Ultrathin ion-selective membranes for trace detection of lead, copper and silver ions

Voltammetric ion-selective electrodes (ISEs) based on poly(3-octylthiophene) (POT) in connection with ultra-thin membranes formulated different selective receptors (i.e., ionophores) are proposed for detection of lead, copper and silver ions (Pb2+, Cu2+ Ag+). The working mechanism the POT-membrane electrode is interconnected charge transfer processes both sides membrane, overall process depending electron POT lattice ultimately linked to ion at membrane–sample interface. This latter demonstrated be controlled by (i) membrane composition (ii) accumulation/stripping electrochemical protocol, allowing traces Ag+, Pb2+ Cu2+. In case Pb2+-selective electrode, voltammogram displays several peaks that hypothesized correspond ion–ionophore stoichiometries. Following signal related principal stoichiometry (1:1), a concentration as low 0.1 nM measurable. contrast, Cu2+- Ag+-selective show only one peak corresponding analyte, which can also detected nanomolar concentrations. results obtained three support their further usage multi-ion water samples through either multi-ionophore-based or multiple-electrode device. any case, composition, terms ionophore/exchanger molar ratio, key achieving successful analytical application. Upcoming efforts may directed replacement traditional trace metal hanging mercury drop develop more sustainable approach without diminishing performance.