Real Time Controllable Assembling/Aptasensing Of MC-LR Toxin Via Graphene Oxide-based AgClAu Hollow Triangular Nanoplate Nanocomposites

With the increase of environmental pollution and eutrophication of water bodies,aquatic ecosystems are facing the crisis of cyanobacteria outbreaks,among which microcystins are a serious threat to the health of humans,animals and plants.Therefore,in order to protect the safety of animals and humans and prevent the continuous persecution of MC on the environment,it is particularly urgent to design an accurate and simple quantitative detection and analysis system for MC-LR toxins.This paper designs a new set of nano-components for quantitative analysis and detection of MC-LR,namely: graphene oxide(GO)-based AgClAu hollow triangular nanoplate nanocomposite structure loaded Raman probe combined with aptamer hybridization technology and Streptomyces The specific combination of avidin /biotin conjugationcan perform ultra-sensitive real-time quantitative SERS detection of MC-LR.In order to prepare this composites,we constructed a high-quality hollow triangular nanoplate AgClAu: p-GO(HTNP AgClAu: p-GO)as a template.aptamer/cDNA modified with sulfhydryl groups was linked to HTNP AgClAu: p-GO,and passed The cDNA hybridization of the ligand combined with specific conjugation of biotin-streptavidin to assemble all of the components,which can tune the HNP AgClAu: p-GO component from the planar ripple to the 3D network structure,and load simultaneously the Raman probe into the component at the same time.The dynamic assembly process can be used as a real-time SERS sensor for ultra-sensitive detection of MC-LR.Because the MC-LR/aptamer competitive hybridization inhibits the hybridization of cDNA,thereby affecting the assembly of GO components,and causing the SERS signal to gradually decrease,the MC-LR can be ultra sensitively detected.Herein,the HTNP AgClAu: p-GO-aptamer sensor designed in this paper can detect MC-LR up to a detection limit of 6.3 pM,and the linear range can be from 10 pM to 5 nM.When aptasensor is applied to actual samples,the recovery rate of the real-time assembly/sampling method ranges from 97.5% to 103.3%,and the relative standard deviation(RSD)is less than 3.1%.The results demonstratethe feasibility of this strategy,and the strategy is expected to be widely used for detecting som other environmental pollutants.The new strategy of nanomaterials designed and assembled for the ultrasensitive detection of MC-LR in this thesis has the following important significance:(I)Assembling and tuning GO is beneficial to load Raman probes into the GO intermediate layer and improve the stability of SERS.(II)The ratio adjustment and combination of aptamer and MC-LR toxin helps to tune the micro-nano structure of GO assembly.(III)One-step assembly and SERS sensing simplify the detection procedure of MC-LR toxin.(IV)Using DNA-biotin/avidin technology to construct three-dimensional grapheme materials,this new nanomanufacturing method can provide high sensitivity and repeatable detection of other target analytes.