Metal ion sensing using ultrathin organic films prepared by the layer-by-layer adsorption technique.

Abstract

Bilayer films of poly(ethyleneimine) and poly(ethylene-co-maleic acid) have been prepared using the layer-by-layer assembly technique. These films have been characterized using surface plasmon resonance (SPR). Exposure to aqueous solutions of metal acetate (metal = copper, nickel) resulted in a shift in the position of the SPR curve. This shift could be monitored by observing the intensity of the reflected laser beam at fixed angle and concentrations of copper acetate down to at least 10-6 M could be detected.