Chiral Nanographene-Based Near-Infrared Fluorophore with Self-Blinking Properties

Abstract

Near-infrared (NIR) fluorophores are highly desirable for super-resolution fluorescence microscopy; however, their optical properties are typically relatively poor, with low photo-intensity (mean photon number below 1000), and unfavorably high on-off blinking duty cycle. In this work, the synthesis and characterization of tetrabenzodinaphthopyranthren (TBDNP) derivative as a novel nanographene that exhibits NIR emission in the range of 800–1000 nm with a photoluminescence quantum yield of 14% are reported. TBDNP demonstrated excellent self-blinking properties, in particular, mean photon number of >3000 and a low on–off-duty cycle (≈10−4), which are superior to reported NIR dyes, and can be successfully employed for the NIR super-resolution imaging. Moreover, TBDNP serves also as a chiral fluorophore, showing notable chiroptical activities from 300 to 850 nm with a high dissymmetry factor (gabs) of 0.032 at 574 nm.