Ce-doped ZnO decorated cotton-derived carbon portable electrochemical sensor: Mechanistic unraveling and portable ultrasensitive detection of the organic pollutant chlorpromazine

Cotton-derived carbon coupled with Ce-doped ZnO via in-situ pyrolysis. • Portable Ce-ZnO-CNF@CC/SPE sensor was developed for on-site CPZ detection. • DFT verified optimized electronic structure and accelerated charge transfer. • Ultrasensitive response with a low limit of detection. • Reliable recovery in real samples for environmental monitoring. On-site monitoring of the emerging organic pollutant chlorpromazine (CPZ) is severely limited by the absence of low-cost, portable, and high-performance sensors. Herein, a disposable screen-printed sensor (Ce-ZnO-CNF@CC/SPE) was fabricated by in-situ growing Ce-doped ZIF-8 on cotton-derived carbon, followed by a one-step pyrolysis strategy. Density functional theory (DFT) calculations confirmed that trace Ce doping induces robust p-d-f orbital hybridization with the host lattice without structural disruption. The introduction of Ce 4f impurity levels narrows the band gap and significantly elevates the density of states near the Fermi energy. This robust electronic modulation accelerates charge-transfer kinetics and optimizes the CPZ adsorption affinity. Under optimized conditions, the fabricated sensor exhibited a remarkably broad linear range and an ultra-low limit of detection, along with excellent anti-interference, reproducibility, and stability. Furthermore, highly accurate and reliable recoveries were achieved in complex real-world matrices, including human serum and environmental water samples. This work provides a reliable portable platform for on-site CPZ monitoring and establishes an electronic structure-activity paradigm for designing highly dispersed, biomass-derived carbon-based sensors. Download: Download high-res image (151KB) Download: Download full-size image