Synthesis of polypyrrole (PPY) functionalized halloysite nanotubes (HNTs): An electrochemical sensor for ibuprofen

Over-the-counter availability of non-steroidal anti-inflammatory drugs (NSAIDs) without prescription, for medicinal use has led to abuse in accidental and intentional suicides. In this context, the present study accentuates on the development of simple and reliable electrochemical sensor based on the HNTs coated with in-situ polymerized polypyrrole (HNT/PPY) for detection of ibuprofen (IBP). Surface functionalization of HNTs with PPY increased the electron rich centres on the electrode surface with an evident ∼8 fold increase in electrochemical active surface area (EASA) as compared to bare electrode, facilitating electron transfer rate. The analytical and electrochemical characterization of the sensor was carried out with TEM, EDX-mapping, FTIR, XPS, XRD, CV and DPV. The proposed sensor exhibited a sensitive response towards oxidation of IBP with linear dynamic range (LDR) of 0.1-100 µM and offers a fairly good limit of detection (LOD) of 0.9 µM. The practical utility of the sensor was tested for real time detection of IBP from biological matrix (urine). Sensitive, selective and stable response of HNT/PPY towards electrochemical oxidation of IBP suggested it is a promising platform for IBP detection and can be used in forensic field and clinical set ups.