Quantum-Dot-Bead-Based Fluorescence-Linked Immunosorbent Assay for Sensitive Detection of Cry2A Toxin in Cereals Using Nanobodies.
Yulou QiuAjuan YouXianshu FuMingzhou ZhangHaifeng CuiBiao ZhangWeiwei QinZihong YeXiaoping YuPublished in: Foods (Basel, Switzerland) (2022)
In this study, a quantum-dot-bead (QB)-based fluorescence-linked immunosorbent assay (FLISA) using nanobodies was established for sensitive determination of the Cry2A toxin in cereal. QBs were used as the fluorescent probe and conjugated with a Cry2A polyclonal antibody. An anti-Cry2A nanobody P2 was expressed and used as the capture antibody. The results revealed that the low detection limit of the developed QB-FLISA was 0.41 ng/mL, which had a 19-times higher sensitivity than the traditional colorimetric ELISA. The proposed assay exhibited a high specificity for the Cry2A toxin, and it had no evident cross-reactions with other Cry toxins. The recoveries of Cry2A from the spiked cereal sample ranged from 86.6-117.3%, with a coefficient of variation lower than 9%. Moreover, sample analysis results of the QB-FLISA and commercial ELISA kit correlated well with each other. These results indicated that the developed QB-FLISA provides a potential approach for the sensitive determination of the Cry2A toxin in cereals.
Keyphrases
- sensitive detection
- escherichia coli
- fluorescent probe
- living cells
- high throughput
- loop mediated isothermal amplification
- single molecule
- quantum dots
- gold nanoparticles
- solid phase extraction
- molecularly imprinted
- energy transfer
- monoclonal antibody
- nitric oxide
- photodynamic therapy
- risk assessment
- magnetic resonance imaging
- high resolution
- hydrogen peroxide
- label free
- simultaneous determination
- data analysis
- liquid chromatography