Fluorescent "keep-on" type pharmacophore obtained from dynamic combinatorial library of Schiff bases

We established a novel principle for fluorescence detection of a target protein. A low-molecular-weight fluorescent pharmacophore, as a targeted probe, was selected from a dynamic combinatorial library of Schiff bases. The pharmacophore retains its fluorescence when bound to the hydrophobic site of the target, whereas it loses it because of hydrolysis when unbound. Graphical abstract We describe a novel concept for detection of a target protein (i.e., HSA) by using a keep-on-type fluorescent pharmacophore which is discovered from a dynamic combinatorial library of Schiff bases. When the target is absent, the keep-on-pharmacophore is degraded by hydrolysis, with the result that we can see no fluorescence.