Detection of the trace level of heavy metal ions by pH-regulated conical nanochannels

The exceeding of the heavy metal ions concentration in human body to a certain critical level can lead to serious diseases. Since this critical level is usually of trace value, developing an efficient yet economic method to estimate that value is both desirable and necessary. Based on the ion current rectification behavior of a conical, polyethylene terephthalate nanochannel surface modified by 18-crown-6, we propose a method to estimate the concentration of Pb2+ in an aqueous medium. Numerical simulation is conducted to examine the performance of this nanochannel under various conditions by varying the background LiCl concentration, the concentration of Pb2+, and the degree of surface modification. Regression analysis is also conducted to obtain the range of Pb2+ concentration suitable for detection and its lower limit. We show that the performance of the nanochannel proposed is satisfactory. The possibility of detecting the concentration of Cu2+ by the nanochannel proposed is also examined. ? 2020 Taiwan Institute of Chemical Engineers