Preparation And Application Of Viral Molecularly Imprinted Sensors Based On Persistent Luminescent Materials

In the past two decades,frequent outbreaks of various viruses have brought immeasurable losses to the world and caused great global panic.Therefore,early and accurate monitoring of the virus has become the key to epidemic prevention.At present,the research on virus detection strategies has entered a diversified and rapid development stage.Among them,fluorescence sensing,as one of the research hotspots in the sensing field,has also been widely studied in virus detection.However,all kinds of auto-fluorescent substances in complex biological samples such as serum will cause huge interference of fluorescence background in practical applications.Here,in order to avoid the interference of autofluorescence in complex biological samples,a kind of autofluorescent-free molecularly imprinted polymer aptasensor（MIP-aptasensor）was designed to detect influenza virus（H5N1）and hepatitis B virus（HBV）by using the luminescence decay effect of persistent luminescent nanoparticles（PLNPs）.The proposed MIP-aptasensor is based on MIP and aptamer-functionalized persistent luminescent nanoparticles,which can simultaneously identify the target virus and yield strong persistent luminous signal change.The designed MIP-aptasensor effectively eliminates the autofluorescence background interference of serum samples by virtue of the unique luminescence properties of PLNP and the high selectivity of MIP and aptamers,and realizes highly sensitive and selective H5N1 detection without autofluorescence,providing a new avenue for the design and practical application of sensors in complex biological samples.The main research work is as follows:1.Viral molecularly imprinted photochemical sensor based on aptamer-functionalized PLNP,named MIP-aptamer sensor was designed.To fabricate the MIP-aptamer sensor,a magnetic MIP with a selective H5N1 cavity serves as the recognition unit as well as the separation element.Meanwhile,the selected persistent luminescent nanoparticles,Zn₂Ge O₄:Mn²⁺（ZGO）,were used as luminescent signal probes due to their long-lasting luminescence properties.Then the aptamer of H5N1 was grafted onto the surface of ZGO,and aptamer-functionalized ZGO（ZGO-H5N1 Apt）was obtained.After adding H5N1,the imprinted cavity on the surface of magnetic MIP combined with H5N1 to obtain MIP-H5N1,which can selectively capture the free ZGO-H5N1Apt in solution,and quickly separate it from the sample solution,providing a sustained luminescence（PL）signal with the change of H5N1 concentration.The developed MIP-aptamer sensor has the combined advantages of not requiring in situ excitations of ZGO and high selectivity of dual recognition by aptamer and MIP,which can detect H5N1 in serum samples sensitively without autofluorescence.2.Based on the combination of persistent luminescent nanoparticles and viral molecularly imprinted polymers,a paper-based viral molecularly imprinted-aptamer sensor was prepared by using paper-based materials as the imprinting carrier for the simultaneous detection of two viruses,H5N1 virus and HBV.Paper-based materials,as a commonly material,have the advantages of low detection,easy modification and large specific surface area.They have great potential in the construction of portable sensor.Here,paper-based materials are used as imprint carriers for the first time.Two viruses were imprinted on its surface at the same time,and then two non-interfering aptamer-functionalized persistent luminescent nanoparticles were used as signal probes.Finally,under the irradiation of UV light,a unique visual signal was generated based on the combination of the two PLNP signals.