The Design And Applications Of Novel Rhodamine Fluorescence Derivatives Probes

Functional fluorescent probe has attracted much attention in specific environments due to their high sensitivity and specificity.Because of its structure conjugation and elimination with fluorescence quenching or recovery and specific color changes,that can be observed by the naked eyes,xanthene is widely used in a series of environments.Therefore,it is very important to construct a new xanthenes-based fluorescent probe and explore its applications in ion detection area.Based on the structure modification principle of fluorescent probe and recognition mechanism,different groups were introduced into xanthene to form the rhodamine derivatives with different optical properties.Three new rhodamine derivatives fluorescent probes named RB,RBg and RCya,were synthesized by connecting xanthene and aldehydes with hydrazide bond.Different aldehyde group as identification part,they could specifically identify Cu2+、Cu+and Pd2+ in multi-conditions.Mixing small molecular probes with macromolecular polymers,multifunctional sensors for real-time monitoring were developed by electrostatic spinning.1.According to ESIPT,benzothiazole group was attached to the benzene ring on oxyanthracene to compose rhodamine derivative,and 2-pyridyl-formaldehyde was introduced into the lactam loop to synthesize probe RB.The results of optical response experiment indicated that the probe RB can recognize Cu2+/ATP ratioly and reversibly.The molecular structure of probe RB before and after the reaction with the Cu2+and the detection mechanism was simulated and calculated with Gaussian 09 program.On the basis of its superior fluorescence characteristics,the probe RB-PMMA composited nanofiber was prepared by electrospinning,which could visually detect Cu2+ and ATP in multi-enviroments.It indicated that the probe-nanofiber had a good prospect for Cu2+/ATP monitoring.Moreover,the probe RB can detect Cu2+in HeLa cells and successfully perform fluorescence imaging,which showing that it had a promising prospect in biological application.2.Under the ESIPT,the fluorescent probe RBg was designed with amide bonds as connecting group and glyoxal as identifying group on benzothiazole-oxanthracene structure.Furthermore,the optical response of fluorescence probe RBg to Cu+ and its linear relationship with Cu+ concentration(0.0-40.0 μM)were investigated.To prove the good optical properties of probe RBg,dynamic tests were carried out to explore the ion detection sensitivity.Also exploring its optical character in different pH environments.RBg-doped PVDF nanofiber and test strips were used to study the detection effect of probe RBg.The rhodamine fluorescent probe RBg had a broad research and application prospect.3.On the basis of PET,introducing 2,4-dihydroxybenzaldehyde into the lactam screw ring as recognition group,a near infrared fluorescent probe RCya was synthesized,which could detect the Pd2+ rapidly and sensitively in the near infrared region(λmax=735nm).Theoretical analysis and simulation calculation was used to analyze the structure of molecules in the photo-luminescence process by the Density Functional Theory and the detection mechanism was studied.Based on good optical properties of the probe,the fluorescence imaging of Pd2+using probe RCya in HeLa cells was investigated.More importantly,RCya-doped-PAN nanofiber was electrospinned to achieve solid phase detection of Pd2+.Therefore,the probe has a good practical application value in biology and environment.