A High-Linearity Glucose Sensor Based on Silver-Doped Con A Hydrogel and Laser Direct Writing

Abstract

A continuous glucose monitoring (CGM) system is an ideal monitoring system for the blood glucose control of diabetic patients. The development of flexible glucose sensors with good glucose-responsive ability and high linearity within a large detection range is still challenging in the field of continuous glucose detection. A silver-doped Concanavalin A (Con A)-based hydrogel sensor is proposed to address the above issues. The proposed flexible enzyme-free glucose sensor was prepared by combining Con-A-based glucose-responsive hydrogels with green-synthetic silver particles on laser direct-writing graphene electrodes. The experimental results showed that in a glucose concentration range of 0–30 mM, the proposed sensor is capable of measuring the glucose level in a repeatable and reversible manner, showing a sensitivity of 150.12 Ω/mM with high linearity of R2 = 0.97. Due to its high performance and simple manufacturing process, the proposed glucose sensor is excellent among existing enzyme-free glucose sensors. It has good potential in the development of CGM devices.

Challenges and Advances of Hydrogel-Based Wearable Electrochemical Biosensors for Real-Time Monitoring of Biofluids: From Lab to Market. A Review

“…106−109 Herein, sensitive components can be encapsulated in the hydrogel matrix to reduce sensor drift and degradation. 107 Recently, a conductive composite-hydrogel core−shell microneedle patch has been introduced to extract ISFs in a short time and to detect physiological signals in real time. 109 Ciui et al have developed a wearable bandage containing microneedle sensors that are designed to detect the enzyme tyrosinase (TYR) on the skin surface and beneath it.…”

“…For instance, sensitivity and precision are formidable challenges because of the dynamic nature of ISF composition . Hydrogels have been shown to improve biosensor sensitivity by providing a stable and biocompatible matrix for biomolecule immobilization that affects the detection accuracy and reliability. − Herein, sensitive components can be encapsulated in the hydrogel matrix to reduce sensor drift and degradation . Recently, a conductive composite-hydrogel core–shell microneedle patch has been introduced to extract ISFs in a short time and to detect physiological signals in real time .…”

A Polarity-Sensitive Far-Red Fluorescent Probe for Glucose Sensing through Skin

“…ConA is of value to continuous glucose biosensing because it can reversibly bind to mannose and glucose molecules without altering the protein’s covalent structures [ 21 ]. In addition, ConA has a high specificity to glucose and a ConA-based assay has demonstrated good specificity to glucose in the presence of galactose, fructose, lactose, and sorbitol [ 22 , 23 , 24 , 25 ]. Toxicology studies of ConA have previously been analyzed for the application of a minimally invasive glucose biosensor where the protein would be housed in a semipermeable membrane and showed an extremely low risk within the concentrations of interest [ 26 ].…”