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

Abstract

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 200 ng mL(-1) with a low detection limit of 0.085 ng mL(-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 immunosensor 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 immunosensor shows good performance with high sensitivity, specificity, repeatability, stability and provided a powerful tool for 8-OHdG monitoring in clinical samples.

Carbon Based Dots and Their Luminescent Properties and Analytical Applications

“…Then the first coreactant ECL system about CDs has been developed. Up to now, the coreactant ECL of CD-S 2 O 8 2− system has been well studied and used in sensors [57,121,[213][214][215][216][217][218][219]. Besides S 2 O 8 2− , SO 3 2− and L-cysteine (L-Cys) were subsequently found to be able to enhance the cathodic ECL signal of CDs [211,212].…”

“…The developed signal on ECL aptamer sensor exhibited excellent analytical performance for ATP determination, ranging from 5.0 × 10 −12 to 5.0 × 10 −9 mol L −1 with the detection limit of 1.5 × 10 −9 mol L −1 . Zhang et al immobilized carboxyl groups-containing CDs on the surface of amine-functionalized Au/SiO 2 core-shell nanoparticles to form Au/SiO 2 /CDs hybrid, which was easily to be immobilized on the electrode surface, producing strong ECL signal in the presence of S 2 O 8 2− [213]. The ECL intensity would be decreased as the electron transfer on the electrode surface was hinder.…”

An Electrochemiluminescent Biosensor Based on Interactions between a Graphene Quantum Dot−Sulfite Co‐reactant System and Hydrogen Peroxide

“…[8,[10][11][12] For examples, the GQDs/S 2 O 8 2À system has been used for metal ion sensing, [10,13] DNA detection, [14] and immunoassay. [15,16] The lack of ECL co-reactants may seriously limit the sensing applications of the new and promising ECL nanomaterials.…”

The synthesis of Ag@CQDs composite and its electrochemiluminescence application for the highly selective and sensitive detection of chloride

“…Compared to the conventional electrochemical and chemiluminescence techniques, the ECL method was more promising because of its high sensitivity, good controllability, and extended response range [14,15]. In recent years, a series of semiconductor nanocrystals, known as quantum dots (QDs), have been reported to have ECL emission properties [16], promising for the construction of ECL biosensors [17].…”