Microgels-based In Vivo Biosensor for Continuous Blood Glucose Monitoring

Microgel-based in vivo biosensor is an innovative technological concept that focuses on creating nano- and/or micro-scale sensors for health monitoring. Microgel-based sensor (MBS) enables highly sensitive detection of a phenomenon-of-interest through electromagnetic characteristics. This paper presents a novel MBS for implantable health monitoring, and the research contributions can be summarized into two main aspects. Firstly, a novel synthesis method for microgel nanoparticles designed for blood glucose detection is proposed, and a new MBS sensitive to the in vivo microenvironment conditions is successfully synthesized. Comprehensive material characterization is conducted, including analyzing the material’s performance in different blood glucose environments and its temporal variations. Secondly, for this material, its dielectric constant is detected to respond to physiological signals in the human body. MBS is employed as in vivo sensors, converting biological signals within the body into morphological changes of microgel particles (i.e., switching between expansion and contraction forms). Through dielectric constant probes, we detect the dielectric properties of MBS for sensing applications, providing crucial insights for potential biomedical uses of microgels. To discuss the response of the proposed MBS to changes in blood glucose, we consider scenarios of high and low blood sugar. At 2 GHz, it is observed that the dielectric constant is 60.27 during low blood sugar and 20.13 during high blood sugar. These results indicate a high sensitivity of MBS to changes in blood glucose levels.