Quartz Crystal Microbalance Sensor Deposited with Langmuir−Blodgett Films of Functionalized Polythiophenes and Application to Heavy Metal Ions Analysis

Abstract

Two novel functionalized polythiophenes, poly[3-(6-hydroxyhexyl)thiophene] and poly(3-octanethio-2,2‘-bithiophene), were used as selective coating materials for quartz crystal microbalance (QCM) sensors. These conductive polymers on admixture with stearyl alcohol were deposited on QCM devices by the Langmuir−Blodgett (LB) technique. These LB films exhibited a selective adsorption for the first-row transitions ions in the Irving-Williams order due to the complexation of metal ions with sulfur atoms in the polymers. These LB film coated QCM sensors were found applicable in detecting heavy metal ions in aqueous solution, which are major pollutants in wastewater. The coated QCM sensors can selectively adsorb heavy metal ions (Hg2+) from solution over a wide range from 0.1 to 100 ppm concentration by complexation with sulfur atoms in the polymers. The bound mercury could be removed by ethylenediaminetetraacetic acid (EDTA) solution. The presence of ferrous, lead, cobalt, and chromium cations in the solution did not interfere with the detection of mercury ions.

Adsorption kinetics of a fluorescent dye in a long chain fatty acid matrix

“…There are several examples of obtaining thin-film devices for optical recording and storage [1,2], nonlinear optics [3,4], sensors [5], etc. Among the various thin film preparation techniques [6] Langmuir-Blodgett (LB) technique is one of the most versatile and promising method to form organized molecular assemblies with a well-defined surface and layer structure [6,7].…”

Application of polyaniline for the reduction of toxic Cr(VI) in water

“…In this regard some studies have focused on electrochemical interaction of conducting polymers with toxic metals [12][13][14]. Results of these studies have lead to the application of conducting polymers in analysis [4,[14][15][16][17] and abatement [18][19][20] of some toxic metals from the environment. * Corresponding author.…”

Detection of lead(II) and silver(I) in aqueous solution using a piezoelectric device

“…17 The piezoelectric device offers an alternative to the measurement of reaction kinetics of heterogeneous systems involving biomacromolecular interactions using the BIAcore TM instrument, although in the latter case the kinetic analyses have been more extensively investigated and developed. [18][19][20] Second, we are interested in the development of piezoelectric devices for the detection and determination of metal ions in solution, 14,[21][22][23][24][25][26][27] where sorbents chemically attached to the crystal are employed in order to obtain the selectivity required to determine one metal ion in the presence of others.…”