Bulletin of Biotechnology, cilt.6, sa.2, ss.67-72, 2025 (Hakemli Dergi)
In this study, we developed a highly sensitive amperometric glucose biosensor based on a nanocomposite of electrochemically synthesized polypyrrole and metal oxide nanoparticles. A platinum electrode was coated by PPy film by cyclic voltammetry, which served as a host matrix for the immobilization of GOD using a chitosan-glutaraldehyde cross-linking system. We conducted a comparative study to evaluate the signal-enhancing effects of incorporating ZnO, TiO₂, and zinc titanate (ZnTiO₃) nanoparticles into the immobilization matrix. A comparative analysis of the current response to varying glucose concentrations was conducted for enzyme electrodes modified with metal oxide nanoparticles (NPs) at concentrations of 0.1, 0.5, and 2.0 mg/mL. The results unequivocally demonstrated that across all three concentrations tested, the electrode modified with ZnO NPs (PPy/ZnO/GOD) yielded a substantially superior amperometric response compared to those incorporating other metal oxides. This pronounced enhancement in current signal underscores the exceptional efficacy of ZnO nanoparticles in facilitating electron transfer within the biosensor matrix. Subsequent to this optimization, the ZnO NP-modified biosensor was deployed for the quantitative determination of glucose in a series of real-world samples, namely apple juice, grape juice, a fizzy beverage, and honey. To rigorously validate the accuracy and reliability of the developed biosensor, its performance was benchmarked against a commercially available spectrophotometric glucose assay kit. The analytical data obtained from both methods exhibited a strong correlation, confirming the high degree of accuracy of the fabricated biosensor. Consequently, it can be confidently asserted that the developed amperometric glucose biosensor exhibits significant potential and robustness for the precise and reliable determination of glucose concentrations in complex real-sample matrices.