Pyrene Derivative Incorporated Ni MOF as an Enzyme Mimic for Noninvasive Salivary Glucose Detection Toward Diagnosis of Diabetes Mellitus

Abstract

Herein, we demonstrate the detection of glucose in a noninvasive and nonenzymatic manner by utilizing an extended gate field-effect transistor (EGFET) based on the organic molecule pyrene phosphonic acid (PyP 4 OH 8 ) incorporated nickel metal− organic framework (Ni OM-MOF ). The prepared electrode responds selectively to glucose instead of sucrose, fructose, maltose, ascorbic acid, and uric acid in a 1× phosphate buffer saline solution. Also, utilizing the scanning Kelvin probe system, the sensing electrode's work function (Φ) is measured to validate the glucose-sensing mechanism. The sensitivity, detection range, response time, limit of detection, and limit of quantification of the electrode are determined to be 24.5 μA mM −1 cm −2 , 20 μM to 10 mM, less than 5 s, 2.73 μM, and 8.27 μM, respectively. Most interestingly, the developed electrode follows the Michaelis−Menten kinetics, and the calculated rate constant (k m ) 0.07 mM indicates a higher affinity of Ni OM-MOF toward glucose. The real-time analysis has revealed that the prepared electrode is sensitive to detect glucose in real human saliva, and it can be an alternative device for the noninvasive detection of glucose. Overall, the outcomes of the EGFET studies demonstrate that the prepared electrodes are well-suited for expeditious detection of glucose levels in saliva.

Copper Recovery from Mobile Phone Printed Circuit Board E-Waste and Transforming into CuO@C for Electrode Material in Extended Gate Field-Effect Transistors Facilitating Non-Enzymatic Ascorbic Acid Detection

“…Conversely, Cu/CuO@C/CP (Figure c) exhibited a good response to ascorbic acid concentrations ranging from 20 to 1900 μM, by a decent change in I d (response time of less than 10.6 s). Noteworthy, the CuO@C/CP (Figure d) demonstrated a favorable and pronounced response to ascorbic acid within the concentration range of 20–2300 μM, with a significant change in I d as well as a fast response time of less than 6 s. CM-CuO@C/CP obtained from the commercial source (Figure e) exhibited an uneven response to 20 μM and a favorable response to AA concentrations ranging from 60 to 2100 μM, by a decent change in I d with a response time of less than 13 s. The formula in the following eq was used to determine the limit of detection of the fabricated electrodes normalLOD = 3.3 × S b / S where S b = standard deviation of the blank signal and S = the slope of the calibration curve.…”