Conversion of Electronic Waste to an Electrochemical Sensor for Dopamine: Using MXene-Modified Liquid Crystal Display Panels

In this study, we report a novel sensing platform based on used liquid crystal display (LCD) as a working electrode in electrochemical sensing applications. This paves the way for the sustainable recycling of e-waste and a cost-effective approach for the development of electrodes. Here, the discarded LCD was modified with Ti3C2Tx MXene and was used as a sensing platform for the detection of dopamine (DA). Cyclic voltammetry studies revealed that the Ti3C2Tx-modified LCD shows a better enhancement in the sensor response compared with the bare LCD. The developed sensor was able to detect DA from 10 nM to 100 μM with a limit of detection of about 4.5 nM. Additionally, the sensor also shows very high selectivity, stability, and repeatability towards the detection of DA. The practical applicability of the sensor is also evaluated by detecting DA form human serum samples. We have tested with different LCD panels from different manufacturers and found that all the used LCDs are able to detect DA with minor changes in the current response. To the best of our knowledge, the possibility of using scrap LCD screens for electrochemical sensing applications has not been reported to date. Using discarded e-waste materials as electrodes for electrochemical sensing applications will be both a sustainable and cost-effective approach. Additionally, the current innovation provides an economical solution for managing or reducing the increasing amount of e-waste generated in the environment. Hence, reusing the disposed LCDs as electrodes in electrochemical sensing applications will open up new avenues toward cost-effective and sustainable methods for upcycling hazardous e-waste.