N. Ruecha, N. Rodthongkum, D.M. Cate, O. Chailapakul, C.S. Henry
Chulalongkorn Uiversity, TH
electrochemical sensors, heavy metals detection, paper-based device
Electrochemical sensors based on filter paper and transparency film substrates have been prepared using screen-printing method for the detection of the heavy metals Pb2+, Cd2+, and Zn2+. The electrochemical characteristics of these electrodes were analyzed using cyclic voltammetry (CV) and anodic stripping voltammetry (ASV) while the surface roughness were measured using an optical profilometer. For electrochemical characterization by CV, electrodes on paper give a higher current response for ferri/ferrocyanide than transparency-based electrodes. When using ASV for the detection of heavy metals, the transparency-based device gave higher current response than paper-based device. Moreover, for the surface characterization using profilometry, carbon ink penetrated into the porous of filter paper but coated on the transparency film substrate affecting to surface roughness in transparency-based electrodes is higher than electrodes on paper. To improve the sensitivity of these devices, a graphene (G) and polyaniline (PANI) nanocomposite was prepared by polymerization of PANI in the presence of G and used for electrode modification. G/PANI nanocomposite-modified electrode was characterized by CV and used for heavy metals detection by ASV. This system will be very useful for portable environmental monitoring.