The Construction Of Photochemical Biosensor And Application For HAV And MicroRNA-122 Biomolecules

Photochemical biosensor are essential tools for real-time analytical sensing of biological molecules and processes in live cells and organisms.Photochemical biosensors have a variety of intrinsic advantages,including high sensitivity,simple instrumentation,and capacity for high-throughput screening.In this paper,three different photochemical biosensors were constructed based on the technique of chain displacement cycling and molecular imprinting and were used to sensitivily and selectively detect of biomolecule hepatitis A virus and miRNA-122.The main research work is as follows:?1?Development of a thermosensitive molecularly imprinted polymer resonance light scattering sensor for detection of hepatitis A virus.In this study,a thermosensitive imprinted polymer coating SiO₂ was developed for a resonance light scattering?RLS?thermosensitive virus-affinity sensor,which exhibited high selectivity for virus monitoring.In this sensor,N-isopropylacrylamide was a temperature-sensitive element.The recognition performance of the nanosensor for viruses was regulated by temperature control for the specific capture of the target virus at 40 °C,resulting in the increase of RLS intensity and its release at 20 °C.Moreover,the RLS intensity of the nanosensor significantly increased within 30 min.Accordingly,a very good detection limit of 1.1 pM was obtained.The nanosensor was successfully used to detect the additional hepatitis A virus from a dilution of human serum,and recoveries in the range of 90.8% to 108.3% were attained at three spiking levels of viruses.Overall,this study addressed the problems of high nonspecific adsorption and long duration of detection process.Furthermore,a facile,rapid,and efficient tool for virus detection was provided.?2?Fluorescent detection of HAV via virus-imprinted SiO₂@MPS-CdTe/CdS microspheres.In this study,using virus as template via a sol-gel process,we developed a novel fluorescent probe for specific recognition detection of hepatitis A virus?HAV?by CdTe/CdS quantum dots?QDs?based silica nanoparticles?Si O₂@MPS-CdTe/CdS@MIPs?.When HAV was present,the photoluminescent energy of QDs would be transferred to the HAV,leading to the fluorescence quenching of QDs.Moreover,the fluorescence intensity of the nanosensor significantly decreased within 20 min.Accordingly,a very good detection limit of 88 pM was obtained.The nanosensor was successfully used to detect the additional hepatitis A virus from a dilution of human serum,and recoveries in the range of 96.7% to 103.8% were attained at three spiking levels of viruses.Overall,this study addressed the problems of long duration of detection process.Furthermore,a facile,rapid,and efficient tool for virus detection was provided.?3?Ratiometric fluorescent biosensor for detection of miRNA-122 based on hybridization chain reactionA novel ratiometric fluorescence sensor based on hybridization chain reaction was constructed for detection of microRNA-122?miRNA-122?by using 2-aminopurine?2-AP?and Thioflavin T?ThT?as detection signal source.With the presence and increase of miRNA-122,the 2-AP transform in the single-stranded DNA into in the double-stranded and thereby the 2-AP fluorescence intensities could be significantly decreased,while the ThT fluorescence intensities could be significantly enhanced since the G-quadruplex sequence in the opened H1 can form a G-quadruplex structure stabilized by K+ ions.As a result,the as-prepared fluorescence sensor obtained high sensitivity with a low detection limit of 72 pM within 80 min,and distinguished recognition selectivity for miRNA-122 over its analogs.Moreover,the sensor was successfully applied to determine miRNA-122 in human cancer cell lysates.The simple,enzyme-free and ratiometric fluorescence strategy would not only enrich the research connotations of microRNAs sensors,but also potentially applied in miRNA-related biochemical research and clinical diagnostics.