Self-assembled polymeric nanoparticles film stabilizing gold nanoparticles as a versatile platform for ultrasensitive detection of carcino-embryonic antigen.
In this work, a novel impedimetric immunosensor was developed based on electrophoretic deposition of polymeric self-assembled nanoparticles for the sensitive determination of carcino-embryonic antigen (CEA). Biocompatible polymeric nanoparticles γ-PGA-DA@CS were prepared by self-assembly of chitosan (CS) and dopamine modified poly(γ-glutamic acid) (γ-PGA-DA) under mild conditions. A dense and nanostructured nanoparticles film was obtained on the electrode surface by electrophoretic deposition of γ-PGA-DA@CS nanoparticles. Gold nanoparticles (Au NPs) were then tightly anchored on γ-PGA-DA@CS film with homogeneous dispersion due to numerous exposed dopamine adhesive dots present on the surface of γ-PGA-DA@CS. The obtained Au/γ-PGA-DA@CS nanocomposite film not only increases the electrode surface area in nanoscale dimension, but also provides a highly stable and biocompatible matrix for the convenient conjugation of antibody, thus providing a high-efficiency immunoassay platform. Monoclonal antibodies to carcinoembryonic antigen (CEA-Ab) were effectively immobilized on the Au/γ-PGA-DA@CS film and a label-free impedimetric immunosensor was fabricated successfully as the ultimate goal. Under optimal conditions, the resultant immunosensor exhibited a wide linear range from 2.0×10-14gmL-1to 2.0×10-8gmL-1for the detection of CEA with a low detection limit of 10fgmL-1. To the best of our knowledge, this was the lowest detection limit compared with other counterparts of label-free impedimetric immunosensors. Moreover, the immunosensor showed high specificity, good stability and satisfactory reproducibility. As a proof of concept, the proposed strategy provided a promising and versatile platform for clinical immunoassay of other tumor markers and biomolecules.
Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P.R. China.
Sheng
S
Xu
College of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, P.R. China.
Rongli
R
Zhang
Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P.R. China.
Wei
W
Zhao
Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P.R. China.
Ye
Y
Zhu
Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P.R. China.
Wei
W
Wei
Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P.R. China. Electronic address: lxy@jiangnan.edu.cn.
Xiaoya
X
Liu
Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu Province, P.R. China. Electronic address: jingluo19801007@126.com.
Jing
J
Luo
D055910:Antibodies, Immobilized / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D002272:Carcinoembryonic Antigen / Q000097:blood*; D048271:Chitosan / Q000737:chemistry*; D058266:Dielectric Spectroscopy / Q000379:methods; D004298:Dopamine / Q000031:analogs & derivatives*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D015203:Reproducibility of Results
D055910:Antibodies, Immobilized; D002272:Carcinoembryonic Antigen; C511775:poly(gamma-glutamic acid); D011099:Polyglutamic Acid; D006046:Gold; D048271:Chitosan; D004298:Dopamine
Carcino-embryonic antigen; Chitosan; Dopamine modified poly(γ-glutamic acid); Electrophoretic deposition; Impedimetric immunosensor; Self-assembly