SEAC Awards Section: Innovations in Electrochemical Sensing: Low-Cost, Portable Microfluidic Platforms

Electrochemical detection has emerged as a transformative approach in the development of low-cost, portable analytical devices, particularly through the integration with microfluidic platforms, which enable precise control of small sample volumes, enhance sensitivity through miniaturization, and allow for rapid, multiplexed analyses in a compact format. This talk will discuss advances from our laboratory in the design, development, and application of integrated electrochemical and microfluidic technologies for diagnostics. The first part of the presentation will focus on how our group has adapted screen-printed carbon electrodes (SPCEs) to microfluidic devices for a variety of sensing applications, ranging from the detection of heavy metals in environmental samples to infectious diseases in clinical samples. While SPCEs are easy to fabricate and low cost, they suffer from poor electron transfer rates, are difficult to miniaturize, and difficult to fabricate in simple, high-throughput methods. To this end, laser-induced graphene (LIG) electrodes offer an attractive alternative because they can be fabricated directly on surfaces using a common CO2 laser. The second part of this talk will focus on new methods of both modifying LIG electrodes for sensing applications and their incorporation into microfluidic and wearable devices. Using diazonium chemistry combined with Cu(I)-catalyzed azide-alkyne cycloaddition has allowed us to modify electrodes with stable mixed monolayers of PEG and ferrocene that both enable sensing applications while reducing non-specific adsorption. Electrochemical immunoassays will be shown to demonstrate the principle for label-free sensing. Finally, discussion of new methods that simplify incorporation of LIG electrodes into microfluidic devices will be presented. The method does not require transfer of the electrodes onto a new substrate and retains higher electrode surface area and electron transfer rates than previous methods of transfer.