A one-piece lateral flow impedimetric test strip for label-free clenbuterol detection

Abstract

A one-piece lateral flow impedimetric test was developed for detection of clenbuterol hydrochloride, a restricted food additive. The immunochromatograph strip was sandwiched between microelectrodes patterned on a thin poly(ethylene terephthalate) (PET) film. To demonstrate the label-free assay capability of the electrode/lateral flow impedimetric test, a polyaniline@graphene oxide (PANI@GO) nanocomposite was synthesized to functionalize the sensing electrode. The morphology, chemical functional group and electrochemical stability of the synthesized polyaniline/graphene oxide nanocomposite were characterized by field emission scan electron microscopy (FESEM), Fourier transform infrared (FTIR), and electrochemical impedance spectroscopy (EIS). The fully assembled one-piece lateral flow impedimetric tests were successfully applied for detection of clenbuterol hydrochloride (CLH) with a working range of 0.12–58 ppb and a lower detection limit of 0.12 ppb, demonstrating a universal method to label-free, sensitive detection of small target molecules by a portable strip for applications in food safety.