Highly sensitive electrochemical analysis of diuron utilizing Super P carbon black-bridged halloysite nanotubes/whisker carbon nanotubes conductive networks

A novel one-pot ultrasonic-assisted method was developed to fabricate Super P carbon black (SPCB)-bridged conductive networks comprising halloysite nanotubes (Hal) and whisker carbon nanotubes (WCN). This WCN/SPCB/Hal nanocomposite was engineered into a sensing platform on glassy carbon electrode (GCE) for diuron (DU) detection. In this architecture, the non-entangled WCN backbone offered high electrolyte adsorption capacity, facilitating the rapid ion transport. Hal provided high-affinity sites to preconcentrate DU at the interface, while SPCB bridged the conductive pathways between WCN and Hal. The resulting WCN/SPCB/Hal/GCE sensor demonstrated good electrochemical performance for DU detection with detection limit of 29.45 nM and sensitivity of 1.6121 μA/μM (linear range: 0.1–20 μM). It also demonstrated good reproducibility, repeatability, and anti-interference capability. The practical application of WCN/SPCB/Hal/GCE in juice samples yielded favorable recoveries of 95.18–102.70% and low relative standard deviations ranging from 2.30% to 4.30%, confirming its potential for rapid DU analysis in fruit-based matrices.