Md Eshrat E Alahi
Macquarie University, Sydney, Australia
Title: Development of the selectivity of nitrate sensors based on ion imprinted polymerization technique
Biography
Biography: Md Eshrat E Alahi
Abstract
Nitrate-nitrogen is a naturally occurring ionic compound that is part of nature’s nitrogen cycle. Nitrate-N are readily lost to ground and surface water as a result of intensive agriculture, disposal of human and animal sewage and industrial wastes and the impact of elevated nitrate concentrations on water quality, has been identified as a critical issue facing New Zealand’s future. It is therefore, highly desirable to monitor water quality to facilitate regional councils and central governments to understand trends in concentrations and to develop a healthy water management policy. This research proposed the real-time detection of nitrate-N by employing electrochemical impedance spectroscopy (EIS) technique incorporating an interdigital capacitive sensor. Bulk polymerization is used to develop ion imprinted polymer to detect the nitrate ions in aqueous medium. Isobutyl nitrate was used as a template molecule with 1-allyl-2-thioure, ethylene glycol dimethacrylate and 2, 2′-azobisisobutyronitrile dissolved in acetonitrile for synthesis of imprinted polymer (IIP) for nitrate-N adsorption. Non imprinted polymer was also developed with the similar synthesis method. The developed IIP coating was used on the sensing surface. Sample nitrate-N measurement was done by using an imprinted and non-imprinted coating to see the difference of selective coating. Among the resistive and reactive part of the impedance, the earlier was used to develop a standard curve. The detection range is 0.1-10 mg/L (ppm). Unknown sample was measured with the presence of interfering ions (chlorine, bromine, sulphate and phosphate). The promising results highlight the extraordinary potential to develop low-cost, in-situ sensing system to detect nitrate contamination in surface or ground water.