Maintaining the concentrations of various ions in body fluids is critical to all living organisms. In this contribution, we designed a flexible microneedle patch coupled electrode array (MNP-EA) for the in situ multiplexed detection of ion species (Na+ , K+ , Ca2+, and H+ ) in tissue interstitial fluid (ISF). The microneedles (MNs) are mechanically robust for skin or cuticle penetration (0.21 N/needle) and highly swellable to quickly extract sufficient ISF onto the ion-selective electrochemical electrodes (∼6.87 μL/needle in 5 min). The potentiometric sensor can simultaneously detect these ion species with nearly Nernstian response in the ranges wider enough for diagnosis purposes (Na+ : 0.75−200 mM, K+ : 1−128 mM, Ca2+: 0.25−4.25 mM, pH: 5.5−8.5). The in vivo experiments on mice, humans, and plants demonstrate the feasibility of MNP-EA for timely and convenient diagnosis of ion imbalances with minimal invasiveness. This transdermal sensing platform shall be instrumental to home-based diagnosis and health monitoring of chronic diseases and is also promising for smart agriculture and the study of plant biology
Researcher/Author: Dan Dan Zhu, Yu Rong Tan, Le Wen Zheng, Jia Zheng Lao, Ji Yang Liu, Jing Yu and Peng Chen
Published in: ACS Appl. Mater. Interfaces2023
To download the paper, please proceed to: 10.1021/acsami.3c00573