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1.
Anal Chem ; 96(12): 5046-5055, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38488055

RESUMO

Bimodal-type multiplexed immunoassays with complementary mode-based correlation analysis are gaining increasing attention for enhancing the practicability of the lateral flow immunoassay (LFIA). Nonetheless, the restriction in visually indistinguishable multitargets induced by a single fluorescent color and difficulty in single acceptor ineffectual fluorescence quenching due to the various spectra of multiple different donors impede the further execution of colorimetric-fluorescence bimodal-type multiplexed LFIAs. Herein, the precise spectral overlap-based donor-acceptor pair construction strategy is proposed by regulating the size of the nanocore, coating it with an appropriate nanoshell, and selecting a suitable fluorescence donor with distinct colors. By in situ coating Prussian blue nanoparticles (PBNPs) on AuNPs with a tunable size and absorption spectrum, the resultant APNPs demonstrate efficient fluorescence quenching ability, higher colloidal stability, remarkable colorimetric intensity, and an enhanced antibody coupling efficiency, all of which facilitate highly sensitive bimodal-type LFIA analysis. Following integration with competitive-type immunoreaction, this precise spectral overlap-supported spatial separation traffic light-typed colorimetric-fluorescence dual-response assay (coined as the STCFD assay) with the limits of detection of 0.013 and 0.152 ng mL-1 for ractopamine and clenbuterol, respectively, was proposed. This work illustrates the superiority of the rational design of a precise spectral overlap-based donor-acceptor pair, hinting at the enormous potential of the STCFD assay in the point-of-care field.


Assuntos
Clembuterol , Nanopartículas Metálicas , Ouro , Imunoensaio , Fenômenos Químicos , Limite de Detecção
2.
Lab Chip ; 24(8): 2272-2279, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38504660

RESUMO

A highly sensitive lateral flow immunoassay (LFIA) is developed for the enzyme-catalyzed and double-reading determination of clenbuterol (CLE), in which a new type of probe was adopted through the direct electrostatic adsorption of ultra-small copper-gold bimetallic enzyme mimics (USCGs) and monoclonal antibodies. In the assay, based on the peroxidase activity of USCG, the chromogenic substrate TMB-H2O2 was introduced to trigger its color development, and the results were compared with those before catalysis. The detection sensitivity after catalysis is 0.03 ng mL-1 under optimal circumstances, which is 6-fold better than that of the traditional Au NPs-based LFIA and 2-fold greater than that before catalysis. This approach was successfully applied to the detection of CLE in milk, pork and mutton samples with an optimum assay time of 7 min and best catalytic time of 80 s, after which satisfactory recoveries of 98.53-117.79% were obtained. Cu-Au nanoparticles as a signal tag and the use of their nanozyme properties are the first applications in the field of LFIA. This work can be a promising exhibition for the application of a cheaper substitute for HRP, ultra-small bimetallic enzyme mimics, in LFIAs.


Assuntos
Clembuterol , Nanopartículas Metálicas , Limite de Detecção , Cobre , Ouro/química , Peróxido de Hidrogênio , Nanopartículas Metálicas/química , Catálise , Imunoensaio/métodos
3.
MedComm (2020) ; 5(2): e494, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38405059

RESUMO

Lung tissue has a certain regenerative ability and triggers repair procedures after injury. Under controllable conditions, lung tissue can restore normal structure and function. Disruptions in this process can lead to respiratory system failure and even death, causing substantial medical burden. The main types of respiratory diseases are chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and acute respiratory distress syndrome (ARDS). Multiple cells, such as lung epithelial cells, endothelial cells, fibroblasts, and immune cells, are involved in regulating the repair process after lung injury. Although the mechanism that regulates the process of lung repair has not been fully elucidated, clinical trials targeting different cells and signaling pathways have achieved some therapeutic effects in different respiratory diseases. In this review, we provide an overview of the cell type involved in the process of lung regeneration and repair, research models, and summarize molecular mechanisms involved in the regulation of lung regeneration and fibrosis. Moreover, we discuss the current clinical trials of stem cell therapy and pharmacological strategies for COPD, IPF, and ARDS treatment. This review provides a reference for further research on the molecular and cellular mechanisms of lung regeneration, drug development, and clinical trials.

4.
Eur J Med Chem ; 267: 116203, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38342014

RESUMO

BACKGROUND: Quercetin is widely distributed in nature and abundant in the human diet, which exhibits diverse biological activities and potential medical benefits. However, there remains a lack of comprehensive understanding about its cellular targets, impeding its in-depth mechanistic studies and clinical applications. PURPOSE: This study aimed to profile protein targets of quercetin at the proteome level. METHODS: A label-free CETSA-MS proteomics technique was employed for target enrichment and identification. The R package Inflect was used for melting curve fitting and target selection. D3Pocket and LiBiSco tools were used for binding pocket prediction and binding pocket analysis. Western blotting, molecular docking, site-directed mutagenesis and pull-down assays were used for target verification and validation. RESULTS: We curated a library of direct binding targets of quercetin in cells. This library comprises 37 proteins that show increased thermal stability upon quercetin binding and 33 proteins that display decreased thermal stability. Through Western blotting, molecular docking, site-directed mutagenesis and pull-down assays, we validated CBR1 and GSK3A from the stabilized protein group and MAPK1 from the destabilized group as direct binding targets of quercetin. Moreover, we characterized the shared chemical properties of the binding pockets of quercetin with targets. CONCLUSION: Our findings deepen our understanding of the proteins pivotal to the bioactivity of quercetin and lay the groundwork for further exploration into its mechanisms of action and potential clinical applications.


Assuntos
Proteoma , Quercetina , Humanos , Quercetina/farmacologia , Quercetina/química , Simulação de Acoplamento Molecular , Proteoma/metabolismo , Espectrometria de Massas
5.
Food Chem ; 441: 138374, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38219366

RESUMO

In this work, an ultra-sensitive lateral flow immunoassay (LFIA) with SERS/colorimetric dual signal mode was constructed for the detection of nitrofurazone metabolites, an antibiotic prohibited in animal-origin foods. Au@4-MBN@AgNRs nano-sandwich structural signal tag integrates the unique advantages of high signal-to-background ratio and anti-matrix interference through geometric control of SERS tag and nanoengineering adjustment of chemical composition. Under the optimal conditions, the detection limits of nitrofurazone metabolites by SERS/colorimetric dual-mode LFIA were 20 pg/mL (colorimetric mode) and 0.08 pg/mL (SERS mode). Excitingly, the vLOD of the colorimetric signal improved by a factor of 100 compared to Au NPs-based LFIA. In this study, the proposed dual-mode LFIA was successfully applied to the on-site real-time detection of honey, milk powder, and chicken. It is anticipated that with low background interference and anti-matrix interference output signal, our proposed dual-mode strategy can pave an innovative pathway for the fabrication of a powerful biosensor.


Assuntos
Nanopartículas Metálicas , Nitrofurazona , Animais , Ouro/química , Imunoensaio , Antibacterianos , Colorimetria , Nanopartículas Metálicas/química , Limite de Detecção , Análise Espectral Raman
6.
Epigenetics ; 19(1): 2299044, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38154055

RESUMO

Early detection of hepatocellular carcinoma (HCC) can greatly improve the survival rate of patients. We aimed to develop a novel marker panel based on cell-free DNA (cfDNA) methylation for the detection of HCC. The differentially methylated CpG sites (DMCs) specific for HCC blood diagnosis were selected from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, then validated by the whole genome bisulphite sequencing (WGBS) of 12 paired HCC and paracancerous tissues. The clinical performance of the panel was evaluated using tissue samples [32 HCC, chronic liver disease (CLD), and healthy individuals] and plasma cohorts (173 HCC, 199 CLD, and 98 healthy individuals). The combination of G protein subunit beta 4 (GNB4) and Riplet had the optimal area under the curve (AUC) in seven candidates through TCGA, GEO, and WGBS analyses. In tissue validation, the GNB4 and Riplet showed an AUC of 100% with a sensitivity and specificity of 100% for detecting any-stage HCC. In plasma, it demonstrated a high sensitivity of 84.39% at 91.92% specificity, with an AUC of 92.51% for detecting any-stage HCC. The dual-marker panel had a higher sensitivity of 78.26% for stage I HCC than alpha-fetoprotein (AFP) of 47.83%, and a high sensitivity of 70.27% for detecting a single tumour (size ≤3 cm). In conclusion, we developed a novel dual-marker panel that demonstrates high accuracy in detecting HCC, surpassing the performance of AFP testing.


Assuntos
Carcinoma Hepatocelular , Subunidades beta da Proteína de Ligação ao GTP , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Biomarcadores Tumorais/metabolismo , Metilação de DNA , Subunidades beta da Proteína de Ligação ao GTP/genética , Subunidades beta da Proteína de Ligação ao GTP/metabolismo
7.
Anal Chem ; 95(46): 16958-16966, 2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-37942854

RESUMO

Developing signal tracers (STAs) with large size, multifunctionality, and high retention bioaffinity is believed to be a potential solution for achieving high-performance immunochromatographic assays (ICAs). However, the size limitations of STAs on strips are always a challenge because of the serious steric hindrance. Here, based on metal-quinone coordination and further metal etching, hollow micron-tubular STAs formed by natural alizarin and Fe3+ ions (named ALIFe) are produced to break through size limitations, provide more active sites, and achieve three-mode ICAs (ALIFe STAs-ICAs). Thanks to the special tubular morphology, ALIFe can successfully pass through the strip and provide an ideal signal intensity within 7 min at low mAb and probe dosages to achieve stable ICA analysis. Importantly, ALIFe shows excellent antibody enrichment and bioaffinity retention capability. With a proof-of-concept for streptomycin, the ALIFe STAs-ICAs showed the limit of detection (LOD) at 0.39 ng mL-1 for colorimetric mode, 0.32 ng mL-1 for catalytic mode, and 0.016 ng mL-1 for photothermal mode with total recoveries ranging from 80.46 to 121.59% in mike and honey samples. We anticipate that our study will help expand the ideas for the design of high-performance STAs with large size and broaden the practical application of ICA.


Assuntos
Antibacterianos , Nanopartículas Metálicas , Cromatografia de Afinidade/métodos , Limite de Detecção , Nanopartículas Metálicas/química
8.
Polymers (Basel) ; 15(22)2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-38006069

RESUMO

The introduction of polar functional groups into polyolefin chain structures creates opportunities to enhance specific properties, such as adhesion, dyeability, printability, compatibility, thermal stability, and electrical conductivity, which widen the range of potential applications for these modified materials. Transition metal catalysts, especially late transition metals, have proven to be highly effective in copolymerization processes due to their reduced Lewis acidity and electrophilicity. However, when compared to the significant progress and summary of synthetic methods, there is a distinct lack of a comprehensive summary of mechanistic studies pertaining to the catalytic systems involved in ethylene copolymerization catalyzed by palladium and nickel catalysts. In this review, we have provided a comprehensive summary of the latest developments in mechanistic studies of ethylene copolymerization with polar monomers catalyzed by late-transition-metal complexes. Experimental and computational methods were employed to conduct a detailed investigation of these organic and organometallic systems. It is mainly focused on ligand substitution, changes in binding modes, ethylene/polar monomer insertion, chelate opening, and ß-H elimination. Factors that control the catalytic activity, molecular weight, comonomer incorporation ratios, and branch content are analyzed, these include steric repulsions between ligands and monomers, electronic effects arising from both ligands and monomers, and so on.

9.
Nano Lett ; 23(20): 9563-9570, 2023 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-37819937

RESUMO

Traditional disposable personal protective equipment (PPE) only blocks pathogenic bacteria by mechanical filtration, with the risk of recontamination and transmission remaining. Herein, inspired by phenolic-enabled nanotechnology (PEN), we proposed engineered polyphenol coatings by plant-derived aromatic aldehydes and metal involvement, denoted as FQM, to obtain the desired photocatalysis-self-Fenton antibacterial performance. Experiments and theoretical analysis proved the dual mechanism of Fe-induced enhancement: (1) tuning of molecular structure realized improved optical properties; (2) Fe(III)/Fe(II) triggered photocatalytic cascade self-Fenton reaction. Mechanism study reveals FQM killing bacteria by direct-contact ROS attack and gene regulation. Further, the FQM was developed as the ideal antibacterial coating on different fabrics (cloth cotton, polyester, and N95 mask), killing more than 93% of bacteria after 5 cycles of use. Such photocatalysis-self-Fenton coatings based on engineered polyphenols endowed with desirable safety, sustainability, and efficient antibacterial features are promising solutions to meet the challenges of the currently available PPE.


Assuntos
Compostos Férricos , Polifenóis , Polifenóis/farmacologia , Polifenóis/química , Têxteis , Antibacterianos/farmacologia , Antibacterianos/química
10.
Int J Gynecol Pathol ; 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37732995

RESUMO

Loss of estrogen receptor/progesterone receptor (ER/PR) in endometrial cancer (EC) is associated with tumor progression and poor outcomes. Elevated pretreatment cancer antigen 125 (CA 125) level is a risk factor for lymph node metastasis (LNM). We evaluated whether the combination of ER/PR expression and CA 125 level could be used as a biomarker to predict LNM. We retrospectively investigated patients with endometrioid EC who underwent complete staging surgery during January 2015 to December 2020. We analyzed ER/PR status using immunohistochemical staining, and quantified its expression using the sum of both ER/PR H-scores. Receiver operating characteristic curves were used to identify optimal cutoff values of H-score and CA 125 levels for predicting LNM. A nomogram for predicting LNM was constructed and validated by bootstrap resampling. In 396 patients, the optimal cutoff values of the ER/PR H-score and CA 125 were 407 (area under the receiver operating characteristic curve: 0.645, P=0.001) and 40 U/mL (area under the receiver operating characteristic curve: 0.762, P<0.001), respectively. Multivariate analysis showed that CA 125 ≥40 UmL (odds ratio: 10.02; 95% CI: 4.74-21.18) and ER/PR H-score <407 (odds ratio: 4.20; 95% CI: 1.55-11.32) were independent predictors. An LNM predictive nomogram was constructed using these 2 variables and our model yielded a negative predictive value and negative likelihood ratio of 98.3% and 0.14, respectively. ER/PR expression with pretreatment CA 125 levels can help estimate LNM risk and aid in decision-making regarding the need for lymphadenectomy in patients with endometrioid EC.

11.
NPJ Biofilms Microbiomes ; 9(1): 63, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37679355

RESUMO

Bacterial biofilms, which consist of three-dimensional extracellular polymeric substance (EPS), not only function as signaling networks, provide nutritional support, and facilitate surface adhesion, but also serve as a protective shield for the residing bacterial inhabitants against external stress, such as antibiotics, antimicrobials, and host immune responses. Biofilm-associated infections account for 65-80% of all human microbial infections that lead to serious mortality and morbidity. Tremendous effort has been spent to address the problem by developing biofilm-dispersing agents to discharge colonized microbial cells to a more vulnerable planktonic state. Here, we discuss the recent progress of enzymatic eradicating strategies against medical biofilms, with a focus on dispersal mechanisms. Particularly, we review three enzyme classes that have been extensively investigated, namely glycoside hydrolases, proteases, and deoxyribonucleases.


Assuntos
Biofilmes , Matriz Extracelular de Substâncias Poliméricas , Humanos , Antibacterianos , Plâncton , Transdução de Sinais
12.
Eur J Med Chem ; 259: 115704, 2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-37544186

RESUMO

Limonoids, a class of abundant natural tetracyclic triterpenoids, present diverse biological activity and provide a versatile platform amenable by chemical modifications for clinical use. Among all of the limonoids isolated from natural sources, obacunone, nomilin, and limonin are the primary hub of limonoid-based chemical modification research. To date, more than 800 limonoids analogs have been synthesized, some of which possess promising biological activities. This review not only discusses the synthesis of limonoid derivatives as promising therapeutic candidates and details the pharmacological studies of their underlying mechanisms from 2002 to 2022, but also proposes a preliminary limonoid synthetic structure-activity relationship (SAR) and provides future direction of limonoid derivatization research.


Assuntos
Limoninas , Triterpenos , Limoninas/farmacologia , Limoninas/química , Triterpenos/química , Relação Estrutura-Atividade
13.
J Cancer Res Clin Oncol ; 149(13): 11807-11813, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37405474

RESUMO

PURPOSE: To investigate whether the cost-effective, pretreatment tumor markers carcinoembryonic antigen (CEA) and carbohydrate antigen-125 (CA-125) can be used to predict lymph node metastasis (LNM) in endometrioid-type endometrial cancer (EC) and to develop a predictive model. METHODS: This was a single-center retrospective study of patients with endometrioid-type EC who underwent complete staging surgery between January 2015 and June 2022. We identified the optimal cut-off values of CEA and CA-125 for predicting LNM using receiver operating characteristic (ROC) curves. Stepwise multivariate logistic regression analysis was used to identify independent predictors. A nomogram for predicting LNM was constructed and validated by bootstrap resampling. RESULTS: The optimal cut-off values of CEA and CA-125 were 1.4 ng/mL (area under the ROC curve (AUC) 0.62) and 40 U/mL (AUC 0.75), respectively. Multivariate analysis showed that CEA (odds ratio (OR) 1.94; 95% confidence interval (CI) 1.01-3.74) and CA-125 (OR 8.75; 95% CI 4.42-17.31) were independent predictors of LNM. Our nomogram showed adequate discrimination with a concordance index of 0.78. Calibration curves for the probability of LNM showed optimal agreement between the predicted and actual probabilities. The risk of LNM for markers below the cut-offs was 3.6%. The negative predictive value and negative likelihood ratio were 96.6% and 0.26, respectively, with moderate ability to rule out the possibility of LNM. CONCLUSION: We report a cost-effective method of using pretreatment CEA and CA-125 levels to identify patients with endometrioid-type EC who are at a low risk for LNM, which may guide decision-making regarding aborting lymphadenectomy.


Assuntos
Carcinoma Endometrioide , Neoplasias do Endométrio , Feminino , Humanos , Antígeno Carcinoembrionário , Estudos Retrospectivos , Antígeno Ca-125 , Metástase Linfática/patologia , Neoplasias do Endométrio/cirurgia , Neoplasias do Endométrio/patologia , Carcinoma Endometrioide/patologia , Linfonodos/cirurgia , Linfonodos/patologia
14.
Anal Chem ; 95(8): 4095-4103, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36780295

RESUMO

It is of great importance to overcome potential incompatibility problems between dyestuffs and antibodies (mAbs) for extensive commercial application of a dyestuff-chemistry-based ultrafast colorimetric lateral flow immunoassay (cLFIA). Herein, inspired by traditional staining technologies, a basic dyestuff gallocyanine (GC)-assisted biogenic "potential scalpel"-based cLFIA (GC-ABPS-based cLFIA) by employing clenbuterol (CLE) as proof-of-concept was proposed to solve a high degree of incompatibility between the same potential dyestuffs and mAbs. Goat antimouse immunoglobulin (Ab2) could serve as the "potential scalpel" to form the positive potential value biomolecular network self-assemblers (BNSA) with anti-CLE mAbs (AbCLE) by noncovalent force. The cLFIA completed the entire detection process from de novo to detection results within 30 min thanks to the easy availability and ideal marking efficiency (≤1 min, saving 0.4-10 h) of GC. Encouragingly, the proposed ultrafast GC-ABPS-based cLFIA has also exhibited high sensitivity (0.411 ng mL-1) and low cost (300 times) compared with other cLFIAs. Also, the feasibility of the proposed cLFIA was demonstrated by detecting CLE in beef, pork ham, and skim milk. Finally, the proposed GC-ABPS-based cLFIA has broadened the application range of dyestuffs and provided an effective reference strategy for the application of dyestuffs in food safety monitoring.


Assuntos
Clembuterol , Animais , Bovinos , Imunoensaio/métodos , Inocuidade dos Alimentos , Anticorpos Monoclonais
15.
Anal Chem ; 95(7): 3769-3778, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36757057

RESUMO

Expanding sensing modes and improving catalytic performance of nanozyme-based analytical chemistry are beneficial to realizing the desired biosensing of analytes. Herein, Schiff-base chemistry coupled with a novel catechol oxidase-like nanozyme (CHzyme) is designed and constructed, exhibiting two main advantages, including (1) improving catalytic performance by nearly 2-fold compared with only the oxidase-like role of CHzyme; (2) increasing the designability of the output signal by signal transduction of cascade reaction. Thereafter, the substrate sensing modes based on a cascade reaction between the CHzyme-catalyzed reaction and Schiff-base chemistry are proposed and comprehensively studied, containing catalytic substrate sensing mode, competitive substrate sensing mode, and generated substrate sensing mode, expecting to be employed in environmental monitoring, food analyses, and clinical diagnoses, respectively. More meaningfully, the generated substrate sensing mode is successfully applied to construct a cascade reaction coupling ratiometric fluorescent immunoassay for the detection of clenbuterol, increasing 15-fold in detection sensitivity compared with the traditional enzyme-linked immunosorbent assay. It is expected that the expanded universal substrate sensing modes and the Schiff-base chemistry-enhanced nanozyme can enlighten the exploration of innovative biosensors.


Assuntos
Técnicas Biossensoriais , Catecol Oxidase , Ensaio de Imunoadsorção Enzimática
16.
Food Res Int ; 163: 112293, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36596197

RESUMO

Nature-derived chemicals have recently gained increased attention to settle down the challenges in the food industry. Quercetin has long been used as a natural medicine but its photoactivity has been neglected. In this work, by combining photodynamic bacteria inactivation (PDI) with an edible coating (Pectin/Quercetin) derived from FDA-approved chemicals, extend shelf-life and protected commercial quality of fresh-cut apples were achieved. Firstly, the potential photoactivated antibacterial performance of Quercetin (a natural plant flavonoid) was clarified with the treatment of a simulated sunlight lamp, realizing antibacterial efficacy of 100 % towards S. aureus (50 min) and L. monocytogenes (80 min) with light treatment. To develop safe and effective preservation of fresh-cut apples, Pectin/Quercetin edible coatings with 100 µmol/L quercetin were adopted. The results showed that the prepared edible coatings form a protective barrier over the surface of apples, effectively resisting bacterial infection and extending shelf life to 10 days while maintaining good commercial quality (including preferable color, keeping 100 % hardness, 80 % sugar content and 17.3 % weightlessness rate). Therefore, the prepared light-driven Pectin/Quercetin in this work has the potential to develop as fresh-cut fruit preservation technology.


Assuntos
Filmes Comestíveis , Malus , Malus/microbiologia , Conservação de Alimentos/métodos , Quercetina/farmacologia , Staphylococcus aureus , Compostos Fitoquímicos , Pectinas , Antibacterianos
17.
Biosens Bioelectron ; 219: 114807, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36327557

RESUMO

Apart from the obvious benefit of "trash-to-treasure", the acquisition of natural nanomaterials from cheap and renewable waste has been intensively researched because of various bioactivities and physical-chemical features. Herein, for the first time, we employed natural cuttlefish ink nanoparticles (CINPs) as a multifunctional label and designed colorimetric-photothermal dual-mode lateral flow immunoassays (CINPs-mediated CPLFIA) for sensitive detection of clenbuterol (CL). The accessibility and renewability of CINPs overcome barriers that artificial nanomaterials face, such as complex manufacturing and relatively high costs. Additionally, inspired by the mussel adhesion, the bio-affinity of CINPs, such as antibody coupling and preservation, was investigated and showed to be considerably superior to Au NPs, leading to significantly increased immunosensor sensitivity. Meanwhile, CINPs exhibit excellent photothermal conversion efficiency for dual-signal production, avoiding the effect of environmental elements (particularly light) for colorimetric mode. Besides, the biosensor was integrated with a smartphone and a thermal imager for portable sensing. After optimization, the detection limit of CINPs-mediated CPLFIA was 0.179 ng mL-1 (colorimetric mode) and 0.076 ng mL-1 (photothermal mode), which were significantly lower than traditional gold nanoparticles-based LFIA (0.786 ng mL-1). This research attempted to explain the rise in sensitivity. From food waste to food supervision, this research explores the hidden value of natural resources.

18.
Food Chem ; 401: 134140, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108384

RESUMO

Commercial immunochromatographic assay (ICA) is a convenient tool for controlling antibiotic abuse. Although great efforts have been made to improve the detection performance and quantitative capabilities, simplify the manufacturing process of commercial ICA is rarely mentioned. Here, a proof-of-principle work are developed to solve the above problem. Inspired by dyestuff chemistry, we developed an instant immune-network label strategy by dynamic protonation capacity of neutral red (NR), achieving a desirable labeling efficiency (<1min), and applying for ICA detection of chloramphenicol (CAP). Benefits from the efficiently protonation of NR, lengthy probe production time and organic reagents can be avoided, displaying excellent strip production efficiency and detection performance. Eventually, this strategy presents a visual limit of detection (vLOD) at 3 ng/mL, cut-off value is 9 ng/mL. The assay recoveries in milk and honey were 74.45-107.15 %, with the total RSD of 1.62-6.90 %. We envision that this strategy raises the possibility of commercializing of laboratory prototype products.


Assuntos
Antibacterianos , Cloranfenicol , Cloranfenicol/análise , Vermelho Neutro , Cromatografia de Afinidade/métodos , Limite de Detecção , Antibacterianos/análise , Imunoensaio/métodos
19.
FEBS J ; 290(4): 1049-1059, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36083143

RESUMO

Bacterial biofilms consist of bacterial cells embedded within a self-produced extracellular polymeric substance (EPS) composed of exopolysaccharides, extra cellular DNA, proteins and lipids. The enzyme Dispersin B (DspB) is a CAZy type 20 ß-hexosaminidase enzyme that catalyses the hydrolysis of poly-N-acetylglucosamine (PNAG), a major biofilm polysaccharide produced by a wide variety of biofilm-forming bacteria. Native PNAG is partially de-N-acetylated, and the degree of deacetylation varies between species and dependent on the environment. We have previously shown that DspB is able to perform both endo- and exo-glycosidic bond cleavage of PNAG depending on the de-N-acetylation patterns present in the PNAG substrate. Here, we used a combination of synthetic PNAG substrate analogues, site-directed mutagenesis and in vitro biofilm dispersal assay to investigate the molecular basis for the endo-glycosidic cleavage activity of DspB and the importance of this activity for dispersal of PNAG-dependent Staphylococcus epidermidis biofilms. We found that D242 contributes to the endoglycosidase activity of DspB through electrostatic interactions with cationic substrates in the -2 binding site. A DspBD242N mutant was highly deficient in endoglycosidase activity while maintaining exoglycosidase activity. When used to disperse S. epidermidis biofilms, this DspBD242N mutant resulted in an increase in residual biofilm biomass after treatment when compared to wild-type DspB. These results suggest that the de-N-acetylation of PNAG in S. epidermidis biofilms is not uniformly distributed and that the endoglycosidase activity of DspB is required for efficient biofilm dispersal.


Assuntos
Acetilglucosamina , Glicosídeo Hidrolases , Glicosídeo Hidrolases/química , Proteínas de Bactérias/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Eletricidade Estática , Staphylococcus epidermidis/metabolismo , Biofilmes
20.
Compr Rev Food Sci Food Saf ; 21(6): 5077-5108, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36200572

RESUMO

With the rapid growth in global food production, delivery, and consumption, reformative food analytical techniques are required to satisfy the monitoring requirements of speed and high sensitivity. Nanozyme-encoded luminescent detections (NLDs) integrating nanozyme-based rapid detections with luminescent output signals have emerged as powerful methods for food safety monitoring, not only because of their preeminent performance in analysis, such as rapid, facile, low background signal, and ultrasensitive, but also due to their strong attractiveness for future sensing research. However, the lack of a full understanding of the fundamentals of NLDs for food safety detection technologies limits their further application. In this review, a systematic overview of the mechanisms of NLDs and their applications in the food industry is summarized, which covers the nanozyme-mimicking types and their luminescent signal generation mechanisms, as well as their applications in monitoring common foodborne contaminants. As demonstrated by previous studies, NLDs are bridging the gap to practical-oriented food analytical technologies and various opportunities to improve their food analytical performance to be considered in the future are proposed.


Assuntos
Microbiologia de Alimentos , Inocuidade dos Alimentos
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