Carbon nanofiber-enhanced molecular imprinted electrochemical sensor for hypoxanthine detection

A molecularly imprinted electrochemical sensor (MIP) was developed using thymine-functionalized carbon nanofibers (Thy@CNFs) to enable selective detection of hypoxanthine (HYP). The sensor was fabricated by first depositing Thy@CNFs onto a glassy carbon electrode (GCE), followed by electropolymerization of a pyrrole-co-pyrrole-3-carboxylic acid (Py-co-PyCOOH) copolymer in the presence of HYP. Each modification step was characterized using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and contact angle measurements. Under optimized conditions, the Thy@CNFs-modified MIP sensor (Thy@CNFs/MIP/GCE) exhibited a linear response to HYP concentrations ranging from 1 x 10-9 to 1 x 10-8 M, with a detection limit of 1.71 x 10-10 M. Finally, the sensor was successfully applied to commercial serum and artificial urine sample, achieving recoveries of 99.55% and 100.17%, respectively, demonstrating its accuracy, precision, and practical applicability in real sample analysis.