Carbon nanofiber-assisted molecularly imprinted electrochemical sensors for selective hypoxanthine detection from real samples

In this study, thymine functionalized carbon nanofibers (Thy@CNFs) modified molecularly imprinted electrochemical sensors has been developed by copolymerization of pyrrole-co-pyrrole-3-carboxylic acid (Py-co-PyCOOH) over the Thy@CNFs. First, Thy@CNFs was deposited on a GCE, then Py-co-PyCOOH copolymer was synthesized in the presence of hypoxanthine (HYP) by electropolymerization on a GCE modified with Thy@CNFs. Characterization studies on variations at each stage of the MIP synthesis process were investigated via electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), attenuated total reflection-Fourier transform infrared spectrophotometry (ATR-FTIR), scanning electron microscopy (SEM), and contact angle measurements. Under optimal conditions, the Thy@CNFs modified MIP-based electrochemical sensor (Thy@CNFs/MIP/GCE) demonstrated a linear response from 1 x 10 ^–9 to 1 x 10 ^–8 M, having the limit of detection (LOD) of 1.71 x 10 ^− 10 M. Finally, it was found that MIP-based electrochemical sensor (MECs) was successfully utilized in detecting HYP in commercial serum samples and artificial urine with satisfactory recovery rates of 99.55% and 100.17%, respectively.