Smartphone-based plant-wearable microfluidic sensor with self driven electrolyte for in-situ detection of methyl parathion

A smartphone-based plant-wearable microfluidic sensor based on capillary adsorption and driving electrolyte flow in micro-channels has been developed for in-situ detection of methyl parathion (MP). This sensor could achieve online collection, flow enrichment and reliable electrochemical detection of MP. Laser direct writing technology was adopted to construct laser induced graphene-gold nanoparticles (LIG-Au) electrodes and micro-channel molds in one step, where the molds were used to produce PDMS micro-channels. The microfluidic sensor, made of LIG-Au on polyimide film and PDMS channels, could be attached to plant surfaces, and the capillary action of the micro-channel drove electrolyte flow to accelerate the pre-enrichment process of MP detection, shortening detection time (saving about 381 s of pre-enrichment time). The proposed microfluidic sensor had excellent MP detection performance from 0.001 μM to 200 μM and low detection limit of 0.000646 μM. It was used to detect MP on epipremnum aureum and lettuce, in which the good spiking recoveries verified its reliable real samples determination. This novel microfluidic sensor provides new vision for low-cost, simple fabrication, in-situ collection, rapid real sample detection of MP, demonstrating enormous application prospects in the fields of monitioring food safety and safeguarding human health.