| Bacterial contamination greatly threats human health and public safety.The ability to more rapidly,accurately,and sensitively detect bacteria is critical to ensure the human health and public safety.Series piezoelectric sensor have been developed as potential alternatives to break the bottlenecks of the conventional methods.because they have distinct advantages,such as simple operation,low cost,and real-time online monitoring.Bacterial 16S r RNA has become a target for bacterial detection due to its unique structure.This paper focuses on the rapid detection of bacteria,and proposes a method for screening and verifying 16S r RNA sequence fragments for bacterial detection,and using this method to screen specific 16S r RNA sequence fragments for the detection of S.aureus.Based on the multichannel series piezoelectric quartz crystal(MSPQC)sensor,the 16S r RNA specific fragment of S.aureus and E.coli was used as the detection target,the highly sensitive S.aureus and E.coli piezoelectric biosensor were constructed.This dissertation includes the following three parts:(1)Screening and verification of species-specific 16S r RNA fragments for the identification of S.aureusS.aureus is a widely distributed pathogen that causes many infectious diseases.Thus,the identification and quantitation of S.aureus have become a crucial point in medical diagnosis,food safety,environmental hygiene,and drug discovery.However,the lack of ideal targets with high abundance,good intra-species universality,good inter-species specificity,and easy measurement has affected the accuracy of S.aureus detection methods.In order to obtain the ideal target,this article uses 16S r RNA with high abundance in the bacteria as the research object,Using the intra-species universality,extra-species specificity,extra-bacteria specificity,and hybridization efficiency as evaluation indicators,the 16S r RNA sequence fragment targets that can identify S.aureus species were selected and verified by PCR and electrophoresis technology.In summary,the target for S.aureus identification can be obtained by using the constructed method,and this method has broad application prospects in the design of bacterial species identification targets.(2)Construction of a novel multi-channel series piezoelectric quartz crystal S.aureus sensor based on 16S r RNAS.aureus is a widely distributed Gram-positive pathogen that causes many dangerous infectious diseases.Thus,the identification and quantitation of S.aureus have become a crucial point in medical diagnosis,food safety,environmental hygiene,and drug discovery.Here,we show that,using 16S r RNA specific fragment of S.aureus as the detection target and MSPQC sensor as signal receptor,through the formation of hybridization chain reaction(HCR)product-templated silver wires which is stretched across the gap between inner finger of interdigital electrode,a highly sensitive,label-free,enzyme-free,isothermal biosensor is presented to detect S.aureus in two step at room temperature.The biosensor designed under the optimal conditions has a good linear relationship in the range of S.aureus concentration from 10~2to 10~7CFU/m L in lysozyme-processed samples,the detection limit is 15CFU/m L,the detection time is 90 minutes.E.coli,S.enteritidis,P.aeruginosa did not interfere with the detection results.In summary,a simple,specific,rapid and super-sensitive platform for the early detection of bacterium was developed and might become a promising tool applied in fields of food/public safety monitoring and clinical diagnosis.(3)Construction of a novel multi-channel series piezoelectric quartz crystal E.coli sensor based on 16S r RNAE.coli,one of the most common clinical pathogens,cause a series of life-threatening diseases and enormous medical and financial burden.To combat E.coli infectious diseases and effectively decrease their damage,rapid E.coli differentiation,detection and bactericide screening are the foremost crucial steps.Here,we show that,using 16S r RNA specific fragment of E.coli as the detection target and MSPQC sensor as signal receptor,through the formation of rolling circle amplification(RCA)product-templated silver wires which is stretched across the gap between inner finger of interdigital electrode,a highly sensitive,rapid,and specific biosensor is presented to detect E.coli.The biosensor designed under the optimal conditions has a good linear relationship in the range of E.coli concentration from 10~2to 10~7CFU/m L in lysozyme-processed samples,the detection limit is 12 CFU/m L,the detection time is 120 minutes.S.aureus,S.enteritidis,P.aeruginosa did not interfere with the detection results.In summary,a simple,specific,rapid and sensitive platform for the early detection of bacterium was developed and might become a promising tool applied in fields of food/public safety monitoring and clinical diagnosis. |
PDF Full Text Request