Affiliation:
1. Key Laboratory for Analytical Science of Food Safety and Biology (Ministry of Education & Fujian Province) College of Chemistry Fuzhou University Fuzhou 350116 P.R. China
Abstract
AbstractGiven the high solubility and mobility of hexavalent chromium in the environment and edible plants, the development of a suitable method for the screening and quantification of Cr(VI) is highly desirable. Herein, a selective and sensitive sensing method for detecting Cr(VI) in food grains was established, using an electrodeposited gold‐palladium bimetallic nanoparticles (BNPs) based electrochemical sensor and a microwave digestion procedure for chromium dissolution. The sensor interface was characterized by scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX) and cyclic voltammetry. The results indicate that the fabricated sensor has a larger active surface area and an enhanced electrocatalytic effect compared to the monometallic modification, leading to a significant increase in the electrochemical reduction current of Cr(VI) as a consequence of synergistic effects. Using square wave anodic stripping voltammetry, the sensor demonstrates a wide linear range (5–3000 μg L−1) and a low detection limit of 2.7 μg L−1 for Cr(VI), as well as considerable repeatability and stability. Satisfactory selectivity towards Cr(VI) was also demonstrated, even in the presence of 500‐fold Cr(III) and 100‐fold common heavy metal ions like Cd(II), Pb(II), and Hg(II). The proposed sensing method offers a promising alternative for rapidly identifying toxic Cr(VI) in water and food grains.