A nanocomposite-decorated laser-induced graphene-based multi-functional hybrid sensor for simultaneous detection of water contaminants

Here, nanocomposite-decorated laser-induced graphene-based flexible hybrid sensor is newly developed for simultaneous detection of heavy metals, pesticides, and pH in freshwater. A series of deposition methods such as drop-casting, electroplating, and heating are adopted to modify and functionalize laser-induced graphene for engineering the high-performance detection at the individual sensor. A micro-dendritic structured bismuth@tin alloy inlaid on laser-induced graphene is prepared via a simple ex-situ electrodeposition method and thermal treatment for detecting heavy metals. The electrochemical performance is evaluated through the simultaneous determination of lead and cadmium ions at the optimized deposition potential of -1.2 V for 170 s, and a wide detection concentration range of 2-250 ppb and low detection limits (1.6 ppb and 0.9 ppb, respectively) are achieved. The pesticide sensor co-modified by zirconia nanoparticles and multilayered Ti3C2Tx-MXene is successfully implemented with a good linear performance for parathion after an optimal accumulation time of 120s. It realizes a low detection concentration range (0.1-5 ppb) with a detection limit of 0.06 ppb. Furthermore, a polyaniline/antimony/laser-induced graphene-based pH sensor is also integrated, showing an excellent sensitivity of -72.08 mV pH-1 in the pH range (2-9). They are also measured and characterized in different real water samples, exhibiting an acceptable detection performance, which provides promising applicability in the on-site monitoring of pollutants in the water environment.