Construction and Evaluation of an Enzyme-Free Glucose Sensor Based on CuO/Porous Nitrogen-Doped Graphene Nanocomposites: Integration of Nanomaterial-Oriented Research into an Undergraduate Laboratory Experiment

Abstract

Recognizing the gap between traditional verification-oriented undergraduate chemistry experiments and real-world nanomaterial research practice, we designed a comprehensive laboratory experiment integrating nanomaterial synthesis, characterization, and electrochemical sensing for third-year and senior undergraduate students majoring in analytical chemistry, environmental engineering, or materials science. This experiment focuses on addressing the limitations of enzyme-based glucose sensors (e.g., strict environmental dependence, poor stability) by constructing an enzyme-free glucose sensor using copper oxide/porous nitrogen-doped graphene (CuO/PNrGO) nanocomposites. Students sequentially synthesize porous nitrogen-doped graphene (PNrGO) via calcination, prepare CuO/PNrGO through a hydrothermal method, and fabricate the enzyme-free sensor. They characterize the nanomaterials using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption while evaluating the performance of the sensor via cyclic voltammetry (CV) and amperometric i–t curves. The optimized CuO/PNrGO sensor exhibits a high sensitivity of 2020.54 μA·mM–1·cm–2, a low detection limit of 0.13 μM, excellent anti-interference ability, and long-term stability. This experiment bridges foundational chemistry principles (electrochemistry and materials science) with interdisciplinary research, enhancing students’ experimental skills, data analysis capabilities, and scientific literacy.