Accurate Fluorescence Diagnosis of Cancer Based on Sequential Detection of Hydrogen Sulfide and pH.

Cancer ranks as a leading cause of death in every country of the world. However, if they are discovered early, a lot of cancers can be prevented or cured. Discovering and monitoring cancer markers are the main methods for early diagnosis of cancer. To date, many fluorescent probes designed and used for early cancer diagnosis can only react with a single marker, which always causes insufficient accuracy in complex systems. Herein, a novel near-infrared (NIR) fluorescent probe (CyO-DNP) for the sequential detection of H2S and H+ is synthesized. In this probe, a heptamethine dye is selected as the fluorophore and a 2,4-dinitrophenyl (DNP) ether is chosen as recognition group. In the presence of H2S, CyO-DNP is transformed into CyO, which exhibits an intense fluorescence at 663 nm. Then, H+ induces the protonation of CyO to obtain CyOH, and the final fluorescence emission at 793 nm significantly enhances. Owing to the low cytotoxicity and the NIR fluorescence emission, CyO-DNP can sequentially monitor endogenous H2S and H+ in cancer cells and image exogenous and endogenous H2S and H+ in mice. It is worth mentioning that CyO-DNP can effectively avoid the false positive signal caused by the liver and kidney and discriminate normal mice and tumor mice accurately. For all we know, CyO-DNP is the first fluorescent probe for early accurate diagnosis of cancer by sequentially detecting H2S and H+.

Novel near-infrared fluorescence probe with large Stokes shift for monitoring CCl4-induced toxic hepatitis.

Toxic hepatitis which is induced by chemical substance is a serious threat to human health. More and more studies have shown that peroxynitrite (ONOO-) is related with the development of toxic hepatitis. So it is important to find a tool to study ONOO- change during the diagnosis and therapy of toxic hepatitis. Herein, a series of novel near-infrared (NIR) fluorescence dyes (DDM-R) with long emission wavelength (740-770 nm) and large Stokes shift (~200 nm) are developed. Among the dyes, DDM-OH with great spectral performance and facilely modified feature is used to construct probe DDM-ONOO-. The probe have the preference of high sensitivity and excellent selectivity for ONOO-. In addition, DDM-ONOO- was applied in detecting exogenous and endogenous ONOO- in cells and further used in detecting ONOO- of CCl4-induced toxic hepatitis in cells by fluorescence imaging, 3D quantification analysis, flow cytometry. More importantly, by visualizing ONOO-, the probe was used to monitor the diagnosis of CCl4-induced toxic hepatitis in mice and evaluate the therapeutic efficacy of hepatoprotective medicines (NAC, SM, DDB). The results show that the probe will provide a powerful tool for the diagnosis and treatment of toxic hepatitis.

A near-infrared fluorescent probe for accurately diagnosing cancer by sequential detection of cysteine and H.

A near-infrared fluorescent probe, CyAc, is synthesized for accurately diagnosing cancer in vivo by sequential detection of Cys and H+. CyAc can not only achieve a good distinction between normal cells and cancer cells, but also distinguish normal mice from tumor mice.