Biodegradable wearable sensors for rapid non-destructive analysis of pesticides on plants and foods

Abstract

Wearable sensors technology in plant monitoring is emerging, disruptive and innovative tools offering new opportunities to enhance agricultural productivity and environmental sustainability as highlighted by World Economic Forum in Top 10 Emerging Technologies of 2023. On-site and nondestructive decentralized analysis of pesticides is essential for the effective management of agrochemicals on crops and foodstuff in precision agriculture and food safety that is not achievable with gold standard methods. Here, we develop eco-friendly substrates/support of biodegradable cellulose acetate (CA) films plasticized with diverse amounts of glycerol (GLY) or triethyl citrate (TEC) fabricated by casting method as a sustainable choice for portable sensing devices applications. The wearable devices containing full electrochemical sensing system were produced by screen-printing technology on green plasticized CA substrates to rapidly (3.28 min) and simultaneously detect agrochemicals directly on the surface of agricultural and food products. The wearable dual-sensor integrates diquat sensing by square wave voltammetry (SWV) with carbendazim and diphenylamine detection via differential pulse voltammetry (DPV) on a single platform with single microliter sample droplet. Reliable agrochemical measurements are conducted with low-cost environmentally friendly sensory platform (<US$ 0.077 per unit) in fruits, vegetables, saliva and water samples coupled with a Sensit BT portable analyzer connected via Bluetooth to a smartphone, laptop or tablet. Our sustainable wearable dual-sensor exhibits an attractive analytical performance with robustness against severe bending strains, reproducibility and selectivity offering on-site rapid, continuous, cost-effective, simultaneous and reliable monitoring, addressing the existing gap in integrated approaches for multiplexed agrochemical detection in nondestructive decentralized analysis.