PEG-assisted NiO nanostructure films: Comparative analysis of electrochemical and microwave methods for non-enzymatic glucose sensing

This study explores the fabrication of NiO nanostructure films for non-enzymatic glucose sensing using electrochemical (EC) and microwave-assisted (MW) methods, with polyethylene glycol (PEG) as a key morphological modifier. PEG incorporation significantly enhances the uniformity and porosity of PEG assisted NiO (pNiO) films, improving glucose sensing performance in both fabrication techniques. Notably, EC-prepared electrodes (EC-pNiO) are fabricated under acidic conditions, while MW-prepared electrodes (MW-pNiO) require basic conditions. This distinction affects both film morphology and sensor performance, with EC-pNiO exhibiting superior sensitivity (983 μA/mM cm²) and a lower detection limit (6 × 10⁻³ µM) due to more controlled growth and film uniformity. However, MW-pNiO benefits from compatibility with basic conditions, aligning with the optimal operational pH for metal oxide-based sensors. Real-sample analysis further demonstrates the practicality of the optimized EC-pNiO electrode for glucose detection in human serum. This work underscores the critical influence of preparation conditions and PEG on electrode morphology and performance, establishing electrochemical methods as a versatile and efficient approach for tailored sensor fabrication.