Multifunction Fluorescent Probes For Biological Applications:Design, Synthesis And Application

In the present work, based on the mechnism of space-folded photo-induced electron transfer, time-dependent ICT and metal complexs recognition, three kinds of fluorescent probes were desiged and synthesized. The fluorescent probes for the detection of disease targets such as metal ions, amino acids and enzymes, achieved high selectivity and sensitivity.1. We have developed a novel fluorescent probe Z1for directly detection of carbonic anhydrase Ⅸ (CA Ⅸ) against CA Ⅰ and CA Ⅱ with high sensitivity and selectivity. Based on the conversion between boat and chair conformations of piperazidine, Z1was designed and synthesized with space-folder photo-induced electrontransfer (SPET) mechanism. As demonstrated, only CA Ⅸ induced the fluorescence enhancement and the CA Ⅰ and CA Ⅱ induced decrease in fluorescent intensity. Moreover, the fluorescent probe Zl works in both enzymatic systems and in living cells. To our knowledge, this is the first excellent example of "off-on" fluorescent probe selectively for CA Ⅸ.2. A novel fluorescent probe S1, a complex consisted of a naphthalimide-based ratiometric fluorescent probe M2and Cu2+, was designed and synthesized. Among20a-amino acids, S1only responded to histidine with high selectivity and sensitivity in neutral solution. Meanwhile, it was also a colormetric and ratiometric probe for histidine detection. Most importantly, probe S1also can detect the histidine residues on proteins and has potential in imaging histidine in living cells. As with simple synthesis as well as dual response to histidine, our probe S1has excellent potential in rapid and highly sensitive detection.3. We have designed and synthesized a new naphthalimide-based fluorescent probe E3, which displays a ratiometric detection of Co2+and time dependent detection of Cu2+and Ni2+via a1:1binding mode over other metal ions in50mM HEPES/EtOH (v/v:60/40) buffer at pH7.2. As demonstrated, it respectively took5min,30min and150min for Co2+, Cu2+and Ni2+to generate the new fluorescent peak of E3at474nm, which indicated that detection of three metal ions with time dependence was feasible. Besides, the competition experiment showed that the appearance time of new fluorescent peak at474nm for Cu2+and Ni2+changed with Co2+added, but the Cu2+could not induce the appearance time for Ni2+. Thus we colud detect three metal ions (Co2+, Cu2+and Ni2+) and two metal ions combination ([Co2++Ni2+] and [Co2++Cu2+]) with time dependence in same aqueous media.