Design,Synthesis And Application Of PH,Hydrazine Fluorescent Probes

Rencently,fluorescent probes and sensors have been utilized to detect analytes in organisms and environments for many advantages,such as high selectivity,high sensitivity,short response time,and simple operation.Intracellular pH has a great influence on physiological function,so more and more attention has been paid to the design of pH fluorescent sensors.Hydrazine is widely used in various industries,however,it is also classified as possible cancer-causing environmental contaminants.Therefore,detection methods toward hydrazine in environmental and biological systems are highly needed.Accordingly,in this thesis,two pH ratio fluorescence sensors and two hydrazine fluorescent probes were synthesized.The main work in this thesis are as follows:1.Based on 1,8-naphthalimde derivatives and carbon quantum dots(CDs),two novel pH ratiometric fluorescence sensors were fabricated for sensing acidic pH.Increasing of pH resulted in complete fluorescammonium salt for bioanalytical applications[J].Spectrochim.Acta,Part A,2015,151:ence quenching of the 1,8-naphthalimide derivatives(527 nm),while the blue fluorescence of CDs(455 nm)keeped constant.The emission intensity increasing at 527 nm in acidic solution could be ascribed to the inhibition of photo induced electron transfer(PET)process.The apparent pKa was determined to be 6.47±0.22 and 6.28±0.17 for 1-CDs and 1-CDs-Lyso,respectively.Furthermore,the CDs-organic molecular sensors exhibited excellent anti-disturbance ability,reversible pH sensing ability,and a linear response range in wide pH range respectively.Besides the ability to target lysosome,with the sensor of 1-CDs-Lys,stimulated pH change has been successfully tracked in a ratiometric manner via fluorescence imaging.2.Hydrazine probe L was synthesized from 1,8-naphthalimide derivatives and 4-(Diethylamino)salicylaminobenzaldehyde.Upon addition of hydrazine,the fluorescence intensity of L at 517 nm was greatly enhanced and showed linear response to the concentration of hydrazine over a wide range(0-20 ?M).The detection limit of hydrazine was 140 nM.Selectivity experiments proved that L had excellent selectivity to hydrazine over other molecules,metal ions,anions and bio-related molecules.Furthermore,cell cytotoxicity and bio-imaging studies revealed that probe L was cell-permeable and could be used to detect hydrazine in living cells with low cytotoxicity.3.A novel ratiometric and on-off fluorescent probe N was synthesized from 4-(Diethylamino)salicylaminobenzaldehyde and 1,1,2-Trimethyl-1 H-benz[e]indole.The probe responded hydrazine and exhibited distinct color changes from blue to pale yellow.The probe N showed selectivity and anti-interference ability towards hydrazine over other molecules,metal ions,anions and bio-related molecules.In addition,the probe exhibited a good linear relationship between the ratiometric fluorescence enhancement and hydrazine concentration in range of 0-400?M and the limit detection could be as low as 560 nM.