Electrochemical Glucose Sensing Using Molecularly Imprinted Polyaniline–Copper Oxide Coated Electrode

Abstract

Diabetes is a chronic condition in which the body cannot produce or effectively utilize the produced insulin. Insulin is a hormone that regulates the blood glucose level (BGL). The long-term increased BGL can have serious health effects. Time-based monitoring of BGL is necessary for diabetic patients to avoid severe health conditions. For this purpose, a non-enzymatic electrochemical sensor for the non-invasive detection of glucose was prepared and tested in the framework of this research. The sensor was developed by combining the features of a molecularly imprinted polymer (MIP) and the highly conductive nature of polyaniline (PANI) and copper oxide nanoparticles (CuONPs). The CuONPs were electrodeposited onto the bare graphite electrode in the presence of 1.8 M H₂SO₄ solution. Using aniline as the monomer in presence of 0.5 M H₂SO₄, the copper oxide-coated pencil graphite electrode was electropolymerized to obtain a non-imprinted polyaniline/copper oxide-coated graphite electrode. Glucose was added to the electrolytic solution for the preparation of a molecularly imprinted polymer electrode. Cyclic voltammetry and amperometry were used to characterize the electrochemical response of the modified electrode in the presence and in the absence of glucose, as well as the selectivity of the sensor towards glucose detection in the presence of the interfering species. The morphological characterization of the fabricated electrode was investigated using scanning electron microscopy, Fourier transform-infrared spectroscopy, 3D surface profilometry, X-ray diffraction spectroscopy, and goniometry. From the electrochemical and morphological characterization results, it was inferred that the modified graphite electrode possesses imprinted sites, which helps to increase selectivity towards glucose sensing.