Electrochemiluminescence immunosensor for highly sensitive detection of 8-hydroxy-2′-deoxyguanosine based on carbon quantum dot coated Au/SiO2 core–shell nanoparticles

• Published in: Talanta (Oxford) Vol. 131; pp. 379 - 385
• Main Authors: Zhang, Ting-Ting, Zhao, Hui-Min, Fan, Xin-Fei, Chen, Shuo, Quan, Xie
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2015
• Subjects: 8-hydroxy-2′-deoxyguanosine; Animals; Biosensing Techniques - methods; Carbon - chemistry; Carbon quantum dot; Core–shell nanoparticle; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - analysis; Electrochemical Techniques - methods; Electrochemiluminescence immnuosensor; Gold - chemistry; Humans; Immunoassay - methods; Limit of Detection; Metal Nanoparticles - chemistry; Milk - chemistry; Quantum Dots; Rabbits; Silicon Dioxide - chemistry; 8-hydroxy-2′-deoxyguanosine; Carbon quantum dot; Core–shell nanoparticle; Electrochemiluminescence immnuosensor
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2014.08.024

An electrochemiluminescence (ECL) immunosensor using Pt electrode modified with carbon quantum dot (CQDs) coated Au/SiO2 core–shell nanoparticles was proposed for sensitive detection of 8-hydroxy-2′-deoxyguanosine (8-OHdG) in this work. Rabbit anti-8-OHdG antibody was covalently bound to CQDs on the surface of Au/SiO2 core–shell nanoparticles. Through signal amplification of Au/SiO2 core–shell nanoparticles, 8-fold enhancement of the ECL signals was achieved. Under optimal conditions, a good linear range from 0.2 to 200ngmL−1 with a low detection limit of 0.085ngmL−1 (S/N=3) for 8-OHdG detection was obtained. Interfering substances tests showed that the corresponding ECL intensity (ΔECL) of 8-OHdG is 8–18 times higher than that of guanine, uric acid (UA) and ascorbic acid, demonstrating its good selectivity for 8-OHdG detection. The ECL immnuosensor exhibits long-term stability with a relative standard deviation (RSD) of 8.5% even after 16 cycles of continuous potential scans. The result of analytical detection of 8-OHdG in real samples was satisfactory. The proposed ECL immnuosensor shows good performance with high sensitivity, specificity, repeatability, stability and provided a powerful tool for 8-OHdG monitoring in clinical samples. A rapid, and highly sensitive electrochemiluminescence immunosensor based on carbon quantum dot coated Au/SiO2 core–shell nanoparticles is presented for 8-hydroxy-2′-deoxyguanosine detection. [Display omitted] ●An ECL sensor was constructed by Au/SiO2/CQDs NPs modified Pt electrode.●This ECL sensor was used for sensitive detection of 8-OHdG.●The ECL intensity of Pt/Au/SiO2/CQDs was 8 times as high as that of Pt/CQDs.●The ECL sensor displayed a high sensitivity, excellent selectivity.