Development of a Rapid Gold Nanoflowers Immunochromatographic Test Strip Based on the Nanobody for Detection of Aflatoxin B₁

Abstract

A rapid gold nanoflowers (AuNFs) immunochromatographic test strip (ICTS) based on the nanobody (Nb) was developed and used for rapid detection of Aflatoxin B1 (AFB1). Thanks to remarkable physicochemical stability, structural adaptability, ease of genetic manipulation, expression in the prokaryotic system with high yield and tolerance to harsh environments of nanobodies, the G8‐DIG was produced via expression and purification, which was labeled with AuNFs by electrostatic adsorption as signal probes in the ICTS. The AuNFs‐anti‐G8‐DIG nanobodies as a probe of ICTS could specifically recognize not only AFB1 but also DIG‐BSA. In this study, the DIG‐BSA replaced the anti‐6×His‐tag antibody of traditional nanobody‐based ICTS was coated on the control line, which was easier to synthesize, cheaper, and more stable. Under the optimal conditions, the AuNFs‐based nanobody ICTS system accurately detected AFB1 linearly and dynamically over the range (IC20~IC80) of 1.02~27.86 ng/mL, with the IC10 and IC50 of 0.1 ng/mL and 5.46 ng/mL respectively. In addition, these developed nanobodies ICTS had a universal application in the analysis of AFB1 in corn samples.