Application And Construction Of Multi-Chromophores FRET System Based On BODIPY Fluorophore

Fluorescence resonance energy transfer (FRET) plays an important part in the design of fluorescent dyes and has become an essential bridge connecting organic chemistry and other fields. In the system based on FRET, the most importment part is the selectivity of donor and acceptor. In this paper, a few systems based on FRET were designed and synthesized, which adopted BODIPY fluorophore as donor or acceptor due to its excellent photophysical and photochemical properties.1. A series of light harvesting systems based on BODIPY derivatives were designed and synthesized. Among them, light harvesting system A11 first realized the combination of three kinds of BODIPY derivatives with different wavelengths. It has strong absorption covering 300-700 nm. Furthermore, the energy transfer efficiency from donor to acceptor can arrive to 99%. The introduction of "Click" chemistry simplied the difficulty of synthesis and made its application possible.2. Building two kinds of FRET systems BRB and BR6G with BODIPY as donor (Rhodamine 6G and Rhodamine B as acceptor respectively) and inspecting their application. BRB and BR6G can realize FRET from "off to "on" through an irreversible Hg²⁺-promoted oxadiazole forming reaction of leuco Rhodamine derivatives. In the normal physiological conditions, BRB and BR6G showed highly selectivity and sensitivity for mercury ions. After detecting mercury ions, maximum fluorescence-emission made blue shift about 46 nm and 75 nm respectively. Meanwhile, fluorescent color changed from green to red and yellow respectively, which was readily detectable visually. One thing worthy of note is that the detection limit of BRB is at the parts per billion level, which can satisfy the requirement of Environmental Protection Agency (EPA). Fluorescent imaging experiments in animal cells show that BRB and BR6G can realize the fluorescent ratio detection of mercury ions.3. Fluorescent probe C6 for pH based on 1, 8-naphthalimide and BODIPY derivatives was designed and synthesized. It can realize pH detection in 2.07 - 3.68. Furthermore, stoke shift can arrive to 200 nm and fluorescence quantum efficiency can icrease 23 times as much. It indicated that fluorescent ratio detection of pH through change of overlapping spectra was possible.