Traditional laboratory-based sensing strategies for food contaminant detection are often limited because they are time-consuming and expensive and require trained personnel, which makes them unsuitable for routine sensing. Therefore, the scientific and industrial community is showing enormous interest in the design and development of portable sensing devices for the on-site and point-of-care detection of food contaminants. Portability is one of the chief characteristic features of designing contemporary analytical devices. Portable devices have received tremendous attention, as these novel devices have advanced the field of sensing. Various sensing strategies have been utilized for on-site detection of food contaminants. Among these, portable electrochemical devices have emerged vigorously in the past few years. Scientists and industrialists have worked effortlessly to develop portable electrochemical devices for a minute amount of food contaminant detection in water bodies and food products. The current work aims to demonstrate recent research progress related to the design, development, and improvement of portable electrochemical devices for detection of food contaminants.

Evolution of a simple, efficient and reproducible strategy for the rational design of hierarchically structured metal chalcogenide-based supercapacitors has attracted considerable research interest in recent years. Herein, a facile wet-chemistry approach is employed to design three-dimensional forest-like porous nickel sulfide nanotrees on nickel foam (NiS NTs/Ni foam) for use as a cathode material in hybrid supercapacitors. The growth time plays a crucial role in controlling the surface morphology, and the optimal growth conditions (3 h at 85 °C) led to the growth of forest-like NiS NTs/Ni foam with reliable adherence. The forest-like NiS NTs/Ni foam shows maximum areal and specific capacities of 752.71 μA h cm⁻² and 342.1 mA h g⁻¹ at a current density of 4 mA cm⁻², with an excellent cycling stability of 89.4%. This result is primarily due to the availability of more surface-active sites in the well-defined hierarchical architecture, which allow the rapid diffusion of electrolyte ions and minimize the electron transport limitation. Utilizing the hierarchical NiS NTs/Ni foam as a cathode and activated carbon-based anode, we further fabricated a hybrid supercapacitor, which demonstrates a wide potential window of 1.6 V with high areal energy and power densities of 0.472 mW h cm⁻² and 21.5 mW cm⁻², respectively. The fabricated hybrid supercapacitor is successfully utilized to drive various electronic gadgets for real-life applications. The electrochemical performance of a hierarchically structured NiS-based binder-free electrode with our facile approach paves a new pathway for the development of novel metal chalcogenides for high-performance hybrid supercapacitors.