title: Organic silicone sol-gel polymer as a noncovalent carrier of receptor proteins for label-free optical biosensor application.
abstract: Optical biosensing techniques have become of key importance for label-free monitoring of biomolecular interactions in the current proteomics era. Together with an increasing emphasis on high-throughput applications in functional proteomics and drug discovery, there has been demand for facile and generally applicable methods for the immobilization of a wide range of receptor proteins. Here, we developed a polymer platform for microring resonator biosensors, which allows the immobilization of receptor proteins on the surface of waveguide directly without any additional modification. A sol-gel process based on a mixture of three precursors was employed to prepare a liquid hybrid polysiloxane, which was photopatternable for the photocuring process and UV imprint. Waveguide films were prepared on silicon substrates by spin coating and characterized by atomic force microscopy for roughness, and protein adsorption. The results showed that the surface of the polymer film was smooth (rms = 0.658 nm), and exhibited a moderate hydrophobicity with the water contact angle of 97°. Such a hydrophobic extent could provide a necessary binding strength for stable immobilization of proteins on the material surface in various sensing conditions. Biological activity of the immobilized Staphylococcal protein A and its corresponding biosensing performance were demonstrated by its specific recognition of human Immunoglobulin G. This study showed the potential of preparing dense, homogeneous, specific, and stable biosensing surfaces by immobilizing receptor proteins on polymer-based optical devices through the direct physical adsorption method. We expect that such polymer waveguide could be of special interest in developing low-cost and robust optical biosensing platform for multidimensional arrays.
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, No. 2 Linggong Road, Dalian 116023, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ren
authors.forename: Linghua
authors.initials: L
authors.lastname: Wang
authors.forename: Xiuyou
authors.initials: X
authors.lastname: Han
authors.forename: Jianfang
authors.initials: J
authors.lastname: Cheng
authors.forename: Huanlin
authors.initials: H
authors.lastname: Lv
authors.forename: Jinyan
authors.initials: J
authors.lastname: Wang
authors.forename: Xigao
authors.initials: X
authors.lastname: Jian
authors.forename: Mingshan
authors.initials: M
authors.lastname: Zhao
authors.forename: Lingyun
authors.initials: L
authors.lastname: Jia
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation*; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry*; D055096:Optical Devices; D011108:Polymers / Q000737:chemistry*; D011485:Protein Binding; D012825:Silicon / Q000737:chemistry*; D013205:Staphylococcal Protein A / Q000737:chemistry*
chemical_list: D055767:Immobilized Proteins; D007074:Immunoglobulin G; D011108:Polymers; D013205:Staphylococcal Protein A; D012825:Silicon