title: Detection of vascular endothelial growth factor based on rolling circle amplification as a means of signal enhancement in surface plasmon resonance.
abstract: Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis. It has been identified as an ideal biomarker for staging of many kinds of cancers, so more specific and intense signal is desirable for VEGF biosensors so that the sensors may have more valuable clinical application. Herein, we report a highly sensitive and selective surface plasmon resonance (SPR) sensor for VEGF detection by using two DNA aptamers which target different VEGF domains used as the capture and detection probe, respectively. Moreover, by making use of carboxyl-coated polystyrene microspheres, 3'-NH2 immobilized aptamer and 3'-NH2 modified primer DNA are loaded through amidation onto the sensing layer for further rolling circle amplification (RCA) process to amplify the SPR signal. With the well-designed sensing platform, VEGF can be determined in a linear range from 100 pg mL(-1) to 1 μg mL(-1) with a detection limit of 100 pg mL(-1). Due to its high specificity and desirable sensitivity, this RCA assisted SPR method may be a useful tool for the assay of VEGF in the future. What is more, by replacing the sensing element, i.e., the aptamer of VEGF used in this work, more biosensors for sensitive detection of other biomarkers proteins can be fabricated based on the strategy proposed in this study.
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Chen
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Yafei
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Fangjie
authors.initials: F
authors.lastname: Qi
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Jiangjiang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Applied Nanoscience, Pusan National University, Miryang 627-706, Republic of Korea.
authors.forename: Kwangnak
authors.initials: K
authors.lastname: Koh
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Laboratory of Biosensing Technology, School of Life Sciences, Shanghai University, Shanghai 200444, PR China; Department of Biochemistry and State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, PR China. Electronic address: genxili@nju.edu.cn.
authors.forename: Genxi
authors.initials: G
authors.lastname: Li
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D004867:Equipment Design; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization / Q000379:methods; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D042461:Vascular Endothelial Growth Factor A
keywords: Aptamer; Rolling circle amplification; Surface plasmon resonance; Vascular endothelial growth factor