title: A highly sensitive immunosensor for calmodulin assay based on enhanced biocatalyzed precipitation adopting a dual-layered enzyme strategy.
abstract: Calmodulin (CaM) is a ubiquitous protein in eukaryotic cells, and it plays an important role in cancer progression. In this paper, a highly sensitive immunosensor adopting a dual-layered enzyme strategy was proposed for electrochemical detection of CaM. This immunosensor was constructed by introducing honeycomb-like mesoporous carbon (HMPC) as a sensor platform to sequentially immobilize antibody (Ab1), CaM and a multi-functionalized label. The label (HRP-PAupc-Ab1) was synthesized by covalently binding Ab1 and horseradish peroxidase (HRP) to poly(acrylic acid)-functionalized Au popcorn (PAupc) nanoparticles. A novel dual-layered enzyme strategy was employed by incubating HRP-secondary antibody (HRP-Ab2) onto the label surface and the enhanced biocatalyzed precipitation was therefore induced. This immunosensor exhibited satisfactory analytical performances for CaM detection with a linear response ranging from 5.0 pg mL(-1) to 100 ng mL(-1) and a detection limit of 1.5 pg mL(-1). The immunosensor has also been successfully applied to the CaM analysis in two cancer cells (HepG2 and MCF-7) with high sensitivity, which has shown great potency for cancer study.
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Ying
authors: Y
authors: Fu
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Kai
authors: K
authors: Liu
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Qianqian
authors: Q
authors: Sun
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Bin
authors: B
authors: Lin
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Danqin
authors: D
authors: Lu
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China. Electronic address: zaxu@chem.ecnu.edu.cn.
authors: Zhiai
authors: Z
authors: Xu
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Chen
authors: C
authors: Hu
authors: Institute of Biomedical Sciences, College of Life Science, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Guangjian
authors: G
authors: Fan
authors: Institute of Biomedical Sciences, College of Life Science, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Shengping
authors: S
authors: Zhang
authors: Institute of Biomedical Sciences, College of Life Science, East China Normal University, Shanghai 200062, People׳s Republic of China.
authors: Chuangui
authors: C
authors: Wang
authors: Department of Chemistry, East China Normal University, Shanghai 200062, People׳s Republic of China. Electronic address: wzhang@chem.ecnu.edu.cn.
authors: Wen
authors: W
authors: Zhang
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D014408:Biomarkers, Tumor; D015374:Biosensing Techniques / Q000379:methods*; D002147:Calmodulin / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D016062:Porosity
chemical_list: D055910:Antibodies, Immobilized; D014408:Biomarkers, Tumor; D002147:Calmodulin; D002244:Carbon; D006046:Gold; D006735:Horseradish Peroxidase
keywords: Biocatalyzed precipitation; Calmodulin; Cancer; Immunosensor