Ultrasensitive ELISA Using Enzyme-Loaded Nanospherical Brushes as Labels

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• 作者：Zhenyuan Qu ; Hong Xu ; Ping Xu ; Kaimin Chen ; Rong Mu ; Jianping Fu ; Hongchen Gu
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：October 7, 2014
• 年：2014
• 卷：86
• 期：19
• 页码：9367-9371
• 全文大小：369K
• ISSN：1520-6882

文摘

Improving the detection sensitivity of enzyme-linked immunosorbent assay (ELISA) is of utmost importance for meeting the demand of early disease diagnosis. Herein we report an ultrasensitive ELISA system using horseradish peroxidase (HRP)-loaded nanospherical poly(acrylic acid) brushes (SPAABs) as labels. HRP was covalently immobilized in SPAABs with high capacity and activity via an efficient 鈥渃hemical conjugation after electrostatic entrapment鈥?(CCEE) process, thus endowing SPAABs with high amplification capability as labels. The periphery of SPAAB-HRP was further utilized to bind a layer of antibody with high density for efficient capture of analytes owing to the three-dimensional architecture of SPAABs. Using human chorionic gonadotrophin (hCG) as a model analyte, the SPAAB-amplified system drastically boosted the detection limit of ELISA to 0.012 mIU mL^鈥?, a 267-fold improvement as compared to conventional ELISA systems.