A permittivity-based MEMS affinity glucose sensor with integrated temperature measurements

We present a proof-of-concept MEMS affinity sensor that measures the changes in dielectric properties of poly(acrylamide-ran-3-acrylamidophenylboronic acid) (PAA-ran-PAAPBA) polymer due to its specific, reversible binding with glucose. This sensor comprises capacitive electrodes sandwiching a solution of PAA-ran-PAAPBA polymer. Binding with glucose induces changes in the permittivity of the polymer, which can be measured as changes in capacitance to allow determination of the glucose concentration. A thin-film temperature sensor is also integrated within the device to maintain the polymer solution at a constant temperature via closed-loop control. Testing of the device with varying glucose-sensitive polymer compositions has shown that the device is capable of detecting glucose at physiologically relevant concentrations with excellent sensitivity and specificity. These results indicate that this MEMS-based sensor can be practically used for long-term, stable continuous glucose monitoring.