Study On The Melting Process Of Nucleic Acids Based On Reflection Interference Spectroscopy

Since the sequences of DNA plays an immense role in understanding of life cells and their functions arising from the decoding of genomes.At present,the detection of DNA sequences and oligonucleotide fragments has been widely utilized in many fields such as the medical diagnosis,biological research,and even the food industry monitoring and environmental monitoring.In the detection of DNA sequences,the efficiency of capturing DNA mainly dependent on the oligonucleotide hybridization which can be critically affected by the melting temperature(T_m).To accurately determine the T_m of oligonucleotide hybridization is the most basis and primary for various biosensors based on the technique of using surface-tethered nucleic acids as probes.Many research works based on multifunctional biosensors and microarray transducers for the detection of DNA hybridization have been reported.In this paper,a new type of nano-sensor based on reflection interference spectrum(RIFS)was proposed,and a novel optical detection system was constructed on this basis to study the process of nucleic acid melting.In this research,gold-plated nanoporous anodic alumina membrane(nanoPAAM)was used as the sensor substrate to detect the melting process of DNA molecules.By coupling oligonucleotide molecules with the inner wall of the pores,DNA molecular probes were prepared and uniformly applied by a temperature control device.Based on the self-built system and self-prepared biosensor,the paper studied the melting process of DNA molecules with different base numbers,which indicated the influence of chain length on the melting temperature of DNA molecules.The experimental results are highly consistent with the theoretical data.Besides,the paper further studied the effects of base mismatch and multi base mismatch on the melting process,and established a method for detecting the melting temperature of DNA molecules.A series of tests show the heat stability and physicochemical stability of the nanosensor,and possess huge potential in the field of biomolecules research.