Microneedles with phenylboronic acid-containing polymer and carbon nanotubes for interstitial fluid glucose measurements

A novel microneedle (MN) sensor coated with a glucose-sensitive composite material was developed to measure glucose levels in interstitial fluid (ISF). The composite combines a polymer containing glucose-responsive phenylboronic acid (PBA) moieties with conductive carbon nanotubes (CNTs). This design leverages the polymer's reversible swelling response to glucose, altering CNT distribution and, consequently, electrical percolation on the MN surface. We optimized PBA content and CNT loading for sensitivity by testing the MN in an ISF-mimicking gel. In animal models, the MN sensor's electrical current responses closely correlated with blood glucose levels, demonstrating clinical-grade accuracy comparable to conventional glucometers.