title: Hollow PDA-Au nanoparticles-enabled signal amplification for sensitive nonenzymatic colorimetric immunodetection of carbohydrate antigen 125.
abstract: A novel colorimetric immunoassay was designed for the sensitive detection of carbohydrate antigen 125 (CA125). The success of this immunoassay relies on the use of hollow polydopamine-gold nanoparticles (PDA-Au) for signal amplification to achieve sensitive nonenzymatic colorimetric detection. In particular, PDA-Au was used as a stable and sensitive label and aminated-Fe3O4 magnetic nanoparticles (Fe3O4 NPs) were employed to immobilize capture antibody (Ab1) and acted as a separable immunosensing probe. PDA-Au exhibited high catalytic performance towards p-nitrophenol reduction and thus resulted in significant color change and UV/vis signal variations. The immunoassay was performed based on sandwich protocol. As compared to pure Au nanoparticles, the signal amplification and sensitivity of PDA-Au-based assay was significantly improved. For instance, the dynamic range of the developed colorimetric immunoassay for CA125 was 0.1-100 U/mL with a detection limit of 0.1 U/mL at S/N=3. In addition, this immunoassay was also tested for the analysis of clinical serum samples, which demonstrated its potential for practical diagnostic applications.
authors.affiliation: The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Leadernano Tech. L.L.C., Jining, Shandong 272000, PR China.
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Zhao
authors.affiliation: The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China.
authors.forename: Jinmao
authors.initials: J
authors.lastname: You
authors.affiliation: The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China. Electronic address: fengliquhn@hotmail.com.
authors.forename: Fengli
authors.initials: F
authors.lastname: Qu
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D018394:CA-125 Antigen / Q000097:blood*; D003124:Colorimetry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007211:Indoles / Q000737:chemistry*; D057230:Limit of Detection; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011108:Polymers / Q000737:chemistry*
chemical_list: D055910:Antibodies, Immobilized; D018394:CA-125 Antigen; D007211:Indoles; D058185:Magnetite Nanoparticles; D011108:Polymers; C568283:polydopamine; D006046:Gold
keywords: Carbohydrate antigen 125; Catalytic reduction; Colorimetric immunoassay; Magnetite; PDA-Au nanoparticles