Zinc oxide nanopillars as an electrocatalyst for direct redox sensing of cadmium

In this paper, we report an ultrasensitive and selective technique for direct electrochemical sensing of cadmium (Cd) by zinc oxide nanopillars (ZONPs) synthesized using a facile chemical method. The synthesized ZONPs have been characterized in terms of their topological, morphological, elemental, structural, and optical properties using various microscopic and spectroscopic techniques. A gold electrode was modified with the as-synthesized ZnO nanostructures and utilized for direct redox sensing of Cd using cyclic voltammetry (CV) and chronoamperometric techniques. This fabricated sensor demonstrated excellent sensitivity and selectivity for direct redox sensing of Cd in real and laboratory samples. Using chronoamperometry, the developed sensor demonstrated ultra-sensitivity (10 mu A cm(-2) ppb(-1)) with a detection limit of 4 ppb (p-value < 0.0001, R-value > 0.99) in a linear range of 5-50 ppb. The enhanced reproducibility of the sensor in the presence of common interfering ions offers the potential for use in diagnostic applications involving food adulteration and in clinical healthcare. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.