Arak University Colloid & Nanoscience Journal 2980-9215 3 4 2025 12 01 Development a copper complex/ reduced graphene oxide electrode for sensitive determination of glucose in real samples 775 790 735268 10.66224/CNJ.3.4.775 EN Masoud Rezaeinasab Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan 0000-0002-6589-8080 Masoud Rohani Moghadam Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan Samira Saeednia Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan Hasan Karami Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan Journal Article 2026 02 01 Prevention of diabetic complications and metabolic disorders, underscoring its clinical importance. In this study, a carbon paste electrode (CPE) was fabricated and functionalized with reduced graphene oxide (rGO) and Cu-L complex (Cu-L/rGO/CPE ) for electrochemical glucose sensing. Characterization via Fourier-transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and Raman spectroscopy confirmed the successful synthesis and integration of the rGO and Cu-L complex. Electrochemical analysis through voltammetry revealed that the modified electrode exhibited enhanced current responses toward glucose oxidation compared to the unmodified electrodes. The oxidation peak current increased proportionally with scan rate, allowing the calculation of the electron transfer coefficient (α) as 0.53. The apparent heterogeneous electron transfer rate constant (ks) was determined to be 4.27 × 10–4 s–1. Optimal catalytic activity was observed at physiological pH (~7). Modifier and nanosheets loadings were optimized at 5% and 2.5%, respectively, to maximize oxidation current. Quantitative analysis via linear sweep voltammetry (LSV) yielded a linear detection range from 5 to 90 µM, with a limit of detection (LOD) of 1.6 µM and limit of quantification (LOQ) of 4.9 µM. Chronoamperometric studies determined the glucose diffusion coefficient as 1.88 × 10–4 cm2/s. This electrode demonstrated excellent reproducibility and operational stability and validation of analytical performance in serum samples demonstrated recovery percentage of over 97%. Collectively, these findings affirm the efficacy of the Cu-L/rGO modified CPE as a sensitive and reliable electrochemical sensor for blood glucose monitoring. https://cnj.araku.ac.ir/article_735268_ed81d1d3aacca1c763e84d92b6bb86b5.pdf