Novel structured light-addressable potentiometric sensor array based on PVC membrane for determination of heavy metals

The paper discussed a novel structured light-addressable potentiometric sensor (LAPS) array based on PVC membrane for determination of heavy metal cations simultaneously. For LAPS array fabrication, part of the silicon substrate which was defined as non-sensitive area was heavily doped with boron and had thick oxide formation. Then PVC (polyvinyl chloride) membrane for respective cations (Pb2+, Cb2+, Zn2+) was prepared uniformly on corresponding sensitive area. Through new structure, the elaborated LAPS array had the advantages of excellent calibration stability (e.g. lower standard deviation from ±3.1 mV to ±0.5 mV for Pb-LAPS) and reasonable good selectivity. Sensors based on these membranes had showed a Nernstian response of slope (28.7–29.3 mV/dec) over the concentration ranges of 10−5 to 10−1 mol/L. At the meantime, the electrochemical behavior in terms of the detection limit, linear response range, response time, long-time stability and effect of silanization had also been investigated.