Biosensors and Bioelectronics: X (May 2022)
Flexible hydrogel non-enzymatic QCM sensor for continuous glucose monitoring
Abstract
Continuous physiological monitoring is a promising alternative to current diabetes mellitus and other chronic disease monitoring for obtaining big data sets to help individualized therapy. Whereas traditional enzymatic sensors degrade rapidly during use for several days even in mild conditions. Non-enzymatic sensors outperform enzymatic ones in terms of cost, sensitivity, and stability. Here, we present a continuous glucose monitoring platform consisting of a quartz crystal microbalance (QCM) quartz and a flexible hydrogel recognition system. A stretchable hydrogel is employed as the support material and antifouling membrane, and glucose-sensitive monomer phenylboronic acid (PBA) is employed as the recognition part. Specifically, the hydrogel membrane with PBA is firmly adhered on the electrode surface of the quartz crystal. The designed sensor exhibited recorded-low detection limit of glucose (0.15 mg L−1) among reported QCM sensors, which was about 20 times lower than previous reports. Its limit of quantitation achieved 0.5 mg L−1 with a linear range of 0.5–120 mg L−1. The response time of the PBA hydrogel based QCM sensor was 32 s, and it exhibited excellent stability over 40 days. The accurate glucose continuous measurements from the fish blood and other media show the practical utility, which paves the way for the non-enzymatic glucose QCM sensors in wearable electronics.