Sensitive electrochemical quantification of trace lead and cadmium of food samples based on B, N, S, and P-multiple-doped framework-based carbon aerogels.

[Display omitted] • A highly active metal-free nanosheet based on B, N, S, P-doped carbon was prepared. • The BNSP-C has a specific surface area of 755.58 m2/g and a conductivity of 75.82 Ω. • It has a linear range of 0.1–130 μg/L for Cd(II) and 2–150 μg/L for Pb(II). • LODs of the sensor are as low as 0.10 μg/L for Cd(II) and 0.45 μg/L for Pb(II). • It can be used for direct analysis of heavy metals in fruits, vegetables and rice. Designing and synthesizing efficient and economical electro-sensing interface materials is essential for screening trace heavy metal ions in foods. In this study, we developed a multi-doped BNSP-C material with Zeolitic imidazolate framework-8 (ZIF-8) and non-metallic atoms (B, N, S, and P) for the simultaneous detection of the heavy metals Cd(II) and Pb(II) in complex food samples. The in situ doping of heteroatoms positively modifies the microstructure and current efficiency of the carbon precursor, creating additional active sites and defects, and imparting the material with improved electrical properties. The detection system optimized by square-wave anodic stripping voltammetry, was sensitive up to 1.290 and 0.661 μA·μM−1·cm−2. BNSP-C-Nafion/GCE has a high selectivity for target ions under the challenge of multiple coexisting ions and molecules. Furthermore, the current signals of Cd(II) and Pb(II) only dropped to 97.19 % and 98.98 % of the initial currents after a 30-day stability test. The strong catalytic activity and persistence of the BNSP-C-Nafion sensor were confirmed. This study explored the enhancement and detection of the ZIF-based electrochemical signals. In addition, we provided a convenient and green electrochemical technique for the simultaneous detection of Cd(II) and Pb(II). [ABSTRACT FROM AUTHOR]