Graphene oxide functionalized halloysite nanotubes for voltammetric determination of psychoactive drug from alcoholic and non-alcoholic drinks

Abstract

In context to the widespread misuse of benzodiazepines, a novel platform based on the graphene oxide functionalized halloysite nanotubes (HNT/GO) has been introduced for the electrochemical detection of commonly abused date rape drug-nitrazepam (NZP). In this work, HNT/GO composite has been synthesized via simple stirring method and the fabricated materials were characterized by using combination of spectroscopic, microscopic, X-ray and voltammetric techniques i.e., FTIR, FE-SEM-EDX, TEM, XRD, XPS and Cyclic voltammetry. Surface modification of HNTs with GO increased the synergistic properties of both the materials for electrochemical sensing of nitrazepam. Specifically, HNTs provided high surface area, nanotubular morphology with unique surface functionalities and GO added electron rich functional sites. Combination of HNTs with GO significantly increased electrochemical active surface area from 0.06 to 0.236 cm² which increased electron transfer on the surface of electrode towards electrochemical reduction of nitrazepam. The developed sensor showed excellent electrochemical response for nitrazepam detection with a linear dynamic range of 0.16–150 μM and limit of detection 0.79 μM. The proposed sensor has successfully been employed for electrochemical determination of nitrazepam in non-alcoholic and alcoholic drinks without any sample pre-treatment.