Quartz crystal microbalance sensor based on covalent organic framework composite and molecularly imprinted polymer of poly(o-aminothiophenol) with gold nanoparticles for the determination of aflatoxin B1

In this study, for the first time a quartz crystal microbalance (QCM) sensor based on gold nanoparticles (AuNPs) doped molecularly imprinted layer and covalent organic frameworks composite (COFs-AuNPs) was developed for the detection of aflatoxin B1. The AuNPs doped molecularly imprinted layer involved in the crosslinking of o-aminothiophenol functionalized AuNPs (o-ATP@AuNPs) in the present of the templates on electrode surface. The imprinting recognition sites obtained by eluting the templates from imprinted polymer of poly(o-ATP) with AuNPs formed the specific three-dimensional imprinted contours toward the targets. A kind of porous lightweight material-CTpBD COFs and AuNPs were employed jointly to yield the COFs-AuNPs composite which provided large surface area for o-ATP@AuNPs crosslinking. The introduction of COFs-AuNPs substrate and three-dimensional structure of imprinted matrix endowed the sensor with more recognition sites. The sensitive and selective detection was attributed to the loading capacity of the COFs-AuNPs composite and the specific recognition effect of molecularly imprinted polymer of poly(o-ATP) with AuNPs. Under optimal conditions, the proposed sensor showed a wide linear range from 0.05 to 75 ng mL(-1), low limit of detection (LOD = 2.8 pg mL(-1)) and the acceptable recoveries (87.0% - 101.7%) in real samples analysis.