Despite decades of work, current continuous glucose monitoring systems (CGMs) are still suffering signal drift, whether enzymatic or non-enzymatic, electrochemical or optical. Consequently, many CGMs still require frequent calibration from finger sticks, which in turn contributes the high cost and complexity of CMG products and the reluctance of rapid widespread adoption. In this work, we show a new strategy with the capability of self-calibration and self-correction to solve the instability by developing a dual-mode glucose sensing system.
Together with a newly developed diboronic acid molecule (DBA2+) we developed to sense glucose, a fluorescent molecule alizarin red S (ARS), was used for both optically and electrochemically probe glucose concentration. ARS is able to reversibly bind with boronic acids and has different electrochemical and optical signatures in different bound states. These signals changes of ARS upon binding with DBA2+ can be recovered by glucose, offering fluorescence and electrochemical signals. These dual-mode signals in one system can be used for self-calibration with algorithms.
The fluorescence of ARS exhibits more than 10 times enhancement in the presence of DBA2+ and decreases with the increase of glucose concentration (A and C), and ARS redox peak is also recovered by glucose (B and D). More importantly, the two signals show different response curves, which offers the basis for self-calibration.
Dual-mode (fluorescent and electrochemical) glucose sensing in one system was designed and demonstrated. The algorithms for self-calibration and self-correction is underway and will afford a solution for long-term stable continuous glucose monitoring.