Simplifying the Incorporation of Laser-Induced Graphene into Microfluidic Devices

Laser-induced graphene (LIG) electrodes have many attractive properties that make them promising platforms for many electrochemical applications. However, their fabrication is currently limited to a small number of substrates, with the most widely used being polyimide. Incorporating LIG electrodes into microfluidic devices is challenging because it requires transfer onto other substrates compatible with microfluidics. Transferring LIG electrodes to other substrates has been demonstrated, but it requires complicated mechanical procedures that impact electrode performance. Here, a simple transfer process has been developed that maintains the structural and electrochemical integrity of the LIG electrodes. The transferred LIG electrodes were characterized using morphological and electrochemical techniques, revealing comparable performance to nontransferred LIG in both surface-sensitive and surface-insensitive redox processes. The transferred electrodes were then incorporated into a microfluidic device, and their performance as a sensing platform was verified using the detection of dopamine in the presence of uric acid and ascorbic acid. This simple and versatile method of integrating LIG electrodes into microfluidic systems offers many opportunities for future applications.