Signal Amplification Strategy Using Atomically Gold-Supported VO Nanobelts as a Co-reaction Accelerator for Ultrasensitive Electrochemiluminescent Sensor Construction Based on the Resonance Energy Transfer Platform.

Luminol, as a classical luminophore, plays a crucial role in electrochemiluminescence (ECL). However, the traditional luminol-HO ECL system suffers from the self-decomposition of HO at ambient temperature, which hinders its further application in quantitative analysis. In this work, for the first time, we developed atomically gold-supported two-dimensional VO nanobelts (Au/VO) as an advanced co-reaction promoter to speed up the reduction of dissolved oxygen to superoxide radicals (O), which react with the luminol anion radical and greatly promote the ECL emission. The ECL resonance energy transfer (ECL-RET) between the hollow manganese dioxide nanospheres and luminol results in a conspicuously decreased ECL signal response, and in the presence of glutathione (GSH), effective redox reaction between manganese dioxide and GSH restores the ECL signal. As a consequence, the designed sensor based on ECL-RET-assisted Au/VO signal amplification showed outstanding performance for "signal-on" detection of GSH in the concentration range of 10 to 10 M, and the detection limit was as low as 0.03 nM. The ECL sensor displayed excellent specificity and was successfully utilized to target GSH in real human serum samples. Importantly, this work not only highlights a powerful avenue for constructing an ultrasensitive ECL sensor for GSH but also provides some inspiration for the further design of high-performance co-reaction accelerators using the ECL technique.