Signal Amplification Strategy Using Atomically Gold-Supported VO2 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-H2O2 ECL system suffers from the self-decomposition of H2O2 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 VO2 nanobelts (Au/VO2) as an advanced co-reaction promoter to speed up the reduction of dissolved oxygen to superoxide radicals (O-2(center dot-)), 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/VO2 signal amplification showed outstanding performance for signal-on detection of GSH in the concentration range of 10(-3) to 10(-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.

Automated summary

In this study, gold-supported two-dimensional VO2 nanobelts were developed as co-reaction promoters to enhance the efficiency of luminol ECL emission for sensitive detection of GSH. The ECL sensor showed outstanding performance in real human serum samples, highlighting the potential for high-performance co-reaction accelerators using the ECL technique.