A non-enzymatic micro-needle patch sensor for free-cholesterol continuous monitoring
A patch type non-enzymatic free-cholesterol sensor was newly developed for continuous monitoring by using stainless steel based micro-needle patch and nanoporous platinum (NPt) sensing electrodes. The formed micro-needle patch was coated with parylene/gold/parylene film and selectively dry-etched to form the gold electrodes at the tips of micro-needles. The bare gold tips were finally electroplated with nanoporous platinum. The sensor was then characterized and analyzed by using cyclic voltammetry and chronoamperometry measurement techniques. The fabricated sensor exhibited high sensitivity of 305nA/mM·cm 2 and correlation coefficient of 0.964 in 0.1M PBS (pH 7.4). In the recovery test, recovery rate was more than 89%.