Fluorometric lateral flow immunochromatographic zearalenone assay by exploiting a quencher system composed of carbon dots and silver nanoparticles

Abstract

It is found that the fluorescence of carbon dots (CD) with an emission peak at 459 nm is strongly quenched by silver nanoparticles (AgNPs) with their absorption peak at 430 nm. The finding was applied in a fluorescence quenchometric lateral flow immunochromatographic assay for detection of zearalenone (ZEN) with CDs conjugated to ovalbumin (OVA) as donor signal probe and AgNP-Ab as acceptor signal probe. The assay has an LOD of 0.1 μg·L for ZEN. This is 10 times better than the respective "turn-off" AgNP-based LFIA. In case of cereal samples and their products, the LODs range from 1 to 2.5 μg·kg. Only minor cross reactivity is found for fusarium toxins, and no cross-sensitivity for aflatoxin B1, T-2 mycotoxin, ochratoxin A, deoxynivalenol, and fumonisin B1. The assay represents a simple, sensitive, and rapid tool for determination of ZEN in cereal samples and their products. Graphical abstract Schematic presentation of fluorescence quenching lateral flow immunochromatographic assay (FLFIA) based on carbon dots (CD) and silver nanoparticle (AgNP) fluorescence resonance energy transfer (FRET) system for the rapid high sensitive detection of zearalenone (ZEN) in cereal samples.

A review on advances in methods for modification of paper supports for use in point-of-care testing

“…Besides the above mentioned paper materials, various types of nanomaterials, such as carbon dots (CD) [110,111], silver nanoparticles (AgNP) [41], AuNPs [38,39,43,112,113] and AuNPs@SiO 2 NPs [25] and other nanomaterials [48,50,55], have also been used as detection probes to generate colorimetric signals on the test strips of LFAs ( Table 2). The nanoparticles on LFAs are modified with different biomolecules (e.g., antibody), which can immobilize on conjugation pad and interact with target and then bind the biomolecules on test line for detection.…”

“…A wax-based technology was applied to modify hydrophobic patterns and hydrophobic barriers on paper using a wax printer [27] and a pen-writing approach [28]. Different nanomaterials, such as quantum dots (QDs) [29][30][31][32][33], gold nanoparticles (AuNPs) [24,[34][35][36][37][38][39][40][41][42][43][44][45][46], AuNFs MBA @Ag [47] Cu-Pd/rGO nanoparticles [48], upconverting fluorescent nanocrystals [49], metal-organic framework [50], fluorescent nanoparticles [51], gold nanocage [52], gold nanorods [53], multi-walled carbon nanotubes and graphene oxide [54] and polymer nanoparticles [55], have also been used as reading signal in paper-based POCT devices. The functional papers prepared by these advanced modification approaches significantly extend the application potential of paper as the substrate of POCT devices.…”

Point-of-care diagnostics for infectious diseases: From methods to devices

“…The fluorescence signals are proportional to the target amounts. Except for traditional fluorescent dyes, some nanomaterials have also been widely employed for developing fluorescence biosensors due to their excellent fluorescence properties, such as quantum dots (QDs) [133] , carbon dots (CDs) [134] , [135] , upconversion nanoparticles (UCNPs) [136] , and metal nanoclusters (NCs) [137] , [138] , [139] , which have been widely applied for the fabrication of fluorescence biosensors. Herein, various direct fluorescence labeling biosensors for POC diagnostics of infectious diseases were summarized.…”

Recent advances in immunoassays and biosensors for mycotoxins detection in feedstuffs and foods

“…Carbon dots were conjugated to ovalbumin as the donor signal probe and AgNPs-Antibody served as the acceptor signal probe. The LOD of the LFIA was 10 times better than the “turn-off” AgNPs-based LFIA [ 63 ].…”