One-step laser synthesis platinum nanostructured 3D porous graphene: A flexible dual-functional electrochemical biosensor for glucose and pH detection in human perspiration

There has been a recent increase in the demand for wearable sensors for sweat glucose monitoring to facilitate diabetes management in a patient-friendly and non-invasive manner. To address this issue, the key challenge lies in the design of flexible sensors with high conductivity, miniaturized patterning, and environmental friendliness. Herein, we introduce a flexible electrochemical sensing system for glucose and pH detection based on one-step laser-scribed PtNPs nanostructured 3D porous laser-scribed graphene (LSG). The as-prepared nanocomposites can synchronously possess hierarchical porous graphene architectures, whereas PtNPs can significantly enhance their sensitivity and electrocatalytic activity. Benefiting from these advantages, the fabricated Pt-HEC/LSG biosensor exhibited a high sensitivity of 69.64 mu A mM-1 cm-2 as well as a low limit of detection (LOD) of 0.23 mu M at a detection range of 5-3000 mu M (covering the glucose range in sweat). Moreover, the pH sensor was functionalized with polyaniline (PANI) on a Pt-HEC/LSG electrode, and it also exhibited high sensitivity (72.4 mV/pH) in the linear range of pH 4-8. The feasibility of the biosensor was confirmed by analyzing human perspiration during physical exercise. This dual-functional electrochemical biosensor displayed excellent per-formance, including a low detection limit, high selectivity, and great flexibility. These results confirm that the proposed dual-functional flexible electrode and fabrication process are highly promising for application in human sweat-based electrochemical glucose and pH sensors.