Synthesis and application of bismuth nanoparticle-loaded longan porous carbon for simultaneous electrochemical determination of Pb(II) and cd(II) in seafoods

The discarded longan shell-derived porous carbon material (LPC) served as a scaffold for synthesizing bismuth nanoparticle-loaded longan porous carbon nanocomposite (BiNPs@LPC) via a hydrothermal method . Then BiNPs@LPC was utilized to modify screen-printed carbon electrodes (SPCE) for simultaneous detection of Pb(II) and Cd(II) by square wave anodic stripping voltammetry (SWASV). The material was thoroughly characterized by scanning electron microscopy , X-ray diffraction, Raman spectra , Brunauer-Emmett-Teller analysis, electrochemical impedance spectroscopy and cyclic voltammetry . BiNPs@LPC exhibited abundant porous structures, high surface area , and numerous active sites, which could improve significantly response sensitivity. Under optimal conditions, the peak currents of Pb(II) and Cd(II) exhibited favorable linear relationships with the concentration within a range of 0.1–150 μg L −1 , with detection limits (S/N = 3) of 0.02 μg L −1 and 0.03 μg L −1 , respectively. BiNPs@LPC/SPCE demonstrated remarkable selectivity , stability and repeatability. The proposed method was successfully applied for the detection of Pb(II) and Cd(II) in seafoods achieving satisfying recovery of 97.8%–108.3% and 96.7%–106.4%. These excellent test properties were coupled with convenience for batch preparation of the modified electrodes , highlighting its potential for practical applications in heavy metal detection of real samples.