One-step laser-induced Cu-embedded graphene for non-enzymatic glucose sensing in beverages

Abstract

The detection of glucose in beverages is crucial for dietary management and healthcare. Excessive sugar consumption can lead to severe conditions, such as obesity, diabetes, cardiovascular diseases, and cancer. In this study, Cu-embedded laser-induced graphene (Cu/LIG) materials were fabricated for non-enzymatic glucose detection using a simple, direct, and cost-effective laser-patterning method on a Cu2+/ethyl-cellulose/polyimide membrane. The experimental results showed that the Cu/LIG electrode exhibited lower charge transfer resistance and a distinct diffusion process compared to the LIG electrode. This improvement can be attributed to the optimized graphene formation achieved by employing ethyl-cellulose (EC) and CuCl2 as combustion promoters. Under optimal conditions, Cu/LIG-600 demonstrated excellent electrocatalytic activity for glucose oxidation, with a low response concentration (5 μM), fast response time (2.0 s), and detection ranges of 0.005–0.525 mM (I-t) and 0.5–4.0 mM (CV). Moreover, the sensor exhibited high selectivity, stability (retaining over 90 % activity after 28 days), and satisfactory recovery rates for spiked glucose in Cola, Sprite, Black Tea, and sugarless Soda Water, indicating its potential for non-enzymatic glucose detection in beverages.