A step towards non-invasive diagnosis of diabetes mellitus using in situ synthesized MOF–MXene hybrid material with extended gate field-effect transistor integration

Abstract

The increasing demand for non-invasive and non-enzymatic glucose sensors is driven by the objective of eliminating the need for blood pricks from the body and enabling enzyme-free detection of glucose for diagnosing diabetes mellitus. To address this need, we synthesized Ni MOF–MXene (Ni_BDC-MXene) hybrid material through a one-pot synthesis method, which acts as a catalyst to detect salivary glucose using an extended gate field effect transistor (EGFET) method. The resulting sensor exhibits good selectivity towards glucose over common interfering molecules such as sucrose, fructose, maltose, uric acid, and ascorbic acid under physiological conditions in saliva. The fabricated electrode demonstrated high sensitivity of 531.78 μA mM⁻¹ cm⁻² with a detection range of 10 μM to 1100 μM, a sensor response time of less than 5 s, and a limit of detection (LOD) of 0.29 μM. The real saliva sample measurements under postabsorptive and postprandial conditions highlight the electrode's effectiveness in detecting salivary glucose. In addition to EGFET measurements, scanning Kelvin probe (SKP) measurements were performed to understand the mechanism of charge transfer between the glucose and Ni_BDC-MXene/CP electrode. Overall, the EGFET results demonstrate the capability of the sensor to detect salivary glucose in hypoglycemia, normal, and hyperglycemia ranges.