Sensitive Detection And Antibacterial Effect Of Fucose-functionalized Nanomaterials Against Pseudomonas Aeruginosa

Pseudomonas aeruginosa(P.aeruginosa)is a kind of conditional pathogenic bacteria widely existing in water,air and soil,which is common in drinking water pollution,processing equipment pollution in food factories and medical equipment pollution in hospitals,etc.Moreover,the sterilization effect of common disinfection methods on the bacteria is not good.Therefore,the development of a sensitive and specific method for the detection of P.aeruginosa and the synthesis and development of new antibacterial materials can effectively prevent and control the pollution of P.aeruginosa.In this paper,based on the specific recognition of fucose and P.aeruginosa,two kinds of Fuc functionalized nanomaterials were designed and synthesized based on the recognition mechanism,which realized the specific sensitive detection and sterilization of P.aeruginosa respectively.The main research contents and results can be summarized as follows:1.Study on rapid and sensitive detection method of Pseudomonas aeruginosa based on fucose functionalized carbon dotsBased on the excellent fluorescence characteristics of carbon dots(CDs)and the specific recognition of fucose(Fuc)on P.aeruginosa,a fluorescent probe which can detect P.aeruginosa specifically and sensitively was designed.Using citric acid and ethylenediamine as carbon and nitrogen sources,CDs with more amino groups on the surface was synthesized by hydrothermal method(about 3 nm in size).The Fuc functionalized carbon dots(F-CDs)were synthesized by nucleophilic addition reaction between aldehyde groups on Fuc and amino groups on the surface of CDs.The volume ratio of bacterial suspension to F-CDs,the different ratio of synthetic F-CDs(Fuc:CDs)and the incubation time of F-CDs with target bacteria were investigated,and the optimal detection conditions of F-CDs for P.aeruginosa were obtained.The linear range of this method is 10-8.5×109 CFU/ml,and the lowest detection limit is 3 CFU/mL through calculation.In addition,compared with the results of plate counting method,this method has good applicability for the detection of P.aeruginosa in actual samples such as milk,fruit juice and tap water.The method is simple to operate,low in cost and good in selectivity,and has great potential in the specific and sensitive detection of P.aeruginosa.2.Study on antibacterial effect of fucose functionalized polyethyleneimine copolymer particles on Pseudomonas aeruginosaPolyethyleneimine(PEI)has been widely studied in the fields of drug carriers,gene transfection and antimicrobial agents because of its broad-spectrum antibacterial and easy modification.However,PEI's damage to normal host cells limits its development as an antibacterial drug.Therefore,how to improve the antibacterial performance of PEI with low toxicity is a hot research topic at present.Three hydroxyl groups in Fuc can coordinate with two calcium ions on PA-IIL lectin of P.aeruginosa to realize its specific recognition.Fuc-PEI CPs was synthesized by the addition reaction between amino group on PEI and aldehyde group on Fuc.The Fuc-PEI CPs not only retains the specific recognition of Fuc to P.aeruginosa,but also has the antibacterial activity of PEI.The antibacterial activity of Fuc-PEI CPs was evaluated by plate counting method.Compared with unmodified PEI,Fuc-PEI CPs had better antibacterial activity against P.aeruginosa,and its minimum bactericidal concentration was 2.5?g/mL.In addition,cytotoxicity test and hemolytic test prove that Fuc-PEI CPs has the characteristics of low cytotoxicity and good biocompatibility.As a new type of antimicrobial agent,Fuc-PEI CPs provides an idea for the development of a new type of highly effective antimicrobial agent against P.aeruginosa.