The effect of laser surface texturing on ZnO/MWCNT nanocomposite modified screen-printed carbon electrode for non-enzymatic glucose biosensor

A novel platform was proposed for the development of glucose biosensors, focusing on an innovative fabrication process based on simple surface modification techniques and non-enzymatic catalytic materials. The platform aimed to enhance biomolecule detection by utilizing a disposable and portable electrode design. Specifically, a screen-printed carbon electrode (SPCE) was selected as the base, and its carbon substrate was engraved using a pulsed fiber laser. Consequently, multi-walled carbon nanotubes (MWCNT) and zinc oxide (ZnO) nanoparticles were deposited on the surface of the laser-engraved screen-printed carbon electrode (LSPCE) using drop-casting and radio frequency (RF) sputtering techniques, respectively. The surface morphology and electrochemical performance of the modified electrodes was thoroughly characterized using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX) electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The ZnO/MWCNT nanocomposite was successfully applied to the LSPCE electrode surface, creating a porous spongy structure with mesopores in the 2-50 nm range. The ZnO/MWCNT/LSPCE exhibited high electrocatalytic activity for glucose oxidation when tested in phosphate-buffered saline (PBS) solution with a pH of 7.4. The developed glucose biosensor demonstrated a linear detection range from 1 to 10 mM of glucose with a sensitivity of 0.068 mu A mM- 1 and a detection limit of 0.43 mM. These findings indicate that the ZnO/MWCNT/LSPCE biosensor exhibits high performance in glucose detection, making it a promising candidate for practical applications in glucose monitoring.