Fabrication of Flexible Aunps@ Polyimide Sers Heating Chips for in Situ Highly Sensitive Explosives Sensing in Nature Samples

Abstract

The in situ detection of target molecules from complex environment is a very difficult challenge. We described here highly sensitive AuNPs@ polyimide SERS heating chips (APHC) with specific response for in situ collecting and detecting TNT. Firstly, polyimide film interspersed with heating system was prepared. Then, large-scale of AuNPs arrays were fabricated and transferred on polyimide heating film by liquid-liquid interface self-assembly. Because homogeneous "hot spot" structure of AuNPs on APHC, highly sensitivity and reproducibility was evaluated by probe crystal violet (CV). Next, 4-ATP and AgNPs functionalized on APHC were used as trapping means and signal amplifiers, combining with TNT to form AuNPs-TNT-AgNPs "sandwich" structure for achieving highly specific reaction to TNT. Regarding the Meisenheimer mechanism from "sandwich" structure, this SERS chip could detect TNT solutions with a low concentration of 10-9 M. Combing with thermal enrichment strategy, TNT dispersed in environmental samples such as soil, fruit and clothing will be enriched as vapor then collected by APHC device. These further applications to in situ sensing TNT in complex environment also complied with good recoveries and sensitivity. This APHC device shows great potential for in situ sensing platforms, due to its sensitivity, high efficiency, and excellent portability.

Keywords: SERS chips, self-assemble, explosive TNT, target molecules enrichment, in situ detection