Signal amplification in capillary electrophoresis based chemiluminescent immunoassays by using an antibody-gold nanoparticle-DNAzyme assembly.
A signal amplification strategy based on antibody-gold nanoparticle-DNAzyme assembly in capillary electrophoresis based chemiluminescent immunoassays (CE-CLIA) was developed. In this CE-CLIA, antibody-AuNP-G-quadruplex/hemin was incubated with limited amount of antigen, and the formed immunocomplex and unreacted antibody-AuNP-G-quadruplex/hemin were then separated by CE and detected by CL. Due to the strong CL catalytic ability of G-quadruplex/hemin DNAzyme and a high loading ratio of DNAzyme on each AuNP, the assay was very sensitive. By taking carbohydrate antigen 19-9 (CA19-9), one of the most important carbohydrate tumor marker as the model analyte, the proposed CE-CLIA method for CA19-9 detection showed a linear range from 0.025 to 1.00 U/mL with a detection limit of 0.016 U/mL (signal/noise=3), which was more sensitive than the methods previously reported for CA19-9 quantification. The method was applied to quantify CA19-9 in human serum samples, and analytical results were in a good agreement with those obtained by using an established ELISA method.
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, China.
Min
M
Shi
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, China. Electronic address: zhaoshulin001@163.com.
Shulin
S
Zhao
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, China.
Yong
Y
Huang
Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, China.
Limin
L
Zhao
Department of Chemistry and Biochemistry, Jackson State University, 1400 Lynch St., Jackson, MS 39217, USA.
Yi-Ming
YM
Liu
D000906:Antibodies / Q000737:chemistry*; D014408:Biomarkers, Tumor / Q000097:blood / Q000737:chemistry; D018395:CA-19-9 Antigen / Q000097:blood / Q000737:chemistry; D021881:DNA, Catalytic / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D054856:G-Quadruplexes; D006046:Gold / Q000737:chemistry*; D006427:Hemin / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results
D000906:Antibodies; D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D021881:DNA, Catalytic; D006427:Hemin; D006046:Gold
Capillary electrophoresis; Carbohydrate antigen 19-9; Chemiluminescent immunoassays; Gold nanoparticles; Signal amplification