Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 216
Filtrar
1.
Bioorg Med Chem Lett ; 106: 129757, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38636718

RESUMO

9-cyanopyronin is a promising scaffold that exploits resonance Raman enhancement to enable sensitive, highly multiplexed biological imaging. Here, we developed cyano-Hydrol Green (CN-HG) derivatives as resonance Raman scaffolds to expand the color palette of 9-cyanopyronins. CN-HG derivatives exhibit sufficiently long wavelength absorption to produce strong resonance Raman enhancement for near-infrared (NIR) excitation, and their nitrile peaks are shifted to a lower frequency than those of 9-cyanopyronins. The fluorescence of CN-HG derivatives is strongly quenched due to the lack of the 10th atom, unlike pyronin derivatives, and this enabled us to detect spontaneous Raman spectra with high signal-to-noise ratios. CN-HG derivatives are powerful candidates for high performance vibrational imaging.

2.
Curr Top Med Chem ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38584544

RESUMO

This review explores the advancements in nanomaterial-based electrochemical sensors for the multiplex detection of medicinal compounds. The growing demand for efficient and selective detection methods in the pharmaceutical field has prompted significant research into the development of electrochemical sensors employing nanomaterials. These materials, defined as functional materials with at least one dimension between 1 and 100 nanometers, encompass metal nanoparticles, polymers, carbon-based nanocomposites, and nano-bioprobes. These sensors are characterized by their enhanced sensitivity and selectivity, playing a crucial role in simultaneous detection and offering a comprehensive analysis of multiple medicinal complexes within a single sample. The review comprehensively examines the design, fabrication, and application of nanomaterial- based electrochemical sensors, focusing on their ability to achieve multiplex detection of various medicinal substances. Insights into the strategies and nanomaterials employed for enhancing sensor performance are discussed. Additionally, the review explores the challenges and future perspectives of this evolving field, highlighting the potential impact of nanomaterial-based electrochemical sensors on the advancement of medicinal detection technologies.

3.
Sensors (Basel) ; 24(5)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38474919

RESUMO

One of the most consumed foods is milk and milk products, and guaranteeing the suitability of these products is one of the major concerns in our society. This has led to the development of numerous sensors to enhance quality controls in the food chain. However, this is not a simple task, because it is necessary to establish the parameters to be analyzed and often, not only one compound is responsible for food contamination or degradation. To attempt to address this problem, a multiplex analysis together with a non-directed (e.g., general parameters such as pH) analysis are the most relevant alternatives to identifying the safety of dairy food. In recent years, the use of new technologies in the development of devices/platforms with optical or electrochemical signals has accelerated and intensified the pursuit of systems that provide a simple, rapid, cost-effective, and/or multiparametric response to the presence of contaminants, markers of various diseases, and/or indicators of safety levels. However, achieving the simultaneous determination of two or more analytes in situ, in a single measurement, and in real time, using only one working 'real sensor', remains one of the most daunting challenges, primarily due to the complexity of the sample matrix. To address these requirements, different approaches have been explored. The state of the art on food safety sensors will be summarized in this review including optical, electrochemical, and other sensor-based detection methods such as magnetoelastic or mass-based sensors.


Assuntos
Contaminação de Alimentos , Inocuidade dos Alimentos , Animais , Contaminação de Alimentos/análise , Leite/química
4.
Talanta ; 273: 125868, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38458085

RESUMO

Magnetic nanoparticle (MNP)-based immunochromatographic tests (ICTs) display long-term stability and an enhanced capability for multiplex biomarker detection, surpassing conventional gold nanoparticles (AuNPs) and fluorescence-based ICTs. In this study, we innovatively developed zwitterionic silica-coated MNPs (MNP@Si-Zwit/COOH) with outstanding antifouling capabilities and effectively utilised them for the simultaneous identification of the nucleocapsid protein (N protein) of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) and influenza A/B. The carboxyl-functionalised MNPs with 10% zwitterionic ligands (MNP@Si-Zwit 10/COOH) exhibited a wide linear dynamic detection range and the most pronounced signal-to-noise ratio when used as probes in the ICT. The relative limit of detection (LOD) values were achieved in 12 min by using a magnetic assay reader (MAR), with values of 0.0062 ng/mL for SARS-CoV-2 and 0.0051 and 0.0147 ng/mL, respectively, for the N protein of influenza A and influenza B. By integrating computer vision and deep learning to enhance the image processing of immunoassay results for multiplex detection, a classification accuracy in the range of 0.9672-0.9936 was achieved for evaluating the three proteins at concentrations of 0, 0.1, 1, and 10 ng/mL. The proposed MNP-based ICT for the multiplex diagnosis of biomarkers holds substantial promise for applications in both medical institutions and self-administered diagnostic settings.


Assuntos
Aprendizado Profundo , Influenza Humana , Nanopartículas Metálicas , Humanos , Ouro/química , Nanopartículas Metálicas/química , Influenza Humana/diagnóstico , Imunoensaio/métodos , Biomarcadores , Fenômenos Magnéticos
5.
J Hazard Mater ; 469: 133893, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38452684

RESUMO

Sensitive and rapid identification of volatile organic compounds (VOCs) at ppm level with complex composition is vital in various fields ranging from respiratory diagnosis to environmental safety. Herein, we demonstrate a SERS gas sensor with size-selective and multiplexed identification capabilities for VOCs by executing the pre-enrichment strategy. In particular, the macro-mesoporous structure of graphene aerogel and micropores of metal-organic frameworks (MOFs) significantly improved the enrichment capacity (1.68 mmol/g for toluene) of various VOCs near the plasmonic hotspots. On the other hand, molecular MOFs-based filters with different pore sizes could be realized by adjusting the ligands to exclude undesired interfering molecules in various detection environments. Combining these merits, graphene/AuNPs@ZIF-8 aerogel gas sensor exhibited outstanding label-free sensitivity (up to 0.1 ppm toluene) and high stability (RSD=14.8%, after 45 days storage at room temperature for 10 cycles) and allowed simultaneous identification of multiple VOCs in a single SERS measurement with high accuracy (error < 7.2%). We visualize that this work will tackle the dilemma between sensitivity and detection efficiency of gas sensors and will inspire the design of next-generation SERS technology for selective and multiplexed detection of VOCs.

6.
Biosens Bioelectron ; 254: 116187, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38518558

RESUMO

The expansion of large-scale aquaculture has exacerbated the challenge of aquatic diseases, resulting in substantial economic losses annually. Currently, traditional laboratory-based diagnostic methods are time-consuming and costly, hindering on-site testing for individual farmers. We address this issue by developing a state-of-the-art handheld isothermal nucleic acid amplification device (WeD-1) capable of fluorescence tracking of reactions and integrating it with an enhanced one-pot Prokaryotic Argonaute based nucleic acid detection method, enabling duplex visual detection of aquatic pathogens. WeD-1 is portable, reusable, user-friendly, and cost-effective, offering real-time smartphone interaction and enabling real-time fluorescence observation during the reaction. The enhanced one-pot Loop-Mediated Isothermal Amplification (LAMP)-PfAgo method, incorporating paraffin-encapsulated lyophilized PfAgo protein, achieves precise target-specific cleavage, significantly enhancing multiplex nucleic acid detection. This innovation streamlines on-site testing, negating the need for specialized laboratory conditions while ensuring an aerosol-free system. With newly developed and highly sensitive LAMP primer sets, our compact WeD-1/LAMP-PfAgo nucleic acid rapid testing system exhibits remarkable sensitivity, readily detecting aquatic pathogens with naked eyes from rapidly prepared fish and shrimp samples within 40 min, even when the Ct values are as high as 34.


Assuntos
Técnicas Biossensoriais , Ácidos Nucleicos , Animais , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , Sensibilidade e Especificidade
7.
ACS Sens ; 9(3): 1349-1358, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38437790

RESUMO

At present, traditional analytical methods suffer from issues such as complex operation, expensive equipment, and a lengthy testing time. Electrochemical sensors have shown great advantages and application potential as an alternative solution. In this study, we proposed a novel semiautomated electrochemical sensor array (SAESA) platform. The sensor array was fabricated using screen-printed technology with a tubular design where all electrodes were printed on the inner wall. The integration of the tubular sensor array with a pipet allows for a semiautomated process including sampling and rinsing, which simplifies operation and reduces overall time. Each working electrode in the tubular sensor array underwent distinct decoration to get specific sensing responses toward the target analytes in a mixture environment (e.g., blood samples). To demonstrate the applicability of the developed sensing platform for simultaneous multianalyte detection, we chose antibiotic treatment for inflammatory infection as a model scenario and continuously measured three biomarkers, namely, tigecycline (TGC), procalcitonin (PCT), and alanine aminotransferase (ALT). The detection limits were 0.3 µM, 0.3 ng/L, and 2.76 U/L, respectively. The developed semiautomated electrochemical sensor array exhibits characteristics such as rapid and simple operation, portability, good selectivity, and excellent stability.


Assuntos
Antibacterianos , Biomarcadores , Eletrodos
8.
ACS Sens ; 9(3): 1290-1300, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38478991

RESUMO

With the emergence of microRNA (miRNA) as a promising biomarker in cancer diagnosis, it is significant to develop multiple analyses of miRNAs. However, it still faces difficulties in ensuring the sensitivity and accuracy during multiplex detection owing to the low abundance and experimental deviation of miRNAs. In this work, a flexible-arranged biomimetic array integrated with parallel entropy-driven circuits (EDCs) was developed for ultrasensitive, multiplex, reliable, and high-throughput detection of miRNAs. The biomimetic array was fabricated by arrangement of various photonic crystals (PCs) for adjustable photonic band gaps (PBGs) and specific fluorescence enhancement. Meanwhile, two cancer-related miRNAs and one reference miRNA were introduced as multiple analytes as a proof-of-concept. The parallel EDCs with negligible crosstalk were designed based on the modular property. Because of the one-to-one match between the emitted fluorescence of parallel EDCs and the PBGs of the flexible-arranged biomimetic array, the generated fluorescence signal triggered by target miRNAs can be enhanced on the corresponding domain of the array. Furthermore, the amplified signal of the array was detected with high-throughput scanning, which could reveal specific information on cancer-related miRNAs as well as reference miRNA, enhancing the abundance and reliability of the analysis. The proposed array has the merits of a modular design, flexible deployment, simple operation (nonenzymatic and isothermal), improved accuracy, high sensitivity, and multiplex analysis, showing potential in disease diagnosis.


Assuntos
MicroRNAs , Neoplasias , Humanos , MicroRNAs/análise , Entropia , Reprodutibilidade dos Testes , Biomimética , Neoplasias/diagnóstico
9.
Biosens Bioelectron ; 253: 116172, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38460210

RESUMO

Simultaneous multiplexed analysis can provide comprehensive information for disease diagnosis. However, the current multiplex methods rely on sophisticated barcode technology, which hinders its wider application. In this study, an ultrasimple size encoding method is proposed for multiplex detection using a wedge-shaped microfluidic chip. Driving by negative pressure, microparticles are naturally arranged in distinct stripes based on their sizes within the chip. This size encoding method demonstrates a high level of precision, allowing for accuracy in distinguishing 3-5 sizes of microparticles with a remarkable accuracy rate of up to 99%, even the microparticles with a size difference as small as 0.5 µm. The entire size encoding process is completed in less than 5 min, making it ultrasimple, reliable, and easy to operate. To evaluate the function of this size encoding microfluidic chip, three commonly co-infectious viruses' nucleic acid sequences (including complementary DNA sequences of HIV and HCV, and DNA sequence of HBV) are employed for multiplex detection. Results indicate that all three DNA sequences can be sensitively detected without any cross-interference. This size-encoding microfluidic chip-based multiplex detection method is simple, rapid, and high-resolution, its successful application in serum samples renders it highly promising for potential clinical promotion.


Assuntos
Técnicas Biossensoriais , Técnicas Analíticas Microfluídicas , Microfluídica , Sequência de Bases , Técnicas Analíticas Microfluídicas/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos
10.
ACS Synth Biol ; 13(3): 837-850, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38349963

RESUMO

The World Health Organization's global initiative toward eliminating high-risk Human Papillomavirus (hrHPV)-related cancers recommends DNA testing over visual inspection in all settings for primary cancer screening and HPV eradication by 2100. However, multiple hrHPV types cause different types of cancers, and there is a pressing need for an easy-to-use, multiplex point-of-care diagnostic platform for detecting different hrHPV types. Recently, CRISPR-Cas systems have been repurposed for point-of-care detection. Here, we established a CRISPR-Cas multiplexed diagnostic assay (CRISPRD) to detect cervical cancer-causing hrHPVs in one reaction (one-pot assay). We harnessed the compatibility of thermostable AapCas12b, TccCas13a, and HheCas13a nucleases with isothermal amplification and successfully detected HPV16 and HPV18, along with an internal control in a single-pot assay with a limit of detection of 10 copies and 100% specificity. This platform offers a rapid and practical solution for the multiplex detection of hrHPVs, which may facilitate large-scale hrHPV point-of-care screening. Furthermore, the CRISPRD platform programmability enables it to be adapted for the multiplex detection of any two nucleic acid biomarkers as well as internal control.


Assuntos
Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Papillomavirus Humano , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/genética , Infecções por Papillomavirus/prevenção & controle , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Testes Imediatos , Papillomavirus Humano 16/genética
12.
Biosens Bioelectron ; 250: 116055, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38266617

RESUMO

This study introduces an innovative detection system for multiple cancer biomarkers, employing transcription isothermal amplification methods in conjunction with a tetrahedral DNA nanostructure (TDN). We demonstrate that TDN enhances various transcription isothermal amplification methods by placing DNA probes in proximity. Notably, the TDN-enhanced split T7 promoter-based isothermal transcription amplification with light-up RNA aptamer (STAR) system stands out for its optimal performance and operational simplicity, especially in identifying non-coding RNAs such as microRNAs and long non-coding RNAs (lncRNAs). Multiplex detection of lncRNAs was also achieved by generating distinct light-up RNA aptamers, each emitting unique fluorescence signals. The system effectively identified the target lncRNAs, demonstrating high sensitivity and selectivity in both cell lines and clinical samples. The system, utilizing the single enzyme T7 RNA polymerase, can be easily tailored for alternative targets by substituting target-specific sequences in DNA probes and seamlessly integrated with other isothermal amplification methods for greater sensitivity and accuracy in the detection of multiple cancer biomarkers.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanoestruturas , Neoplasias , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Técnicas Biossensoriais/métodos , DNA/genética , DNA/química , Aptâmeros de Nucleotídeos/química , Biomarcadores Tumorais/genética , Sondas de DNA , Técnicas de Amplificação de Ácido Nucleico/métodos
13.
ACS Sens ; 9(1): 29-41, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38199966

RESUMO

Heart failure (HF) is a life-threatening syndrome. Timely and accurate bedside monitoring of the occurrence and progression of HF via measurements of multiple HF-related biomarkers remains a challenge. Here, we report a triple cascade quantum-strip (TCQS) sensing strategy for the rapid and selective multiplex-tracing of three clinically validated HF biomarkers (BNP/NT-proBNP/ST2) in serum. High selectivity to the three biomarkers is achieved by controlling the individual recognition ability of three target-specific quantum immunoprobes and tuning their simultaneous use to BNP/NT-proBNP/ST2 recognition without mutual interference, which allows the three biomarkers to be directly enriched from serum samples. Benefiting from the fast release-binding kinetics of target-bound immunoprobes on TCQS, recognizable fluorescent signals can be rapidly read out through combining with a self-designed smartphone-based portable reader. This rapid and simple profiling strategy results in good specificity and sensitivity with LODs of 0.097, 0.072, and 0.948 ng/mL for BNP, NT-proBNP, and ST2, respectively, which match the need of clinical applications. Real serum samples are tested with an accuracy of 92.86% for HF diagnosis, validating the capability of the smartphone-read TCQS for practical applications. In particular, the simultaneous detection of the TCQS sensing strategy for BNP/NT-proBNP/ST2 will facilitate the accurate monitoring of HF occurrence, risk stratification, progression, and prognosis as a powerful POCT tool.


Assuntos
Insuficiência Cardíaca , Proteína 1 Semelhante a Receptor de Interleucina-1 , Humanos , Insuficiência Cardíaca/diagnóstico , Peptídeo Natriurético Encefálico , Prognóstico , Biomarcadores , Limite de Detecção
14.
Micromachines (Basel) ; 15(1)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38258263

RESUMO

DNA microarrays have been applied for comprehensive genotyping, but remain a drawback in complicated operations. As a solution, we previously reported the solid-phase collateral cleavage (SPCC) system based on the clustered regularly interspaced short palindromic repeat/CRISPR-associated protein 12 (CRISPR/Cas12). Surface-immobilized Cas12-CRISPR RNA (crRNA) can directly hybridize target double-stranded DNA (dsDNA) and subsequently produce a signal via the cleavage of single-stranded DNA (ssDNA) reporter immobilized on the same spot. Therefore, SPCC-based multiplex dsDNA detection can be performed easily. This study reports the miniaturization of SPCC-based spots patterned by a non-contact printer and its performance in comprehensive genotyping on a massively accumulated array. Initially, printing, immobilization, and washing processes of Cas12-crRNA were established to fabricate the non-contact-patterned SPCC-based sensor array. A target dsDNA concentration response was obtained based on the developed sensor array, even with a spot diameter of 0.64 ± 0.05 mm. Also, the limit of detection was 572 pM, 531 pM, and 3.04 nM with 40, 20, and 10 nL-printing of Cas12-crRNA, respectively. Furthermore, the sensor array specifically detected three dsDNA sequences in one-pot multiplexing; therefore, the feasibility of comprehensive genotyping was confirmed. These results demonstrate that our technology can be miniaturized as a CRISPR/Cas12-based microarray by using non-contact printing. In the future, the non-contact-patterned SPCC-based sensor array can be applied as an alternative tool to DNA microarrays.

15.
Adv Mater ; 36(4): e2304935, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37589665

RESUMO

Rapid detection of various exosomes is of great significance in early diagnosis and postoperative monitoring of cancers. Here, a divisional optical biochip is reported for multiplex exosome analysis via combining the self-assembly of nanochains and precise surface patterning. Arising from resonance-induced near-field enhancement, the nanochains show distinct color changes after capturing target exosomes for direct visual detection. Then, a series of divisional nanochain-based biochips conjugated with several specific antibodies are fabricated through designed hydrophilic and hydrophobic patterns. Because of the significant wettability difference, one sample droplet is precisely self-splitting into several microdroplets enabling simultaneous identification of multiple target exosomes in 30 min with a sensitivity of 6 × 107 particles mL-1 , which is about two orders lower than enzyme-linked immunosorbent assay. Apart from the trace amount detection, excellent semiquantitative capability is demonstrated to distinguish clinical exosomes from glioblastoma patients and healthy people. This method is simple, versatile, and highly efficient that can be extended as a diagnostic tool for many diseases, promoting the development of liquid biopsy.


Assuntos
Exossomos , Humanos , Exossomos/química , Sistemas Automatizados de Assistência Junto ao Leito , Molhabilidade , Interações Hidrofóbicas e Hidrofílicas , Anticorpos
16.
J Colloid Interface Sci ; 657: 580-589, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38071807

RESUMO

All-inorganic lead halide perovskite nanocrystals exhibiting bright luminescence have great potential as fluorescence elements for optical encoding. However, their limited stability in water hinders the application in biosensing. In this study, novel optical encoded microbeads based on CsPbX3 (X = Cl, Br) nanocrystals are developed and applied in bead-based suspension arrays for the first time. Through the in-situ crystallization of CsPbX3 nanocrystals within mesoporous silica nano-templates (MSNs), accompanied by mesopores collapse after sintering, CsPbX3@MSNs (X3M) nanocomposites with uniform morphology and stable fluorescence intensity in aqueous solutions for up to 50 days are obtained. By assembling X3M with microspheres to form a host-guest structure, an optical encoding microbead (MX3M) library is established by varying the X3M ratio, halide composition, and the size of host microspheres, which can be easily decoded under multi-channel flow cytometer. As a result, MX3M exhibits outstanding capacity for specific target capture and negligible nonspecific absorption performance in the multiplex nucleic acid detection of respiratory viruses, with a low limit of detection (10 copies/rxn). This result highlights the tremendous potential of MX3M encoded microbeads constructed based on CsPbX3 nanocrystals for multiplexed bioassays.

17.
Biosens Bioelectron ; 247: 115927, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38113694

RESUMO

MicroRNAs (miRNAs) are increasingly recognized as promising biomarkers for early disease diagnosis and prognosis. Therefore, the need for rapid, robust methods for multiplex miRNA detection in biological research and clinical diagnosis is crucial. This study introduces a novel multiplex miRNA detection method, SMOS-qPCR (Sensitive and Multiplexed One-Step RT-qPCR). The method integrates multiplexed reverse transcription and TaqMan-based qPCR into a single tube, employing a one-step operation on a real-time PCR system. We investigated the effect of 3' end phosphorylation of the Linker, Linker concentration and probe concentration on the SMOS-qPCR, resulted in a wide linear range from 1 fM to 0.1 zM (R2 ≥ 0.99 for each miRNA), surpassing the capabilities of stem-loop RT-qPCR and SYBR Green One-step RT-qPCR. The method showed excellent performance in distinguishing mature miRNA from miRNA precursor, and successfully detected four miRNAs in a single tube without cross-interference. Its high specificity enables precise differentiation of less than 1% nonspecific signal. Finally, we demonstrated the effectiveness of the SMOS-qPCR system in detecting circulating miRNAs in serum samples, distinguishing between esophageal cancers and health individuals with high AUC values (>0.940). In conclusion, the proposed SMOS-qPCR system offers a straightforward and promising approach for miRNA profiling in future clinical applications.


Assuntos
Técnicas Biossensoriais , MicroRNA Circulante , Neoplasias Esofágicas , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/análise , Reação em Cadeia da Polimerase em Tempo Real/métodos , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/genética
18.
Sci Total Environ ; 912: 169440, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38123096

RESUMO

The co-contamination of pesticide residues and mycotoxins in agricultural products is a global concern, with the potential for cumulative and synergistic damaging effects, imposing substantial health and economic burdens to the public. The dosage-sensitive and simultaneous detection of multiple pollutants, with a heightened sensitivity in real samples, poses a significant demand and challenge. Herein, we propose a portable detection method integrating surface-enhanced Raman scattering (SERS)-with lateral flow immunoassay (LFIA), offering high sensitivity and multiplex analysis capabilities. This approach enables the simultaneous detection of imidacloprid (IMI), pyraclostrobin (PYR) and aflatoxin B1 (AFB1) through a single test strip. Utilizing the immune-specific binding between antigen and antibodies, we immobilised antibody- conjugated SERS nanotags on three test lines of the strips to generate Raman signal amplification in the proposed biosensor. Accurate quantitative analysis was performed by measuring the SERS signal intensity on the test lines. The limits of detection were 8.6 pg/mL for IMI, 97.4 pg/mL for PYR and 8.9 pg/mL for AFB1, exhibiting sensitivities 12-fold, 102-fold and11-fold higher than the colorimetric signals, respectively. Importantly, the SERS-LFIA immunosensor demonstrated robust performance when applied to real samples, yielding recoveries ranging from 86.16 % to 115.0 %, with relative standard deviation values below 8.67 %. These results underscore the excellent stability, high selectivity and reliability the proposed SERS-LFIA immunosensor. Consequently, it holds promise for the detection of multiple pesticides and mycotoxins in both environmental and agricultural samples.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Micotoxinas , Técnicas Biossensoriais/métodos , Reprodutibilidade dos Testes , Imunoensaio/métodos , Anticorpos , Análise Espectral Raman/métodos , Nanopartículas Metálicas/química , Limite de Detecção , Ouro/química
19.
Int J Biol Macromol ; 257(Pt 2): 128773, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38096932

RESUMO

Periodontitis is a chronic inflammation of the periodontium caused by a persistent bacterial infection, resulting in destruction of the supporting structures of teeth. Analysis of microbial composition in saliva can inform periodontal status. Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and Streptococcus mutans (Sm) are among reported periodontal pathogens, and were used as model systems in this study. Our atomic force microscopic (AFM) study revealed that these pathogens are biological nanorods with dimensions of 0.6-1.1 µm in length and 500-700 nm in width. Current bacterial detection methods often involve complex preparation steps and require labeled reporting motifs. Employing surface-enhanced Raman spectroscopy (SERS), we revealed cell-type specific Raman signatures of these pathogens for label-free detection. It overcame the complexity associated with spectral overlaps among different bacterial species, relying on high signal-to-noise ratio (SNR) spectra carefully collected from pure species samples. To enable simple, rapid, and multiplexed detection, we harnessed advanced machine learning techniques to establish predictive models based on a large set of raw spectra of each bacterial species and their mixtures. Using these models, given a raw spectrum collected from a bacterial suspension, simultaneous identification of all three species in the test sample was achieved at 95.6 % accuracy. This sensing modality can be applied to multiplex detection of a broader range and a larger set of periodontal pathogens, paving the way for hassle-free detection of oral bacteria in saliva with little to no sample preparation.


Assuntos
Periodontite , Análise Espectral Raman , Humanos , Periodontite/microbiologia , Porphyromonas gingivalis , Periodonto , Saliva
20.
Small ; : e2308424, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38081800

RESUMO

The rapid, simultaneous, and accurate identification of multiple non-nucleic acid targets in clinical or food samples at room temperature is essential for public health. Argonautes (Agos) are guided, programmable, target-activated, next-generation nucleic acid endonucleases that could realize one-pot and multiplexed detection using a single enzyme, which cannot be achieved with CRISPR/Cas. However, currently reported thermophilic Ago-based multi-detection sensors are mainly employed in the detection of nucleic acids. Herein, this work proposes a Mesophilic Argonaute Report-based single millimeter Polystyrene Sphere (MARPS) multiplex detection platform for the simultaneous analysis of non-nucleic acid targets. The aptamer is utilized as the recognition element, and a single millimeter-sized polystyrene sphere (PSmm ) with a large concentration of guide DNA on the surface served as the microreactor. These are combined with precise Clostridium butyricum Ago (CbAgo) cleavage and exonuclease I (Exo I) signal amplification to achieve the efficient and sensitive recognition of non-nucleic acid targets, such as mycotoxins (<60 pg mL-1 ) and pathogenic bacteria (<102 cfu mL-1 ). The novel MARPS platform is the first to use mesophilic Agos for the multiplex detection of non-nucleic acid targets, overcoming the limitations of CRISPR/Cas in this regard and representing a major advancement in non-nucleic acid target detection using a gene-editing-based system.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...