Synthesis And Application Of Several Novel Hydrazine Fluorescent Probes

The sensing mechanism and properties of small-molecule fluorescent probe paly an important role in its development,and its response mechanism would influence the selectivity and sensitivity of probe in complicated samples,directly.Therefore,discovering and studying a new response mechanism is an important part in the development of small-molecule fluorescent probe.In the paper,the discovery of new mechanism and research of probe properties were discussed,and three different kinds of small-molecule fluorescent probe were designed and synthesized to detect hydrazine,with the detailed discussion of response mechanism.(1)The near-infrared fluorescence probe(E)-2-(2-(3-formyl-4-hydroxystyryl)-4H-chromen-4-ylidene)malononitrile(DCM2)was designed and synthesized,based on two-site response.The condensation reaction of aldehyde group and malononitrile of probe with hydrazide occurred,accompanied by fluoscence quenching caused by the interrupted intracellular charge transfer.The probe can detect hydrazine with high selectivity and sensitivity,and the clear color change proved the possibility of naked-eye detection of hydrazine.In addition,the near-infrared showed a low background in cell imaging,and successfully applied to image different concentrations of hydrazine in living cells.(2)The selection of unsaturated carbonyl groups as recognition unite,and the use of intermolecular hydrogen bond force for activation can accelerate the reaction between the probe and hydrazine.Thus,the fluorescence probe 2'-hydroxyacetophenone derivatives(P-OH)and control probe acetophenone derivatives(P-H)were designed and synthesized.Compared with P-H,intermolecular hydrogen bonds play an important role in the reaction of P-OH with hydrazine.The specific response mechanism of P-OH was proved in detail by 'H NMR and mass spectrometry.P-OH can detect hydrazine with not only good colorimetric and ratiometric response,but slao high selectivity.More importantly,P-OH can be used for the detection of tracing hydrazine in actual water samples and the imaging study of hydrazine in living cells(3)Based on the strongly electronic ability of diaminomaleonitrile and good dyeing properties of its derivatives,a admirable colorimetric and ratiometric fluorescent probe diaminomaleonitrile derivatives(DHM)was designed and synthesized for the detection of hydrazine.Upon addition of hydrazine,the effect of the charge transfer(ICT)in the molecule disappeared,and the blue shift of fluorescence emission occured,caused by the strong ability to pull electrons of DHM.Meanwhile,the obvious color change from purple to yellow can be easily observed.Furthermore,DHM was successfully used to detect trace hydrazine in real water sample.