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

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• 作者：Meiling Ren ; Hengyi Xu ; Xiaolin Huang ; Min Kuang ; Yonghua Xiong ; Hong Xu ; Yang Xu ; Hongyu Chen ; Andrew Wang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：August 27, 2014
• 年：2014
• 卷：6
• 期：16
• 页码：14215-14222
• 全文大小：415K
• ISSN：1944-8252

文摘

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^鈥?, with a median inhibitory concentration (IC₅₀) of 13.87 卤 0.16 pg mL^鈥?, that is significantly (39-fold) lower than those of the QD as a signal probe (IC₅₀ = 0.54 卤 0.06 ng mL^鈥?). The limit of detection (LOD) for AFB₁ using QB-ICA sensor was 0.42 pg mL^鈥? 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鈥揗S/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.

Keywords:

quantum dot; beads; immunochromatographic assay; quantitative detection; aflatoxin B₁