Listeria Monocytogenes Detection Methods Based On CHA Amplification

The L.monocytogenes is a large concern in our environment where its ability to grow in most food products,for instance,meat,eggs and green stuff.L.monocytogenes is a well-known cause of serious immunocompromised patients,this problem has been well investigated,and many country have been taking measures.The conventional method for analysis L.monocytogenes is complex and time consuming,followed by a variety of the modern molecular biology techniques.Compared with the classical separation detection methods,the modern molecular biotechnology has a higher sensitivity,specificity and sample universality for the detection of L.monocytogenes.Catalyzed hairpin assembly is an new nucleic acid probe signal amplification technology recently,because of it has the advantages of easy to synthesis and versatility,the combination of nucleic acid probe signal amplification technology has been widely used in biological science and biological analysis and so forth.The contents of the thesis are as followed:(1)Combining the CHA and immunostrip detection L.monocytogenes.Utilize CHA as the basic reaction platform which have the signal amplification characteristics.Designing the hairpin probe and respectively label Fitc and Biotin.In the presence of target,leave a red line on the text line,change exhibited a good linear correlation with the concentration of target within the range of 200 p M to 1n M.The detection limit was calculated to be 36.4 p M.The assay was confirmed to have a good specificity and sensitivity.(2)Combining the CHA and DNAzyme detection L.monocytogenes.Utilize CHA as the basic reaction platform.The simple hairpin structure that included the G-rich in caged was designed.Upon hemin addition,it can trigger the hairpin conformation changes and from DNAzyme complexes to catalyze the H2O2 oxidation of ABTS2-to ABTS.-,which can be colors changed.The detection limit was calculated to be 60.7 p M.The assay is fairly practical and common,does not need any tags,low cost,simple design.(3)Combining the CHA and DSN-assisted dual signal amplification strategy detection L.monocytogenes.The latching of DNAzyme moieties from CHA-hybridized as signal output.The target Listeria monocytogenes can trigger the cyclical complex probes to produce CHA-trigger by DSN in the first amplification.The CHA-trigger can generate detectable fluorescence byDNAzyme.The dual amplication exhibits high sensitivity and specificity detection of L.monocytogenes.The detection concentrations as low as 434 f M.Thus,we proved that no organic dyes or labels and cost-effective strategy and holds great potential application in early clinical diagnostics.At all,combining the amplification of CHA to detect the L.monocytogenes,we achieve to detect target sensitivity and found it was easy operation,time-saving and low-cost.The test line can achieve f M,and it can be applied to single increase L.monocytogenes analysis detection in complex samples.It has great application prospective in diagnosis and so on for its many unique merits.