Design of fluorescent sensors for the detection of human serum albumin structure employing nitrogen-by modulation of molecular containing heterocycles

Serum albumin is the most abundant protein in mammalian plasma. It occupies an extremely important position in organisms as an early indicator of the development of many diseases. The development of fluorescence sensing technology has revolutionized the drawbacks of traditional methods. In this strategy, we designed and synthesized three dual fluorophore organic sensors TPA-IPA-T1, TPA-QL-T2, and TPA-Py-T3 for the detection of serum albumin. The rotation of the C–C bond of sensors is restricted and the molecular structure forms a rigid plane that contributes to the fluorescent emission intensity of the sensor. The fluorescent skeletons were successfully constructed by triphenylamine composed the electron-withdrawing nitrogen-containing compounds benzopyrrole (indole), benzopyridine (quinoline), and pyridine, respectively, with piperazine as a rigid connecting bridge. The addition of human serum albumin (HSA) turned on the fluorescent emission of the sensor near 580–600 nm. The color of the sensor solution changed from colorless to pink and bright orange, respectively. The fluorescent intensity increased by 24, 67, and 31 fold, respectively. The sensors have the advantages of sensitivity and fast response, strong anti-interference ability, low detection limit and good water solubility. Drug experiments in artificial urine demonstrate the characteristics of sensors, which has a very high potential for biological feasibility and medical applications. The sensors facilitaty the binding of the HSA through electrostatic interactions. The sensors were explored to be able to efficiently bind the IB structural domain of HSA, which had a good meaningful of avoiding the interference of commonly drugs in clinical medicine and in artificial urine on the detection of HSA.