The Preparation And Application Of Etching Based Hydrogen Sulfide Nanoprobes

Hydrogen sulfide?H₂S?,which mediates many physiological processes,has been certified to be a vital reactive sulfur species.However,the abnormity of H₂S levels in cells can cause various diseases,such as Alzheimer's disease,liver cirrhosis,hypertension and Down's syndrome.In order to understand the role of H₂S in physiological processes,it is necessary to develop effective methods to monitor H₂S in biosystems.However,rapid and highly efficient detection of H₂S in biological samples is still a very serious challenge.Therefore,two etching based nanoprobes were constructed for high sensitive detection of H₂S in this thesis.The first part of this thesis is the construction of FAM-DNA/AgNPs nanocomposites,which is used for rapid and sensitive detection of H₂S in cells.H₂S serves as an etching agent to displace the binding sites of nucleic acid bases absorbed on the surface of AgNPs.The fluorescence labeled single-stranded nucleic acid was released from the surface of AgNPs,resulting in fluorescence recovery.Compared with the majority of the reported H₂S probes,simple synthesis procedures,short response time,low detection limit,high sensitivity and selectivity are involved in our probe.This research provides new overview of interaction between H₂S and inorganic nanomaterials,and expands the application of the DNA based biosensors.In the second part,an AuNRs/Ag-DNA plasma nanoprobe was constructed,which is used for rapid and sensitive detection of H₂S.In the presence of H₂S,the silver in AuNRs/Ag-DNA nanoprobe will be etched and converted into Ag₂S.During this produce,Ag₂S is adsorbed on the surface of AuNRs,resulting in surface plasmon resonance?SPR?shifts.However,many components in practical samples absorbe visible light strongly,which easily interfere with the probe.In our work,the SPR peak is located in the NIR region,which makes the plasma nanoprobes more suitable for the detection of real samples.