A novel electrochemiluminescent immunosensor based on the quenching effect of aminated graphene on nitrogen-doped carbon quantum dots.
Nitrogen-doped carbon quantum dots (N-CQDs) with an average diameter of 2 nm were synthesized by carbonization of diethylene triamine pentacetate acid (DTPA). The simple prepared N-CQDs showed excellent electrochemiluminescence (ECL) property and were used as luminophors to fabricate a sandwich-type ECL immunosensor. Aminated graphene (NH2-G) was also synthesized and used as a label of secondary antibody. The labeled NH2-G could effectively quench the ECL of N-CQDs modified on electrodes due to ECL resonance energy transfer (ERET). Immunological recognition which induced ECL quenching enabled the quantitative determination of biomarkers. Alpha fetoprotein (AFP) was selected as a model analyte to investigate the analytical performance of the proposed immunosensor. Under optimal conditions, a good linear relationship between ECL intensity and the logarithm of AFP concentration was obtained in the range of 0.01-100 ng mL(-1) with the detection limit of 3.3 pg mL(-1). The proposed ECL immunosensor showed good stability, acceptable selectivity and reproducibility.
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Jing
J
Zhou
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Tongqian
T
Han
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Hongmin
H
Ma
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Tao
T
Yan
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Xuehui
X
Pang
School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
Yueyun
Y
Li
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: sdjndxwq@163.com.
Qin
Q
Wei
D000586:Amination; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay; D057230:Limit of Detection; D008163:Luminescent Measurements; D009584:Nitrogen / Q000737:chemistry*; D010316:Particle Size; D045663:Quantum Dots / Q000737:chemistry*; D000509:alpha-Fetoproteins / Q000032:analysis
D000509:alpha-Fetoproteins; D002244:Carbon; D006108:Graphite; D009584:Nitrogen
Alpha fetoprotein; Aminated graphene; Nitrogen-doped carbon quantum dots; Resonance energy transfer