Laser-induced graphene ablated polymeric microfluidic device with interdigital electrodes for taste sensing application

• Microfluidic laser-induced graphene (LIG) based taste sensor is presented. • Interdigitated electrodes and microchannel were integrated on the same platform. • LIG-IDE device manifests lower detection limit than the human sensing threshold. • Selectivity of the device toward different analytes have been achieved. • The device provides a low-cost, point-of-care solution for diverse applications. On-site taste monitoring is important for human health, and widespread adoption requires low-cost, easy-to-fabricate technology and very precise portable equipment. The portability and high sensitivity of the device are regulated by the electrode configuration and, in turn, the fabrication techniques employed. In this context, herein, sensitive and specific electrical detection of five human gustative sensory tastes leveraging unique properties of graphene to realize optimized electrodes is presented. Herein, first, a Microfluidic device with integrated microchannel and Interdigitated electrodes (IDEs), based on a capacitive sensing mechanism, was prepared by the laser-induced graphene (LIG) technique. Electrochemical Impedance Spectroscopy (EIS) characterized the performance of the LIG-IDE microfluidic device. Under microfluidic conditions, the impedance change was linearly varying for the concentration of different chemicals in the range of 1–1000 ppm, and a minimum detection limit of 1 ppm was obtained. A comparison of the differences in capacitive response by LIG-IDE sensor for the five chemicals related to various tastes was also performed at different concentrations with respective real samples. This microfluidic taste sensor has the potential to provide low-cost, simple-to-integrate multi-functional point-of-care sensors for human sensory tastes, clinical, and environmental applications.