In-situ synthesis of metal-3D graphene composites on flexible substrates as an advanced material for electrochemical biosensors and antibacterial performance

This work demonstrates a scalable, single-step approach by in-situ synthesis of tunable porous metal three-dimensional graphene (3DG), addressing key challenges in fabrication and functionality. Gold and silver nanoparticles anchored in porous 3D graphene (Au-3DG and Ag-3DG) composites were fabricated on in-house developed flexible metal-polyimide (Metal-P) films using laser (450 nm, 2.8 W) irradiation. The porous metal-3DG ensures a homogeneous metal distribution while overcoming multi-step processing, scalability issues, hazardous chemicals, and high-temperature requirements. With controlled metal salt incorporation, conductivity was enhanced from 1628 S/m to 2296 S/m, while elemental analysis confirmed 5.64 % gold and 11.95 % silver. The further study on electrochemical properties of Au-3DG and Ag-3DG was studied and compared using ascorbic acid (Vitamin C) and achieved a Limit of Detection (LoD) within the physiological range (0.6–2 mg/dL). Additionally, antibacterial property testing was done against Escherichia coli (E. coli) and was found to have an inhibition zone of 11 mm.