Highly Sensitive Novel Biosensor Based on an Immobilized lac Repressor This work was supported with grants given by the Swedish Engineering Research Council (TFR). Prof. Muller Hill and Dr. Andrew Barker are acknowledged for providing plasmids and the Escherichia coli BMH 8117 strain.

Sensitive repressors: The conformational change that occurs in the lac repressor protein when it binds to an inducer molecule has been used to develop a biosensor that permits the detection of the corresponding operator sequence or specific inducer molecules. A capacitive signal transducer was used to translate the conformational change of the lac repressor protein, covalently immobilized on a gold electrode (see schematic representation, A=bound inducer molecule or DNA), into a measurable signal.