Commercially available continuous glucose monitors (CGMs) typically use electrochemical sensing methods and depend on the activity of enzymes, which is subject to drift with time. Newly developed optical CGMs also suffer from drift due to the photobleaching of the fluorescent dyes. Accordingly, existing CGMs must be calibrated over periods of hours to days. Here we developed a new molecule that can be used to sense glucose concentration through conductivity sensing. The new recognition molecule binds glucose with a suitable affinity (Kd = 1 mM) and selectivity, and hosts negative charges in physiological conditions after binding with glucose. The glucose binding and charge change alters the charge spices which contribute to the conductivity of solution. Glucose concentration therefore determines the conductivity of solution. We use a conductimetric method based on low voltage AC (∼20 mV) impedance spectroscopy which offers the promise of long-term stability. Current conductimetric sensors shall be interpreted with selective permeable membrane systems and would be used to monitor sampled fluid soon. This sensor does not need expensive enzyme and fluorescent dyes, and the preparation of the novel molecule is easy and low cost. The sensing strategy only uses low voltage power, and thus is more stable than enzymatic and optical methods, providing the possibility of less or no calibration. Our current conductimetric sensors are compatible with the well-developed high frequency AC microchip technology, which makes it lower-powered and easy to be miniaturized.
B. Wang: None. S. Pennathur: Board Member; Self; Laxmi Therapeutic Devices. Consultant; Self; Alveo Technologies. K. Chou: None.
American Diabetes Association (1-17-VSN-18 to S.P.)