A cyanine-modified upconversion nanoprobe for NIR-excited imaging of endogenous hydrogen peroxide signaling in vivo

Endogenous hydrogen peroxide is an important parameter associated with cellular signal transduction and homeostasis. However, abnormal H2O2 regulation in live systems has been implicated in many pathological conditions. Monitoring this signal in live systems is essential but challenging because current H2O2 probes are impractical for efficient bio-imaging due to UV/visible light as the excitation source. We herein present a novel design based on an organic fluorophore-attached lanthanide-doped upconversion nanoprobe (CYD1-UCNPs) for selective UCL detection of H2O2. This nanoprobe represents the next-generation imaging tool that features a robust UCL "turn-on" response to H2O2 with NIR-excited ratiometric signals and has potential applications in ratiometric UCL imaging of endogenous H2O2 generating in living cells and whole-body animals.