Electrical detection of self-assembled polyelectrolyte multilayers by a thin film resistor

The use of a silicon-on-insulator (SOI) based thin film resistor to monitor the buildup of polyelectrolyte multilayers was investigated. The sheet resistance of the field effect device was sensitive to variations of the potential ψs at the silicon oxide surface. It was found that the deposition of the differently charged polyelectrolytes results in defined potential shifts, which decrease with the number of layers deposited. The field effect based device based on SOI was well suited for the quantitative determination of charge variations at complex interfaces and was also useful for the quantitative analysis of differently functionalized field effect devices.