The Synthesis And Application Of Bodipy-Imidazole Salts

Borondipyrromethene (Bodipy) fluorescent dyes have been recognized as the promising platform for the construction of molecular sensors due to their valuable characteristics, such as sharp absorption and fluorescence emission spectra, intense fluorescence quantum yields, and high photo-and chemostability. In this paper, we have synthesized and evaluated several bodipy-imidazole Salts. We also have demonstrated that Bodipy-imidazolium salts modified with different function group can be exploited as sensitive fluorescent turn-on probes for DNA, and Cu2+, respectively.1. Two Bodipy-imidazolium salts, BODIPY-MS1and BODIPY-MS2, as fluorescence turn-on probes for DNA were developed. Deoxyribonucleic acid (DNA) is an important macromolecule encoding the genetic instructions for the development and functioning of all known living organisms. DNA detection has found widespread applications in molecμLar diagnostics and civil defense, which has motivated intense interest in developing rapid, simple, and cost-effective sensors for DNA. Among them, binding studies of DNA with various small molecules can provide valuable routes toward rational design of efficient drugs targeted to DNA as well as a means to develop sensitive chemical probes of DNA structure. Therefore, the design of novel small molecules for studying the interaction with DNA is on demand and, to some extent, is one of the most important goals in modern medicinal chemistry. The most often used small heterocyclic compounds for DNA are phenanthridine derivatives and the cyanine class of fluorescent dyes. Much less attention was paid to development of alternative new fluorescent intercalators, especially these with substantial increase in fluorescence intensity upon intercalation with DNA. While boron-dipyrromethene (Bodipy) fluorescent dyes have been recognized as the promising platform for the construction of molecμLar probes, no reports have been published concerning Bodipy framework as a planar moiety, one of the important features needed for efficient intercalation with DNA, for studying the binding properties with DNA. In this paper, we attempted to choose Bodipy as a planar aromatic ligand and imidazolium group as a cationic function to achieve a sensitive and selective fluorescent intercalator toward DNA. Extensive photophyscial studies have been exploited to address the nature and the strength of the stacking interaction between BODIPY-MS1or BODIPY-MS2with DNA. It is the intercalative interaction of the Bodipy dyes with DNA that is responsible for the quite remarkable spectroscopic changes of BODIPY-MS1or BODIPY-MS2in the presence of DNA. Strong hypochromism and red-shifted absorption spectra, together with the marked decrease in the positive CD band of ct-DNA, strongly support intercalation of the chromophores. The fluorescence of BODIPY-MS1differs somewhat from that of BODIPY-MS2. In contrast to the nonfluorescent of BODIPY-MS1, BODIPY-MS2gives fluorescence to some degree in aqueous solution. More important, these dyes give substantial increases in fluorescence on DNA binding and may prove useful as sensitive fluorescent turn-on probes for DNA. The intercalative interaction can also be supported by the time-resolved fluorescence studies in which the longer lived excited-state lifetime is observed upon interaction. Cell imaging experiments also confirms that the two DNA intercalators can be used as cell markers and are capable of detection DNA in nucleus of living cells2. Bodipy-imidazole salt Bodipy-MS3bearing a ferrocene function at the a position, showing a specific fluorescence turn-on response to Cu2+in acetonitrile. Furthermore, this probe features excellent selectivity over other competing analytes, enabling the promise for application.