Near-Infrared Ratiometric Two-Photon Probe for pH Measurement in Human Stomach Cancer Tissue.

Stomach cancer is a global health issue because of its incidence and mortality rates worldwide. We developed a near-infrared (NIR) emissive ratiometric two-photon (TP) probe () for the quantitative analysis of pH in live cells and human stomach tissues. The probe design is based on a restrained hemicyanine core that controls the intramolecular charge transfer from 2-naphthol, with a suitable p value (7.