Synthesis Of Ferrocene Naphthyridine Derivatives And The Study Of Molecule Recognition

Due to the existence of two diendocyclic nitrogen-atoms,1,8-naphthyridine derivatives were widely applied in the areas of nucleic acid molecular recognition and metal ions recognition. The nuclcotidc acid recognition of1,8-naphthyridine derivatives had been investigated in our previous work. Here, in order to develop a simple electrochemical assaying approach with label-free to detect the specific nuclcic acid sequences, the new double functional probes (FecNCD1and FecNCD2), which contain recognition domain (naphthyridine derivative) and electroactive center (ferrocenyl group), were synthesized and applied in nucleotide acid recognition electrochemically. The recognition between ferrocenyl-naphthyridine derivatives and metal ion were studied preliminarily.The main contents of the thesis are summarized as follow:1) A new double functional probe (FecNCD1) was synthesized successfully by condensation of ferrocene aldehyde and naphthyridine derivatives (NCD). The double functional probe exhibited not only the excellent electrochemical response devoted from ferrocenyl but also high selective for G-G mismatch duplex by melting temperature, circular dichroismic spectra (CD) and electrochemical investigation. The electrochemical investigation showed that FecNCD1possessed good selectivity electrochemically to GG mismatch duplex with electrochemical signal "off’, which can be detected directly by naked Au electrode. The electrochemical approach might provide a simple, versatile and low-cost way to detect single nucleotide polymorphisms, which could be found extensive applications in the diagnosis of the genetic diseases.2) Another new double functional electrochemical probe, FecNCD2with the longer linker as compared to FecNCD1, was designed and synthesized in order to develop a simple electrochemical assaying approach with label-free to detect CGG trinucleotide repeat. Circular dichroismic spectra (CD) indicated that FecNCD2with the longer linker exhibited excellent selectivity to CGG trinucleotide repeat. Electrochemical studies indicated that CGG repeat modified electrode had an electrochemical signal selectively among different trinucleotide repeat modified electrodes after incubation with FecNCD2solution. Importantly, using the excellent selectivity electrochemically, CGG trinucleotide repeat biosensor, which was directly utilized to detect free-label trinucleode repeats in solution, was constructed through the competition law. The results showed that CGG trinucleotide repeat biosensor possessed good selectivity for CGG repeats with signal decrease electrochemically in presence of FecNCD2, even with interference ct-DNA. The novel double functional electrochemical probe might provide a versatile and low-cost way to detect trinucleotide repeat, which could be found to be associated with the neurodegenerative diseases. The strategy has significant potential in the development of conceptually new biosensor and for early diagnostic and treatment of diseases.3) The new ferrocene derivatives (FecMN and FecDN) was designed and synthesized. Their interactions with metal ion were investigated by the visual method, electrochemical method, UV-vis absorption spectra, IR and energy dispersive X-ray spectroscopy (EDX) method. The results indicated that FecDN had good recognition to Hg2+with obvious yellow precipitation, which can be seen by naked eyes. FecDN might interact with Hg2+about1:1mole ratio to presumably forme macromolecular mercury complex according to electrochemical titration and EDX analysis. The study would provide a feasible method for identification and removal of mercury ion, which was a very important significance to environmental pollution and human health.