Sensitive Insulin Detection based on Electrogenerated Chemiluminescence Resonance Energy Transfer between Ru(bpy)(3)(2+) and Au Nanoparticle-Doped beta-Cyclodextrin-Pb (II) Metal-Organic Framework

摘要

A novel sandwich-type electrochemiluminescent (ECL) biosensor based on ECL resonance energy transfer (RET) was developed for the determination of insulin. Au nanoparticle-doped Pb(II)-beta-cydodextrin (Pb-beta-CD) metal-organic framework was exploited as an ECL donor and chitosan/Ru(bpy)(3)(2+)/silica nanoparticles (CRuSi NPs) were employed as ECL acceptor. Pb-beta-CD shows excellent ECL behavior and unexpected reducing ability toward AuCl4-. Au nanoparticles could massively form on the surface of Pb-beta-CD (Au@Pb-beta-CD) without use of any additional reducing agent. In the presence of co-reactant K2S2O8, the ECL emission of Pb-beta-CD was enhanced by the formation of Au nanoparticles, which is desirable for the construction of a RET immunosensor. The absorption spectra great overlaps with the ECL spectra of Pb-beta-CD. This enabled the ECL-RET by incorporating Au@Pb-beta-CD and CRuSi NPs into electrode surfaces. The immunosensor is fabricated using Au@Pb-beta-CD as sensing platform and CRuSi NPs as labels of antibodies. After the optimization of determination conditions, a linear response range for insulin from 0.1 pg mL(-1) to 10.0 ng mL(-1) was obtained, and the limit of detection was calculated to be 0.042 pg mL(-1) (S/N = 3). The prepared insulin biosensor displayed excellent stability and good specificity.