Electrochemical on-chip deposition of proteins for further biodetection of several analytes by multiplexed chronoamperometry in a continuous flow µ-chamber is presented. Recently, an original deposition procedure was developed obtaining oriented and reversible immobilisation of an engineered photosystem II with an histidine-tag and its on-chip purification from bacterial crude extracts. The electrochemically assisted method started with the deposition of cysteamin on gold or platinum surfaces and further chemical synthesis of a spacer with a Ni-NTA end capable to link the engineered proteins. This technique is applied on a µ-chip assembled in a µ-chamber with an histidine-tagged alkaline phosphatase. Electrochemical deposition allowed this protein to be addressed only on a specific electrode in the µ-array in few minutes and under flow condition (flow-rate=10 µl/min).
1 Jan 2005
Sensors And Microsystems