Electrochemiluminescence detection for β-amyloid1-42 oligomers using silver nanoparticle decorated CuS@CoS2 double shelled nanoboxes as dual-quencher

Abstract

A highly effective dual-quenching electrochemiluminescence (ECL) immunosensor premised on the electrochemiluminescence resonance energy transfer (ECL-RET) was constructed using silver nanoparticle decorated CuS@CoS2 double shelled nanoboxes (CuS@CoS2 DSNBs@Ag NPs) as the ECL acceptor and gold nanoparticles functionalized carbon nitride (Au@C3N4) composites as the ECL donor. Generally, the UV–vis absorption spectra of CuS@CoS2 DSNBs@Ag NPs were found effectively overlapped with the ECL spectra of Au@C3N4 composites to trigger dual-quenching process. The fabricated Au@C3N4 composites were also served as substrate to immobilize primary antibody (Ab1) via Au-N bond besides providing excellent ECL signal sources. Moreover, CuS@CoS2 DSNBs@Ag NPs can capture the secondary antibody (Ab2) via the Ag-N bond to complete the sandwich immune interaction, where the ECL emission of Au@C3N4 composites were flexibly regulated by CuS@CoS2 DSNBs@Ag NPs via dual-quenching to indicate the concentration information of the detected antigens. This established immunosensor represented eminent performance for β-amyloid1−42 oligomers (Aβ) detection in a wider detection range of 0.5 pg/mL-20 ng/mL with a much low detection limit of 0.0038 pg/mL (S/N = 3). With high sensitivity and good specificity features, the expected ECL strategy paved a latest pathway to perceive a persuable sensitive detection of Aβ.