title: Biofunctional polyelectrolytes assembling on biosensors - A versatile surface coating method for protein detections.
abstract: This paper reports a surface functionalization strategy for protein detections based on biotin-derivatized poly(l-lysine)-grafted oligo-ethylene glycol (PLL-g-OEGx-Biotin) copolymers. Such strategy can be used to attach the biomolecule receptors in a reproducible way simply by incubation of the transducer element in a solution containing such copolymers which largely facilitated the sensor functionalization at an industrial scale. As the synthesized copolymers are cationic in physiology pH, surface biotinylation can be easily achieved via electrostatic adsorption on negatively charged sensor surface. Biotinylated receptors can be subsequently attached through well-defined biotin-streptavidin interaction. In this work, the bioactive sensor surfaces were applied for mouse IgG and prostate specific antigen (PSA) detections using quartz crystal microbalance (QCM), optical sensor (BioLayer Interferometry) and conventional ELISA test (colorimetry). A limit of detection (LOD) of 0.5 nM was achieved for PSA detections both in HEPES buffer and serum dilutions in ELISA tests. The synthesized PLL-g-OEGx-Biotin copolymers with different OEG chain length were also compared for their biosensing performance. Moreover, the surface regeneration was achieved by pH stimulation to remove the copolymers and the bonded analytes, while maintaining the sensor reusability as well. Thus, the developed PLL-g-OEGx-Biotin surface assembling strategy is believed to be a versatile surface coating method for protein detections with multi-sensor compatibility.
authors.affiliation: State Key Laboratory of Precision Measuring Technology & Instruments, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Han
authors.affiliation: State Key Laboratory of Precision Measuring Technology & Instruments, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Precision Measuring Technology & Instruments, College of Precision Instrument and Opto-electronics Engineering, Tianjin University, Tianjin 300072, China. Electronic address: xduan@tju.edu.cn.
authors.forename: Xuexin
authors.initials: X
authors.lastname: Duan
mesh_terms: D000327:Adsorption; D000818:Animals; D015374:Biosensing Techniques; D001710:Biotin; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D008297:Male; D051379:Mice; D000071228:Polyelectrolytes; D017430:Prostate-Specific Antigen / Q000032:analysis*; D058525:Quartz Crystal Microbalance Techniques; D019809:Streptavidin; D013499:Surface Properties
chemical_list: D007074:Immunoglobulin G; D000071228:Polyelectrolytes; D001710:Biotin; D019809:Streptavidin; D017430:Prostate-Specific Antigen
keywords: Enzyme-linked immunosorbent assay; Immuno-sensor; Interferometry; Polyelectrolyte; Quartz crystal microbalance; Surface functionalization