Needle-shaped glucose sensor based on polypyrrole doped with glucose oxidase

We demonstrate a highly sensitive enzymatic glucose sensor fabricated by screen printing. To enhance the sensitivity of the sensor, the electrode base was first modified by gold nanoparticles (AuNPs) deposition. Glucose oxidase (GOx) immobilization on the electrode was achieved by pyrrole polymerization using chemical doping method. The fabricated sensor was characterized using optical microscope and scanning electron microscope (SEM) and electrochemical experiments. The glucose detection was performed in 0.1 M phosphate buffer saline (PBS, pH 7.4) solution at operating potential of + 0.4 V using amperometric i-t curve. The sensor exhibited a high and reproducible sensitivity of 14.453 nA/mM, response time similar to 25 s, linear range from 1 mM to 10 mM (R-2 = 0.9946) and long-term stability up to 30 days in vitro.