Metallo-Graphene Nanocomposite Electrocatalytic Platform for the Determination of Toxic Metal Ions

Sensors

Chandre M. Willemse²  Khotso Tlhomelang²  Nazeem Jahed¹  Priscilla G. Baker² 

[1] Sensor Lab, Department of Chemistry, University of the Western Cape, Bellville 7535, South Africa;

关键词: Nafion-Graphene nanocomposite;    mercury film;    trace metals;    square-wave anodic stripping voltammetry;   

DOI  :  10.3390/s110403970

来源: mdpi

【 摘 要 】

A Nafion-Graphene (Nafion-G) nanocomposite solution in combination with an in situ plated mercury film electrode was used as a highly sensitive electrochemical platform for the determination of Zn²⁺, Cd²⁺, Pb²⁺ and Cu²⁺ in 0.1 M acetate buffer (pH 4.6) by square-wave anodic stripping voltammetry (SWASV). Various operational parameters such as deposition potential, deposition time and electrode rotation speed were optimized. The Nafion-G nanocomposite sensing platform exhibited improved sensitivity for metal ion detection, in addition to well defined, reproducible and sharp stripping signals. The linear calibration curves ranged from 1 μg L⁻¹ to 7 μg L⁻¹ for individual analysis. The detection limits (3σ blank/slope) obtained were 0.07 μg L⁻¹ for Pb²⁺, Zn²⁺ and Cu²⁺ and 0.08 μg L⁻¹ for Cd²⁺ at a deposition time of 120 s. For practical applications recovery studies was done by spiking test samples with known concentrations and comparing the results with inductively coupled plasma mass spectrometry (ICP-MS) analyses. This was followed by real sample analysis.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.