Multi-effect coupling enhanced PtPdRhFeCu HEA/N-Cu-ZnSe@C biosensing device for pesticide residue detection in fruits and vegetables with ultra-low detection limit.

The accurate monitoring of pesticide residues in agricultural products is critical for maintaining food quality and human health. The development of innovative analysis techniques capable of satisfying the stringent demands of practical applications is the key to building intelligent and highly-efficient pesticide detection equipment. Here, an ultrasensitive electrochemical biosensor has been reported, which utilizes quinary PtPdRhFeCu high-entropy alloy mesoporous nanotubes (PtPdRhFeCu HEA mNTs) and N/Cu dual-atom anchored ZnSe@C (N-Cu-ZnSe@C) as electrode materials. Multi-effect coupling (defect effect, high entropy effect, lattice distortion effect and doping effect), endows the proposed sensing interface with extremely high electronic conductive properties and unprecedentedly large electroactive surface area, which could heavily promote the charge transfer capability, meanwhile assists the acetylcholinesterase (AChE) with high affinity towards its substrate, thereby significantly improving the pesticide analysis performance of the sensor. Remarkably, the detection limit of this assembled biosensor for aldicarb sulfone and methamidophos detection are notably low at 2.32 fM and 4.58 fM, respectively. Moreover, this biosensor demonstrated wide detection ranges (7 pM ∼ 70 nM for methamidophos and 1 pM ∼ 0.1 μM for aldicarb sulfone), high sensitivity and specificity, along with good recovery rates (86.67 % ∼ 117.14 %) in real samples. This signal amplification strategy enhances the analysis capability by integrating multiple effects, and provides an innovative analysis tool for hazardous substance analysis in food safety and environmental monitoring research.