Dynamics of complex formation between biological and luminescent conjugated polyelectrolytes—a surface plasmon resonance study

• Published in: Biosensors & bioelectronics Vol. 20; no. 9; pp. 1764 - 1771
• Main Authors: Björk, Per, Persson, Nils-Krister, Peter, K., Nilsson, R., Åsberg, Peter, Inganäs, Olle
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-03-2005; Elsevier Science
• Subjects: Biocompatible Materials - chemistry; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Biotechnology; Conjugated polymer; DNA; DNA - analysis; Electrolytes - chemistry; Ellipsometry; Fundamental and applied biological sciences. Psychology; Immunoassay - instrumentation; Immunoassay - methods; Luminescent Measurements - instrumentation; Luminescent Measurements - methods; Materials Testing; Methods. Procedures. Technologies; Polymers - chemistry; Protein; Sensor; SPR; Surface Plasmon Resonance - instrumentation; Surface Plasmon Resonance - methods; Surface Properties; TECHNOLOGY; TEKNIKVETENSKAP; Thiophenes - chemistry; Various methods and equipments; Conjugated polymer; SPR; DNA; Protein; Sensor; Ellipsometry; Luminescence; Surface plasmon; Polyelectrolyte; Detector; Biosensor; Molecular complex; Resonance; Application
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2004.07.001

A water-soluble polythiophene, POWT, with zwitterionic peptide like side chains possess good characteristics for biosensor applications. The zwitterionic side chains of the polymer can couple to biomolecules via electrostatic and hydrogen bonding. This creates possibilities to imprint biomolecules to spin-coated polymer films with maintained functionality, and use the resulting matrix as a biosensor. Polymer-biomolecular interaction studies done with surface plasmon resonance (SPR) reveal a well performing sensor matrix with high affinity for DNA hybridizations as well as for protein detection. The responses are distinct and very specific. A directional dependence of antibodies binding to POWT layer has also been observed. The polymer films have also been characterized by optical methods. Emission and absorption measurements in different buffer systems confirm that the polymer matrix can undergo structural and conformational changes on surfaces. The dielectric function in the interval 300–800
nm of POWT is reported, based on variable angle spectroscopic ellipsometry. This modeling reveals that a considerable amount of water is included in the material. The polymer layer possesses the characteristics needed for biochip applications and micro array techniques.