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Immunochromatographic Assay for Ultrasensitive Detection of Aflatoxin B1 in Maize by Highly Luminescent Quantum Dot Beads

Authors :
Yonghua Xiong
Andrew Y. Wang
Min Kuang
Hong Xu
Yang Xu
Hengyi Xu
Xiaolin Huang
Hongyu Chen
Meiling Ren
Source :
ACS Applied Materials & Interfaces
Publication Year :
2014
Publisher :
American Chemical Society, 2014.

Abstract

Highly luminescent quantum dot beads (QBs) were synthesized by encapsulating CdSe/ZnS and used for the first time as immunochromatographic assay (ICA) signal amplification probe for ultrasensitive detection of aflatoxin B1 (AFB1) in maize. The challenges to using high brightness QBs as probes for ICA are smooth flow of QBs and nonspecific binding on nitrocellulose (NC) membrane, which are overcome by unique polymer encapsulation of quantum dots (QDs) and surface blocking method. Under optimal conditions, the QB-based ICA (QB-ICA) sensor exhibited dynamic linear detection of AFB1 in maize extract from 5 to 60 pg mL(-1), with a median inhibitory concentration (IC50) of 13.87 ± 0.16 pg mL(-1), that is significantly (39-fold) lower than those of the QD as a signal probe (IC50 = 0.54 ± 0.06 ng mL(-1)). The limit of detection (LOD) for AFB1 using QB-ICA sensor was 0.42 pg mL(-1) in maize extract, which is approximately 2 orders of magnitude better than those of previously reported gold nanoparticle based immunochromatographic assay (AuNP-ICA) and is even comparable with or better than the conventional enzyme-linked immunosorbent assay (ELISA) method. The performance and practicability of our QB-ICA sensor were validated with a commercial ELISA kit and further confirmed with liquid chromatography tandem mass spectrometry (LC-MS/MS). Given its efficient signal amplification performance, the proposed QB-ICA offers great potential for rapid, sensitive, and cost-effective quantitative detection of analytes in food safety monitoring.

Details

Language :
English
ISSN :
19448252 and 19448244
Volume :
6
Issue :
16
Database :
OpenAIRE
Journal :
ACS Applied Materials & Interfaces
Accession number :
edsair.doi.dedup.....0c7f098f9bbae276ba2075e5b7586ebd