1. Nanobody-based fluorescent immunoassay using carbon dots anchored cobalt oxyhydroxide composite for the sensitive detection of fenitrothion.
- Author
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Luo L, Lin SQ, Wu ZY, Wang H, Chen ZJ, Deng H, Shen YD, Zhang WF, Lei HT, and Xu ZL
- Subjects
- Alkaline Phosphatase chemistry, Cobalt, Humans, Immunoassay, Oxides, Tandem Mass Spectrometry, Carbon chemistry, Fenitrothion
- Abstract
Fenitrothion (FN) residue in food is a serious threat to public health. Consequently, a sensitive, cost-effective, and convenient immunoassay for FN urgently needs to be fabricated to safeguard human health. Herein, a nanobody-alkaline phosphatase fusion protein (Nb-ALP)-based fluorescent ELISA using red emissive carbon dots (r-CDs) anchored cobalt oxyhydroxide nanosheet (CoOOH NS) composite was developed for detecting FN. Briefly, a Nb-ALP was obtained by autoinduction expression and employed as a recognition, signal transduction, and amplification element. As the fluorescence signal source, r-CDs were assembled with CoOOH NS to yield the r-CDs@CoOOH NS composite, leading to the fluorescence quenching of r-CDs via Förster resonance energy transfer (FRET). After competitive immunoreaction, the Nb-ALP bounded to the immobilized antigen can mediate the production of ascorbic acid, which can reduce the CoOOH NS to Co
2+ , breaking the FRET between r-CDs and CoOOH NS, accompanied by the fluorescence recovery of r-CDs. This fluorescent ELISA is highly sensitive to FN with a detection limit of 0.14 ng mL-1 , which is 25-fold lower than that of conventional colorimetric ELISAs. The recovery test of food samples and the validation by GC-MS/MS further demonstrated the proposed assay was an ideal tool for detecting FN., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)- Published
- 2022
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