Due to their toxicity to humans and animals, heavy metals and nitrate in groundwater are of particular
concern. The combination of high toxicity and widespread occurrence has created a pressing need for
effective monitoring and measurement of nitrate and heavy metals in soil pore water and groundwater at
shallow depths. In this work, a new electrochemical sensing platform with the self-assembly nanobeadspacked
(nBP) hetero columns has been developed for the pH and nitrate measurements. In addition, for
on-site determination of cadmium (Cd(II)), a bismuth (Bi(III)) based polymer lab chip sensor using the
square-wave anodic stripping voltammetry (SWASV) sensing principle has been designed, fabricated and
successfully characterized. Factors affecting sensitivity and precision of the sensor, including deposition
potential and deposition time, were studied. Miniaturized electrochemical lab chip sensors could be very
valuable in environmental monitoring area due to their many benefits, such as greatly reduced sensing
cost, sensing system portability, and ease of use.