Detection of Glucose Using Recombinant Corn Mn Peroxidase with Square Wave and Linear Sweep Voltammetry on Disposable Screen-Printed Electrodes

We report the development of a novel, disposable electrochemical biosensor for the sensitive and selective detection of glucose, employing modified screen-printed electrodes and electrochemical techniques such as square wave voltammetry (SWV) and linear sweep voltammetry (LSV). The biosensor integrates a recombinant, plant-produced manganese peroxidase enzyme derived from corn, in combination with glucose oxidase, bovine serum albumin, gold nanoparticles, and gold-modified screen-printed electrodes to create a robust and cost-effective sensing platform. Glucose detection was performed across a concentration range of 0.007 to 6.5 mM using LSV, which yielded a regression line correlating current response with glucose concentration and a detection limit of 3.9 µM. SWV measurements were conducted over a broader range of 0.0006 to 6.5 mM, producing a calibration curve with excellent linearity (correlation coefficient R² = 0.9971) and a significantly lower detection limit of 0.29 µM. Sensor selectivity was evaluated using both LSV and SWV in the presence of common interferents such as caffeine, aspartame, and ascorbic acid, confirming high specificity. The biosensor exhibits a rapid response, user-friendly operation, and minimal contamination risk, making it highly suitable for point-of-care diagnostics and glucose monitoring in food samples. This study demonstrates the potential of integrating bioengineered enzymes with nanomaterial-enhanced electrodes to develop high-performance biosensing technologies with strong scalability, ease of fabrication, and real-world applicability.