Voltammetric determination of mercury in biological samples using crown ether/multiwalled carbon nanotube-based sensor

• Preparation, characterization and electro-catalytic activity investigation of Crown/MWCNTs/CPE
• Assay optimization, validation and real sample application
• Mercury determination with high sensitivity, selectivity and reproducibility

An electrochemical assay for sensitive and selective determination of mercury was suggested. Preparation, characterization, and testing of the electro-catalytic activity of Crown-ether/multi-walled carbon nanotubes (MWCNTs)/CPEs were performed. The voltammetric responses of modified electrodes with various sensing elements and nanomaterials were carefully investigated. Consequently, improving the sensitivity and selectivity were achieved using a combination of 12-crown-4-ether and MWCNTs (10% w/w for each). A linear response was observed from 5 to 110 μg/ml, with the detection limit (S/N = 3) of 0.25 μg/ml. The method was interference free from many species and successfully applied for the determination of mercury in blood, urine or tab-water samples with a high accuracy and precision comparable with the reference method (Atomic Absorption Spectroscopy AAS).