Laser-Assisted Sythesis and Texturing of Graphene Electrodes for Biosensing Devices

The pressing global demand for rapid, point-of-care detection of enveloped RNA viruses necessitates innovative sensor manufacturing approaches. We present a biosensor manufacturing method, focusing on flexible electronics employing graphene inks printed on flexible polymeric substrates. These are subsequently cured and laser-textured under conditions specific to our experiments, incorporating optimized electrode geometries. A crucial component of our advancement is the novel 2D layered structure and electrode coating geometry. In conjunction, the precise laser texturing and curing protocols allow for functionalization using single-stranded (ss) DNA primers. These primers, interacting with graphene layers, play a significant role in constructing DNA sensors adept at detecting enveloped RNA viruses directly, without the need for PCR amplification.<br/>Laser texturing significantly influences the hydrophobicity of these graphene sensors, enhancing their hydrophilic nature. Notably, differences were observed in hydrophilicity between different generations of sensors. Further, the methodology for DNA primer application is considered. While dip coating results in false negatives due to inadequate DNA ligand loading, drop casting amplifies the electrode resistance, denoting a superior yield in functionalization. Our evaluations further emphasize the superiority of unidirectional printing for sensor construction, evidenced by consistent, minimal resistance measurements.<br/>The DNA sensor construction strategies reported in our research offer compelling insights into the manufacturing and deployment of highly specific, portable devices for enveloped RNA virus detection at point-of-care facilities, all within minutes. These findings underscore the role of laser-assisted processes, optimal electrode design, and DNA functionalization methods in advancing the field of RNA pathogen detection.