Fully integrated uric acid (UA) and glucose biosensors were fabricated on polydimethylsiloxane/polyimide platform by facile one step laser scribed technique. The laser scribed graphene (LSG) on the thin polyimide film was functionalized using pyrenebutanoic acid, succinimide ester (PBSE) to improve the electrochemical activity of the biosensors. The LSG was further decorated with platinum nanoparticles (PtNPs) to promote the electrocatalytic activity towards the oxidation of UA. Glucose oxidase was immobilized on the PtNPs modified surface for selective detection of glucose. The fabricated biosensors were characterized via scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), and electrochemical methods (cyclic voltammetry and amperometry measurements). Outstanding electrocatalytic activities toward oxidation of UA and glucose were demonstrated. A wide detection range of 5 µM to 480 µM UA with a high sensitivity of 156.56 µA/mMcm2 and a calculated detection limit (LOD) of 0.018 μM (S/N = 3) were achieved for the UA biosensor. The glucose biosensor exhibited a detection range of 5 µM to 3200 µM with a sensitivity of 12.64 µA/mMcm2 and an LOD of 2.57 µM (S/N = 3). These integrated biosensors offer great promise for potential applications in wearable UA and glucose sensing due to their good sensitivity, selectivity, and stability properties.
Keywords: Flexible biosensors; Glucose; Laser scribed graphene; Platinum nanoparticles; Uric acid.
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