Synchronous detection of cadmium and lead in honey, cocos nucifera and egg white samples using multiwalled carbon nanotube/hyaluronic acid/amino acids nanocomposites

Abstract

Electrochemical Synchronous detection of cadmium (Cd(II)) and lead (Pb(II)) was obtained by acid treated multiwalled carbon nanotube (A-MWCNT) functionalized with hyaluronic acid (Hyalu) and this mixture was separately further modified with l-cysteine (l-Cys) and l-serine (l-Ser). Under the optimized circumstance best voltammetric responses were produced by A-MWCNT/Hyalu/l-Cys and A-MWCNT/Hyalu/l-Ser modified electrodes. The peak current was linearly dependent on the Cd(II) and Pb(II) concentrations in the range from 0.4 to 4 µg L−1. The sensitivities were calculated as 0.7 µA/nM (Cd(II)) and 3.5 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.6 µA/nM (Cd(II)) and 2.6 µA/nM (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. From the calibration plot LODs were calculated to be 0.032 µg L−1 (Cd(II)) and 0.015 µg L−1 (Pb(II)) for A-MWCNT/Hyalu/l-Cys/GCE and 0.057 µg L−1 (Cd(II)) and 0.034 µg L−1 (Pb(II)) for A-MWCNT/Hyalu/l-Ser/GCE. Moreover, the proposed electrodes were subjected to the real sample application in honey, cocos nucifera and egg white.