A General Strategy for Development of Near‐Infrared Fluorescent Probes for Bioimaging

Abstract

Near-infrared (NIR) fluorescent dyes with favorable photophysical properties are highly useful for bioimaging, but such dyes are still rare. The development of a unique class of NIR dyes via modifying the rhodol scaffold with fused tetrahydroquinoxaline rings is described. These new dyes showed large Stokes shifts (>110 nm). Among them, WR3, WR4, WR5, and WR6 displayed high fluorescence quantum yields and excellent photostability in aqueous solutions. Moreover, their fluorescence properties were tunable by easy modifications on the phenolic hydroxy group. Based on WR6, two NIR fluorescent turn-on probes, WSP-NIR and SeSP-NIR, were devised for the detection of H S. The probe SeSP-NIR was applied in visualizing intracellular H S. These dyes are expected to be useful fluorophore scaffolds in the development of new NIR probes for bioimaging.

An Activatable and Switchable Nanoaggregate Probe for Detecting H2S and Its Application in Mice Brains

“…[13,14] There is not much to debate anymore about the significance on monitoring the internal level of H 2 S, [15][16][17][18] however, when the investigations nowadays come to the tissues or models in vivo, near-infrared (NIR) implements seem more favoured due to the strong penetrability and photothermal/photoacoustic effect. [19] No matter the probes are small molecular or nanoscale ones, [20,21] one major concern is maintaining obvious reporting signals to guarantee both sensitivity and selectivity. Basically, longer wavelength means weaker energy, thus a direct NIR sensing usually need a subsequent procedure of amplification.…”

Selenosulfides Tethered to gem‐Dimethyl Esters: A Robust and Highly Versatile Framework for H2S Probe Development

“…To achieve this desired versatility without comprising reactivity and selectivity, we conjectured that the employment of a selenosulfide functionality would be key for accessing a probe with these desired attributes. Although selenosulfides have been rarely reported within the chemical literature, we reasoned that reactivity differences between selenium and sulfur could be exploited such that the selenium half, when tethered to a second electrophilic partner, would effectively scavenge and detect H 2 S, while the sulfur half would provide a suitable handle for mediating its physicochemical properties. Therefore, we first synthesized selenosulfide 1 from 3‐bromopivalic acid (see the Supporting Information) as it provided an amino group for subsequent conjugation reactions.…”

Far-red pentamethine cyanine dyes as fluorescent probes for the detection of serum albumins

“…It is also worth mentioning the design of a two-photon styryl fluorescent probe for real-time monitoring the changes in the activity of acetylcholinesterase in the brain in vivo [6]. Also, near-infrared (NIR) fluorescent turn-on probes were developed for the detection and visualization intracellular H 2 S [7]. A number of fluorescent dyes for protein determination in solution and monitoring of protein structure modification are already commercially available [8].…”