Porous Microneedle-Based Potentiometric Sensor for Intradermal Electrolyte Monitoring

Abstract

A porous microneedle (PMN)-based potentiometric ion sensor for transdermal monitoring of electrolytes in the interstitial fluid was developed. The carbon coating with an ionselective membrane was formed on half of the needle tip as the working electrode, while the Ag/AgCl reference electrode was mounted on the PMN chip. This design of a single needletype configuration allows lower invasive transdermal sensing than the conventional system with multiple needle electrodes. The fabricated potentiometric sensor showed the near-Nernstian responses to Na + concentration in the excised pig skin, demonstrating the applicability for monitoring intradermal electrolytes.