Stretchable and Flexible Non‐Enzymatic Glucose Sensor Based on Poly(ether sulfone)‐Derived Laser‐Induced Graphene for Wearable Skin Diagnostics

Abstract

The laser‐induced graphene (LIG) has a great potential in electrochemically active electrodes for wearable biosensors. Herein, for the first time, a stretchable and non‐enzymatic glucose sensor based on LIG derived from commercial poly(ether sulfone) (PES) membranes is reported. The LIG is in situ transferred onto an elastomer and tightly wrapped by the elastomer in one laser carbonization step. Superior to the conventional casting and demolding transfer process, this method avoids the LIG's morphology distortion and loss. By adjusting the laser settings and the patterns, hierarchically structured electrodes are prepared with greatly increased surface areas for glucose detection. The electrodeposited dendritic gold‐nanoparticles act as the catalyst for glucose sensing. The optimized flexible sensor demonstrates a linear range for glucose from 10 μm to 10.0 mm and a detection limit of 26 μm. The sensor shows a sensitivity of 0.024 ± 0.001 mA mm−1 and selectivity toward other interfering metabolites, as well as excellent performance under mechanical bending (stable performance after 500 bending cycles) and stretchability (resistance unchanged after 1000 cyclic stretching at 20% strain). Due to the simplicity of preparation and extraordinary fidelity, the novel PES‐LIG sensor is a promising candidate for the next generation of skin‐adherent diagnostic devices and wearable electronics.

Liquid Metal-Based Electronic Textiles Coated with Au Nanoparticles as Stretchable Electrode Materials for Healthcare Monitoring

“…The linearity of the current changes with the glucose concentrations between 0.0 and 1.0 mM demonstrated that the sensitivity of the AuLM textile (1 × 1 cm 2 ) was 97.254 ± 2.144 μA/mM (Figure b). This sensitivity value is comparable to that of gold-based high-performance glucose sensors reported in previous studies. − …”

“…First, a constant potential of 0.2 V was applied to the AuLM textile working electrode in 0.1 M NaOH electrolyte, followed by the successive injection of glucose solution into the electrolyte to adjust the glucose concentration from 0.0 to 1.0 mM with each injection (Figure a). The chronoamperometry test results indicated an LOD of 10 μM based on the common rule of SNR over 3 . The linearity of the current changes with the glucose concentrations between 0.0 and 1.0 mM demonstrated that the sensitivity of the AuLM textile (1 × 1 cm 2 ) was 97.254 ± 2.144 μA/mM (Figure b).…”

Pt/MXene-Based Flexible Wearable Non-Enzymatic Electrochemical Sensor for Continuous Glucose Detection in Sweat

“…Owing to the good correlation between glucose in blood and sweat, many non-invasive electrochemical wearable sensors of sweat glucose have been developed to replace invasive sensors of blood glucose. − However, most of these glucose sensors employ an enzymatic catalyst to detect glucose. − Although the enzymatic sensor is highly selective toward glucose molecules, its performance is easily degraded because of environmental changes, such as pH, temperature, and humidity variations. , Therefore, enzymatic glucose sensors are not suitable for wearable continuous glucose monitoring systems. Significant efforts have been devoted to developing non-enzymatic glucose sensors based on transition metals (Au, Pt, Cu, and Ni) and their transition metal oxides. − To obtain excellent performance, these sensors are generally operated under alkaline conditions (pH > 11) . However, the pH value of sweat in humans is close to neutral .…”

Doping of Laser‐Induced Graphene and Its Applications

“…reported a glucose sensor combining Au NPs with LIG, which was derived from commercial poly(ether sulfone) (PES) membranes. [ 162 ] The LIG‐Au glucose sensor demonstrated a sensitivity of 0.024 ± 0.001 mA mm −1 and a LOD of 26 µ m . The LIG‐Ni glucose sensor exhibited a wide linear range from 0.50 µ m to 1666 µ m , ultra‐high sensitivity of 2040 µA mM −1 ·cm 2 , and low LOD of 0.29 µ m .…”