Design and Fabrication of Enzymatic Potentiometric Biosensor Based on Flexible Printed Circuit Board for Glucose Detection.

This study investigated the development and optimization of a flexible printed circuit board-based glucose biosensor with an emphasis on high sensitivity, selectivity, and overall performance. Advances in glucose biosensing have highlighted its importance in medical diagnostics, especially diabetes management. The fabrication process involves depositing a RuO2 sensing film on a flexible printed circuit board (FPCB) by radio frequency sputtering. Enzyme-based modification using glucose oxidase (GOx), (3-aminopropyl) triethoxysilane (APTES), and glutaraldehyde (GA) to enhance selectivity and catalytic reactions. And through Scanning Electron Microscopy and electrochemical impedance spectroscopy, the sensing film, and the effect of modification on the charge transfer rate and performance improvement were analyzed. This glucose biosensor has excellent linearity, sensitivity, and reproducibility. The study also assessed response time and selectivity. The response time efficiency of the biosensor solidified its utility in point-of-care monitoring, while selectivity experiments validated its ability to distinguish glucose from interfering substances, ensuring accuracy in practical applications. According to the experimental results, the enzymatic glucose biosensor has the best average sensitivity and linearity of 44.42 mV/mM and 0.999 with a response time of 6 seconds.

The Characteristics Analysis of a Microfluid-Based EGFET Biosensor with On-Chip Sensing Film for Lactic Acid Detection.

In this research, a microfluid-based extended gate field-effect transistor (EGFET) biosensor with an on-chip sensing window (OCSW) was fabricated. The detection window was composed of six metal layers, and a ruthenium dioxide (RuO2) film was spattered on the surface and functionalized with lactase to detect lactic acid (LA). To detect LA in a more diversified way, a microfluidic system was integrated with the biosensor. Moreover, a special package was used to seal the sensing window and microfluidic tube and insulate it from other parts to prevent water molecule invasion and chip damage. The sensitivity analysis of the EGFET biosensor was studied by a semiconductor parameter analyzer (SPA). The static and dynamic measurements of the EGFET with sensing windows on a chip were analyzed. The sensing characteristics of the EGFET biosensor were verified by the experimental results. The proposed biosensor is suitable for wearable applications due to the advantages of its low weight, low voltage, and simple manufacturing process.