Etching Triangular Silver Nanoparticles by Self-generated Hydrogen Peroxide to Initiate the Response of an...

This work outlines a versatile and high-performance electrochemiluminescence (ECL) platform that uses complex luminescent molecules [Ru(II) complex] formed by carbohydrazide (CON₄H₆) and tris(4,4'-dicarboxylicacid-2,2'-bipyridyl)ruthenium(II) dichloride [Ru(dcbpy)₃²⁺] as emitters to facilitate the intramolecular ECL mechanism for reducing the response distance and interference, and they were kept immobilized on a porous bismuth vanadate nanoarray (BiVO₄ NA) to improve the orderliness of electron transfer. In addition, the detection was made depending on the etching of triangular silver nanoparticles (T-Ag NPs) by self-generated hydrogen peroxide (H₂O₂) to initiate the recovery response of the originally quenched ECL due to ECL-RET between the Ru(II) complex (donor) and T-Ag NPs (receptor). Because of the antibacterial application of dopamine, its own redox ability could produce more H₂O₂ for etching receptor T-Ag NPs under near-infrared (NIR) stimulation. Notably, in this system, the specific binding of antigens and antibodies with the autogenesis process of H₂O₂ and the ECL detection procedure are independent. Therefore, the proposed system can avert the impact of complex biological samples effectively, and the ECL efficiency of the Ru(II) complex can be readily utilized. On this basis, a biosensor is explored for the primary diagnosis of squamous cell carcinoma by detecting the biomarker named after cytokeratin fragment 19 (CYFRA21-1), from which an excellent linearity from 0.1 pg/mL to 50 ng/mL is achieved with a detection limit of 0.058 pg/mL. All of these results confirmed that this strategy can be a promising candidate for fabricating an ECL-based biosensor.