Synthesis Of Water-soluble Polydiimide Derivatives And Their Sensing Property

Perylene diimide and naphthalene imide derivatives as typical of fused ring aromatic compounds,because of it contains large p electronic system,which cause high extinction coefficient,high fluorescence quantum yields?FQYs?,a broad color range,and good thermal stability,corrosion resistance and other excellent properties,making them has been widely used in many fields.Such as photostability and electronic.However,this kind of compounds exhibit poor water solubility,which greatly limits its application in the field of chemical or biological sensing.Using its unique optical and electrical properties and improve the water solubility,to construct a kind of high sensitivity and high selectivity of the sensor system is a hotspot of current research.Iron is the most abundant transition metal in the human body.The high concentration of Fe³⁺ is related to the incidence of certain cancers,such as Parkinson's disease,Alzheimer's disease and other neurological disorders.And is closely related to the functional disorders of the heart,liver and pancreas.Therefore,it is of great significance to detect the Fe³⁺ content in the environment or the human body in a timely manner.In addition to DNA is the carrier of genetic information and it shoulders the mission of genetic information.In this paper,we use the alcohols and halogenated compounds polycondensation synthesis of the two kinds of water soluble polydiimide derivatives PDI and NDI,which have good water solubility,and the sensitive fluorescence detection of Fe³⁺ and DNA in pure water system was realized.Specific research contents and conclusions are as follows:?1?The synthesis and characterization of water-soluble polydiimide derivative PDI and NDI.We use the polycondensation method to synthesis of the two kinds of polydiimide derivatives.And by nuclear magnetic resonance spectroscopy?NMR?,time of flight mass spectrometry?MS-TOF?,infrared spectrum?IR?for their chemical structures were characterized and confirmed.?2?Study on the sensing properties of PDI on Fe³⁺.The structure of polyperylene diimide derivatives PDI is using the backbone of perylene imide structure unit as a fluorescence reporting group;and the side chain of terpyridine group?tpy?as the recognition site.When the fluorescent probe is not binding Fe³⁺,due to the PET of tpy to perylene bisimide,makes probe fluorescence quenched,and once tpy combined with Fe³⁺ and PET process is blocked,the fluorescent probe is restored.So the quantitative detection of Fe³⁺ can be realized.The probe showed good selectivity for Fe³⁺ in water,and the binding constant between them was as high as 1.32 × 108 M-2.And the Job's-plot results showed that the two was 1: 2 of the model.In the range of 0-16 ?M,the fluorescence intensity of the probe has a good linear relationship with the concentration of Fe³⁺,the detection limit is about 9.20 × 10-7 M.?3?Study on the sensing properties of NDI on DNA.The side chains of the polyimide derivatives NDI have positive charges,which can be combined with the negatively charged DNA by electrostatic interaction.NDI/DNA complexes of the form,leading to changes in the conformation of NDI,and conduct the the ?-? stacking of NDI polymer chain,to enhance further the formation of large aggregates.Under the DNA induced,the probe NDI shows a obvious fluorescence quenching,and realized the sensitive detection of DNA.In HEPES?0.05 mM,pH = 7.4?buffer solution,the UV-Vis spectra titration showed that the binding constant of NDI and DNA was 1.18×104 M-1.In the range of 20-36 ?M,the fluorescence intensity of the probe has a good linear relationship with the concentration of DNA,and the quenching constant is Ksv = 1.01×107 M-1.And a preliminary study on the detection of DNA activity of the probe was also explored.