Spiropyran–Merocyanine Based Photochromic Fluorescent Probes: Design, Synthesis, and Applications

Abstract

Due to ever-increasing insights into their fundamental properties and photochromic behaviors, spiropyran derivatives are still a target of interest for researchers. The interswitching ability of this photochrome between the spiropyran (SP) and merocyanine (MC) isoforms under external stimuli (light, cations, anions, pH etc.) with different spectral properties as well as the protonation–deprotonation of its MC form allows researchers to use it suitably in sensing purposes by developing different colorimetric and fluorometric probes. Selective and sensitive recognition can be achieved by little modification of its SP moiety and functional groups. In this review, we emphasize the recent advancements (from 2019 to 2022) of spiropyran–merocyanine based fluorogenic and chromogenic probes for selective detection of various metal ions, anions, neutral analytes, and pH. We precisely explain their design strategies, sensing mechanisms, and biological and environmental applications. This review may accelerate the improvements in designing more advanced probes with innovative applications in the near future.

Ligand-protected nanocluster-mediated photoswitchable fluorescent nanoprobes towards dual-color cellular imaging

“…Upon irradiation by UV light at 365 nm, the solution gradually became red uorescent originating from the MC state of spiropyran as expected. 50,51 Meanwhile, the green uorescence of AuNCs was effectively inhibited due to the energy transfer from AuNCs to the MC state of spiropyran. Indeed, the uorescence spectra of DPF NPs exhibited signicant changes upon UV light irradiation, as shown in Fig.…”

Advances and Trends of Photoresponsive Hydrogels for Bone Tissue Engineering

“…Additionally, we have elucidated the responsive mechanism of representative compounds in Table and Figure . Our goal is to provide new research insights for scaffold design in BTE through an analysis of different material responsiveness. − …”

Photochromic and Luminescent Properties of a Salt of a Hybrid Molecule Based on C60 Fullerene and Spiropyran—A Promising Approach to the Creation of Anticancer Drugs

“…This assumption is supported by the fact that, owing to high lipophilicity of the fullerene cage, hybrid molecules rapidly penetrate cell membranes, thus accessing cell organelles, which opens the way to the design of targeted drug delivery systems [ 15 , 16 , 17 ]. Moreover, given the fact that in recent years the popularity of using spiropyrans as vectors for targeted drug delivery has increased, this idea looks quite realistic [ 18 , 19 , 20 ]. Besides, the luminescent properties of merocyanine forms of C 60 derivatives would allow not only visualization of the route and accumulation of these compounds in particular organelles of the target cells, but also the study of the cytotoxicity mechanisms using various cell lines.…”