Highly Sensitive and Flexible Copper Oxide/Graphene Non-Enzymatic Glucose Sensor by Laser Direct Writing

Accurate and convenient detection of human blood glucose levels is an effective method for early diagnosis of diabetes and prevention of complications. The flexible and wearable electrochemical glucose sensor with low cost, fast responsiveness, good stability, reliability, and high sensitivity has attracted much attention in monitoring glucose concentration. The preparation of a conductive layer with catalytic activity on a flexible substrate is the key to making a wearable glucose sensor. Here, graphene composite materials sintered with copper oxide (CuO) nanoparticles are successfully prepared on a polyimide film by laser direct writing method and fabricated a flexible non-enzymatic glucose sensor using laser-engraved graphene (LEG) as a conductive electrode. The CuO/LEG sensor exhibits a high sensitivity of 619.43 mu A mm-1 cm-2 in 0-3 mm glucose and 462.96 mu A mm-1 cm-2 in 0-8 mm glucose. In addition, the CuO/LEG sensor shows good reproducibility, high anti-interference capability, and long-term stability. It also presents good bending stability, which can maintain 82.40% initial current after 100 times bending. Moreover, the CuO/LEG sensor has an obvious step-ampere response in the detection of sweat samples, indicating the great potential of wearable sweat sensors. A high-performance copper oxide (CuO)/laser-engraved graphene (LEG) based non-enzymatic glucose sensor is prepared by laser direct writing method. The CuO/LEG sensor exhibits a high sensitivity of 619.43 mu A mm-1 cm-2 in 0-3 mm glucose and 462.96 mu A mm-1 cm-2 in 0-8 mm glucose. Moreover, the CuO/LEG sensor also shows good selectivity, reproducibility, long-term stability, and bending stability. image