Patent ID: 8743369

Claim:
A surface plasmon resonance (SPR) system using a ligand, the system comprising: a) a thin conducting layer suitable for SPR formed on a transparent substrate, the conducting layer comprising a plurality of electrodes; b) at least one flow channel crossing the electrodes at crossover regions; c) a power supply connected to the electrodes, and differently electrifying the electrodes at two different cross-over regions, such that the ligand flowing through the flow channel is attracted to and immobilized on the electrode at one of the cross-over regions, and repelled by and substantially prevented from immobilizing on the electrode at the other of the cross-over regions; and d) a photosensitive surface that generates SPR signals in response to light reflected from the crossover region at which the ligand is immobilized, that can be used to determine an SPR parameter, and generates reference SPR signals in response to light reflected from the crossover region at which the ligand is prevented from immobilizing, that can be used to normalize and correct the SPR signals from the crossover region at which the ligand is immobilized.