Multimode sensing and imaging platform for versatile detection of GSH based on surface modification strategy of Ru(bpy)32+ doped SiO2 nanoparticles

A multimode sensing and imaging platform based on surface modification strategy of Ru(bpy)32+ doped SiO2 nanoparticles (RuSiO2 NPs) was constructed for versatile detection of glutathione (GSH). RuSiO2 NPs as the luminophore models had outstanding fluorescence (FL) and electrochemiluminescence (ECL) signals. Furthermore, its FL signal could be captured by electrophoresis analyzer, and the ECL signal could be imaged with mobile phone to achieve visualization. So, a unique and convenient multi-mode sensing and imaging platform could be developed based on RuSiO2 NPs. SiO2 NPs could realize enrichment of Ru(bpy)32+ based on the nanoconfined effect to achieve signal amplification, and its surface was rich with abundant hydroxyl functional groups, which offered a channel for surface modification. Sulfhydryl modification on the RuSiO2 NPs was realized by using silane coupling agent, and KMnO4 was used to in situ generate MnO2 shell on the surface of RuSiO2 NPs for quenching its ECL, FL, and colorimetric (CL) signals based on resonance energy transfer (RET). Target GSH could reduce MnO2 shell to realize recovery of all signals, thus achieving the label-free multimode detection of GSH. Therefore, this work developed a multimode sensing and imaging platform without signal labels or layer-by-layer assembly of electrodes, which had the advantages of simple steps, low cost, and high detection accuracy, showing important application potential in the field of bioanalysis.