A simple colorimetric immunoassay for quantitative monitoring of brevetoxin B on a functionalized magnetic bead by using glucose oxidase (GOx)/antibrevetoxin antibody-labeled gold nanoparticle as the signal transduction tag was developed. The assay was carried out on the basis of GOx-controlled sulfite-to-sulfate chemical conversion with a silver(I)-3,3',5,5'-tetramethylbenzidine [Ag(I)-TMB] system. Initially, the sulfite was used as an inhibitor of Ag(I) to hinder the color development of TMB due to the formation of insoluble silver sulfite. Accompanying H2O2 generation with GOx-catalyzed glucose, the sulfite was converted into the sulfate, thus resulting in the colorless-to-blue change. Under the optimal conditions, the absorbance decreased with increasing brevetoxin B from 0.5 to 200 ng/kg with a detection limit of 0.1 ng/kg (ppt). The precision and specificity were acceptable. Furthermore, the methodology gave results matching well with the referenced brevetoxin ELISA kit for monitoring of spiked Musculista senhousia samples.
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http://dx.doi.org/10.1021/acs.jafc.5b00425 | DOI Listing |
Biosens Bioelectron
December 2024
School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315200, China. Electronic address:
Routine screening for cardiovascular diseases (CVDs) through point-of-care assays for at-home or community-based testing of salivary biomarkers can significantly improve patient outcomes. However, its translatability has been hindered by a dearth of biosensing devices that streamline assay procedures for rapid biomarker quantitation. To address this challenge through end-to-end engineering, we developed an in-house, all-in-one microfluidic immunosensing device that integrates on-chip vibration-enhanced incubation, magnetic-assisted separation using immune magnetic bead probes, and colorimetric readout via absorbance measurements.
View Article and Find Full Text PDFBiosensors (Basel)
December 2024
Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, 119991 Moscow, Russia.
A novel approach to developing lateral flow assays (LFAs) for the detection of CYFRA 21-1 (cytokeratin 19 fragment, a molecular biomarker for epithelial-origin cancers) is proposed. Magnetic bioconjugates (MBCs) were employed in combination with advanced optical and magnetic tools to optimize assay conditions. The approach integrates such techniques as label-free spectral-phase interferometry, colorimetric detection, and ultrasensitive magnetometry using the magnetic particle quantification (MPQ) technique.
View Article and Find Full Text PDFBiosensors (Basel)
December 2024
Henan Province Key Laboratory of New Opto-Electronic Functional Materials, College of Chemistry and Chemical Engineering, Anyang Normal University, Anyang 455000, China.
Nanomaterials have attracted significant attention as signal reporters for immunoassays. They can directly generate detectable signals or release a large number of signaling elements for readout. Among various nanolabels, nanomaterials composed of multiple signaling molecules have shown great potential in immunoassays.
View Article and Find Full Text PDFTalanta
December 2024
Marshall Laboratory of Biomedical Engineering, Shenzhen Key Laboratory for Nano-Biosensing Technology, Department of Biomedical Engineering, Medical School, Shenzhen University, Shenzhen, Guangdong, 518060, PR China. Electronic address:
Colorimetric enzyme-linked immunosorbent assays (CELISAs) have long been used for protein biomarker detection in diagnostics. Unfortunately, as confined by the monochromatic nature of detection signals and the limited catalytic activity of enzymes, CELISAs suffer from poor visual resolution and low sensitivity, hindering their effectiveness for early diagnostics in resource-limited settings. Herein, we report an ultrasensitive, high-visual-resolution CELISA (named PE-TSA-AuAg Cage-CELISA) that combines kinetically controlled growth of Ag in AuAg nanocages with poly-enzyme-boosted tyramide signal amplification (PE-TSA), enabling visual semiquantitative detection of protein biomarkers at attomolar levels with the naked eye.
View Article and Find Full Text PDFFood Chem
December 2024
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, PR China; College of Food Engineering, Ludong University, Yantai, 264025, Shandong, PR China. Electronic address:
Fully excavating and utilizing the rich information presented on bacterial surfaces can open innovative solutions for the multi-mechanism detection of food-borne pathogens. In this work, a colorimetric-fluorescence dual-signal lateral flow immunoassay was used to establish a simultaneous detection strategy integrating five physical, chemical, and biometric combining mechanisms for Salmonella typhimurium (S. typhimurium) and Staphylococcus aureus (S.
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