Facile fabrication of a flexible laser induced gold nanoparticle/chitosan/ porous graphene electrode for uric acid detection

We developed a simple, inexpensive, environmentally friendly one-step fabrication of a flexible laser induced graphene-chitosan-gold nanoparticles (LIG-CS-AuNPs) electrode. The fabrication was based on a laser treatment of polyimide (PI) film coated with CS solution containing gold ions (Au (III)). The AuNPs decorating the induced 3D graphene composite were uniformly distributed. The electrode exhibited good electrical conductivity and excellent electrocatalytic activity toward the oxidation of UA. To enable on-site monitoring of uric acid (UA) in blood serum by differential pulse adsorptive stripping voltammetry (DPAdSV), the electrode was coupled to a portable potentiostat connected to a cellphone to control and monitor analysis. The affecting parameters of DPAdSV were optimized. Under the optimal conditions for UA determination, the limit of detection of the developed sensor was 0.33 μmol L-1 and the limit of quantification 1.10 μmol L-1. Two linear ranges were produced: 1.0-30 μmol L-1 and 30-100 μmol L-1. The sensor was highly sensitive and demonstrated excellent reproducibility and selectivity, determining UA in blood serum with recoveries between 86.6 ± 0.6 and 94.7 ± 0.4%. The analysis results were in agreement with those of the hospital standard enzymatic method.