Biofunctional structural design of SAW sensor chip surfaces in a microfluidic sensor system

• Published in: Sensors and actuators. B, Chemical Vol. 124; no. 1; pp. 46 - 52
• Main Authors: Jung, Adrian, Gronewold, Thomas M.A., Tewes, Michael, Quandt, Eckhard, Berlin, Peter
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-06-2007
• Subjects: Aminocellulose monolayers; Assaying; Biofunctional modifications of SAW sensor chips; Chips; Enzymes; Glucose oxidase; Microfluidics; Monolayers; NH 2-(organo-) polysiloxane composites; RNA anti-thrombin aptamer; Sensors; Silicon dioxide; Surface acoustic waves; Glucose oxidase; NH 2-(organo-) polysiloxane composites; Biofunctional modifications of SAW sensor chips; Aminocellulose monolayers; RNA anti-thrombin aptamer
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2006.11.040

Surface acoustic wave (SAW) sensor chips with a gold or SiO
2-polymer surface were integrated into a microfluidic S-sens K5 sensor system to be modified by a novel procedure. Self-assembled composite monolayers were formed on the sensor chip surfaces, starting from special aminocellulose derivatives or from NH
2-(organo-) polysiloxanes. Subsequently, the interface layers were biofunctionalized. In one assay, the enzyme glucose oxidase was immobilized on the aminocellulose surface. In a second assay, the formed composite monolayers became thrombin-sensitive by immobilization of an RNA
anti-thrombin aptamer. The biofunctionalized surfaces did only display negligible amounts of non-specific protein binding with respect to elastase and bovine serum albumin (BSA). Thrombin was bound highly specific and with high sensitivity. It was possible to regenerate the surfaces under flow conditions.