-MS/MS method. The results showed that this method developed in this work based on nanobody can be used in practical detection of parathion in foods and nanobody is novel prospective antibody resource for immunoassays of chemical contaminants.


Assuntos
Cromatografia de Afinidade , Coloide de Ouro , Paration , Anticorpos de Domínio Único , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/química , Coloide de Ouro/química , Paration/análise , Cromatografia de Afinidade/métodos , Imunoensaio/métodos , Limite de Detecção , Contaminação de Alimentos/análise
18.
Anal Chim Acta ; 1310: 342723, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811138

RESUMO

BACKGROUND: Eugenol compounds (EUGs), which share chemical similarities with eugenol, belong to a group of phenolic compounds primarily found in clove oil. They are highly valued by fish dealers due to their exceptional anesthetic properties, playing a crucial role in reducing disease incidence and mortality during the transportation of live fish. Despite their widespread use, the safety of EUGs remains a contentious topic, raising concerns about the safety of aquatic products. This underscores the need for efficient and sensitive analytical methods for detecting EUGs. RESULTS: Nanomaterial-based ratiometric fluorescence immunoassay has gained increasing attention due to its integration of the immunoassay's excellent specificity and compatibility for high-throughput analysis, coupled with the exceptional sensitivity and anti-interference capabilities of ratiometric fluorescence assays. In this study, we developed a sensitive ratiometric fluorescence immunoassay for screening five EUGs. This method employs a broad-specificity monoclonal antibody (mAb) as a recognition reagent, selective for five EUGs. It leverages the horseradish peroxidase (HRP)-triggered formation of fluorescent 2,3-diaminophenazine (DAP) and the quenching of fluorescent gold clusters (Au NCs) for detection. The assay's detection limits for eugenol, isoeugenol, eugenol methyl eugenol, methyl isoeugenol, and acetyl isoeugenol in tilapia fish and shrimp were found to be 9.8/19.5 µg/kg, 0.11/0.22 µg/kg, 19/36 Tilapia ng/kg, 8/16 ng/kg, and 3.0/6.1 µg/kg, respectively. Furthermore, when testing spiked Tilapia fish and shrimp samples, recoveries ranging from 84.1 to 111.9 %, with the coefficients of variation staying below 7.1 % was achieved. SIGNIFICANCE: This work introduces an easy-to-use, broad-specificity, and highly sensitive method for the screening of five EUGs at a pg/mL level, which not only provides a high-throughput strategy for screening eugenol-type fish anesthetics in aquatic products, but also can serve as a benchmark for developing immunoassays for other small molecular pollutants, rendering potent technological support for guarding food safety and human health.


Assuntos
Eugenol , Ouro , Nanopartículas Metálicas , Eugenol/análise , Eugenol/análogos & derivados , Eugenol/química , Ouro/química , Nanopartículas Metálicas/química , Animais , Imunoensaio/métodos , Limite de Detecção
19.
Anal Methods ; 16(22): 3539-3550, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38780022

RESUMO

Dengue virus (DENV) is the most prevalent global arbovirus, exhibiting a high worldwide incidence with intensified severity of symptoms and alarming mortality rates. Faced with the limitations of diagnostic methods, an optical and electrochemical biosystem was developed for the detection of DENV genotypes 1 and 2, using cysteine (Cys), cadmium telluride (CdTe) quantum dots, and anti-DENV antibodies. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), surface plasmon resonance (SPR), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the immunosensor. The AFM and SPR results demonstrated discernible topographic and angular changes confirming the biomolecular recognition. Different concentrations of DENV-1 and DENV-2 were evaluated (0.05 × 106 to 2.0 × 106 PFU mL-1), resulting in a maximum anodic shift (ΔI%) of 263.67% ± 12.54 for DENV-1 and 63.36% ± 3.68 for DENV-2. The detection strategies exhibited a linear response to the increase in viral concentration. Excellent linear correlations, with R2 values of 0.95391 for DENV-1 and 0.97773 for DENV-2, were obtained across a broad concentration range. Data analysis demonstrated high reproducibility, displaying relative standard deviation values of 3.42% and 3.62% for Cys-CdTe-antibodyDENV-1-BSA and Cys-CdTe-antibodyDENV-2-BSA systems. The detection limits were 0.34 × 106 PFU mL-1 and 0.02 × 106 PFU mL-1, while the quantification limits were set at 1.49 × 106 PFU mL-1 and 0.06 × 106 PFU mL-1 for DENV-1 and DENV-2, respectively. Therefore, the biosensing apparatus demonstrates analytical effectiveness in viral screening and can be considered an innovative solution for early dengue diagnosis, contributing to global public health.


Assuntos
Técnicas Biossensoriais , Vírus da Dengue , Dengue , Telúrio , Vírus da Dengue/isolamento & purificação , Vírus da Dengue/imunologia , Técnicas Biossensoriais/métodos , Telúrio/química , Humanos , Dengue/diagnóstico , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Pontos Quânticos/química , Ressonância de Plasmônio de Superfície/métodos , Cisteína/química , Compostos de Cádmio/química , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/análise , Imunoensaio/métodos , Imunoensaio/instrumentação , Limite de Detecção , Microscopia de Força Atômica
20.
PLoS Negl Trop Dis ; 18(5): e0012174, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38748731

RESUMO

BACKGROUND: In the last two decades, several rapid lateral flow immunoassays (LFIs) for the diagnosis of human leptospirosis were developed and commercialized. However, the accuracy and reliability of these LFIs are not well understood. In this study, we aimed to evaluate the accuracy of leptospirosis LFIs as well as the factors affecting the test efficiency using systematic review and meta-analysis. METHODS AND RESULTS: Original articles reporting the accuracy of human leptospirosis LFIs against microagglutination tests (MAT) or immunofluorescent assays (IFA) were searched from PubMed, Embase, and Scopus, and selected as per pre-set inclusion and exclusion criteria. A total of 49 data entries extracted from 24 eligible records published between 2003 and 2023 were included for meta-analysis. A meta-analysis was performed using STATA. The quality of the included studies was assessed according to the revised QUADAS-2. Only nine studies (32.1%) were considered to have a low risk of bias and no concern for applicability. Pooled sensitivity and specificity were calculated to be 68% (95% confidence interval, CI: 57-78) and 93% (95% CI: 90-95), respectively. However, the ranges of sensitivity (3.6 - 100%) and specificity (53.5 - 100%) of individual entries are dramatically broad, possibly due to the heterogeneity found in both study designs and LFIs themselves. Subgroup analysis demonstrated that IgM detection has better sensitivity than detection of IgG alone. Moreover, the test performance seems to be unaffected by samples from different phases of infection. CONCLUSIONS: The pooled specificity of LFIs observed is somewhat acceptable, but the pooled sensitivity is low. These results, however, must be interpreted with caution because of substantial heterogeneity. Further evaluations of the LFIs with well-standardized design and reference test will be needed for a greater understanding of the test performance. Additionally, IgM detection type should be employed when leptospirosis LFIs are developed in the future.


Assuntos
Leptospirose , Sensibilidade e Especificidade , Leptospirose/diagnóstico , Leptospirose/imunologia , Humanos , Imunoensaio/métodos , Anticorpos Antibacterianos/sangue , Leptospira/imunologia , Leptospira/isolamento & purificação , Reprodutibilidade dos Testes
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