RuSiO₂@Ag Core–Shell Nanoparticles for Plasmon Resonance Energy Transfer-Based Electrochemiluminescence Sensing of Glucose and Adenosine Triphosphate

Convenient and fast approaches for sensitive monitoring of different biomolecules are of vital importance for obtaining insights into biological processes and related diseases. Herein, silica nanospheres encapsulated with Ru(bpy)32+ (RuSiO2) were uniformly coated with silver nanoparticles (AgNPs) through the in-situ reduction method to form RuSiO2@Ag core–shell nanoparticles, which were employed to fabricate a versatile electrochemiluminescence (ECL) sensing system for the assay of glucose (Glu) and adenosine triphosphate (ATP) on the basis of ECL resonance energy transfer (ECL-RET). RuSiO2@Ag core–shell nanoparticles showed high RET efficiency due to the combination of the donor (RuSiO2)–acceptor (AgNPs) pair into one nanostructure, causing a significantly quenched ECL signal of RuSiO2. Afterward, the Glu oxidase immobilized on RuSiO2@Ag by DNA complementation naturally catalyzed the oxidation of Glu to produce H2O2, which then triggered the etching of AgNPs. Consequently, the remarkably recovered ECL signal was further used to specifically detect Glu and achieved a limit of detection of 0.15 μM. ATP was chosen as a model molecule to verify the detecting ability of the sensor and achieved femtomolar-level results. The versatile ECL sensing system based on enzymatic oxydate-triggered etching and RET strategies hold potential promise for the convenient and sensitive detection of multiple types of biomolecules.