Orientation and capturing of antibody affinity ligands: Applications to surface plasmon resonance biochips

A surface plasmon resonance (SPR) sensor chip with immobilized protein G was used for simultaneously capturing, purifying and orienting antibody ligands. The ligands were further stabilized by chemical cross-linking. This procedure of designing the sensor chip improved efficient use of the ligands and could prolong the analytical use.The procedure was evaluated on standard dextran-coated sensor chips onto which commercial semi-purified antibodies towards human serum albumin and human troponin where captured and used for analysing their antigens.The procedure demonstrates a general design approach for presenting the biorecognition element on a biosensor surface which enhances sensitivity, stability and selectivity at the same time as an impure ligand is purified.

► Antibody ligands are oriented on surface plasmon resonance biochips by protein G.
► The biochips are used for assaying analytes to the oriented and bound antibodies.
► The chips are demonstrated on semi-purified antibodies towards albumin and troponin.
► The ligands can be chemically cross-linked prolonging their operational stability.