Facile electrochemical preparation of overoxidizedpolypyrrole/RGO composite for ds-DNA immobilization: a novel signal amplified sensing platform for electrochemical determination of chlorpheniramine.

Abstract

Chlorpheniramine (CPA), thanks to its relatively lower side effects, is a widely prescribed medicine for alleviating allergic symptoms as well as some medical emergencies. Owning to this extensive use, many efforts have been directed to measure chlorpheniramine both in vivo and in vitro. High performance liquid chromatography (HPLC), both normal and reverse phase, as well as spectrochemical and electrochemical methods are analytical approaches which have been extensively exploited for determination of CPA. Among them, electrochemical techniques have found elegant place for analysis of CPA due to simplicity, sensitivity and ease of instrumentation. Herein, we have reported the preparation and characterization of a biosensor by immobilization of double-stranded DNA on the surface of overoxidizedpolypyrrole-reduced graphene oxide modified pencil graphite electrode (ds-DNA-PPyox/RGO/PGE) as well as its novel usability in measurement of chlorpheniramine (CPA). Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), UV-Vis spectroscopy and differential pulse voltammetry (DPV) were exploited in order to characterize and evaluate the performance of the proposed biosensor. Final results showed that proposed strategy for modification of PGE introduces an ultra-sensitive biosensor for CPA which offers the best detection limitamong all previously reported electrochemical sensors for CPA. Taking advantage of this biosensor for determination of CPA, a wide linear dynamic range from 0.05 to 200μM, and a low limit of detection 0.023μM were obtained by using DPV method. Usability of this biosensor was also confirmed by determination of CPA in tablet and spiked urine samples. Overoxidized polypyrrole-reduced graphene oxide offered a suitable substrate for immobilization of ds-DNA by which a new biosensor for determination of CPA was fabricated. Proposed biosensor can successfully be used for determination of CPA in urine samples taking advantage of electroanalytical methods. Graphical abstract.