Development of nano-bismuth sensor technology for detecting heavy metals

In this research, nano-bismuth(Bi) sensor electrode with high sensitivity and reliability has been developed for the trace analyses of heavy metals (Zn, Cd, Pb, Tl) in aqueous system. The Bi nanopowders with various particle size distributions were prepared by gas condensation method and the prepared nanopowders were strongly fixed on the screen-printed carbon or silver paste electrode. The sensitivity and detection limit of sensor electrodes were quantitatively estimated from the linear relationship between the heavy metal concentration and the peak current of square-wave anodic stripping voltammogram. From the comparison of sensor characteristics of nano-Bi electrode with ICP method and Hg/Bi film electrodes, it is suggested that the nano-Bi electrode can detect the traces of heavy metals smaller than 1ppb which can not be detected by ICP. In particular, the nano-Bi electrode exhibited a superior sensor characteristics such as detection limit, precision and accuracy of measurements, compared to the Hg/Bi film electrodes. Furthermore, the hardware and software for the portable sensor system (voltammetry) were manufactured, which makes the commercialization of the developed sensor technology earlier