Studies On Live Detection Technique For Marine Pathogen

A review on marine bacteria,gold label silver stain?GLSS?,and anodic stripping voltammetry was systematically carried out.GO and g-C3N4 are the two-dimension nanomaterials and have some excellent properties.Excellent biocompatibility and high surface area make then applicable to biomedical and analysis fields.This paper is combination nanomaterials with GLSS and anodic stripping voltammetry,developing a series of simple and low-cost sensor.This will set a solid foundation for further step development of marine pathogen live detection.The detail contents were described as follows:1.Christmas-tree derived amplification immuno-strategy for sensitive visual detection of Vibrio parahaemolyticus based on gold label silver stain technologyA developed Christmas-tree derived immunosensor based on a gold label silver stain?GLSS?technique was fabricated for a highly sensitive analysis of Vibrio parahaemolyticus?VP?.In this strategy,captured VP antibody?cAb?was immobilized on a solid substrate;then,the VPs were sequentially tagged with a signal probe by incubating the assay with a detection VP antibody?dAb?conjugated gold nanoparticles?AuNPs?-labeled graphite-like carbon nitride?g-C3N4?.Finally,the attached signal probe could harvest a visible signal by the silver meal deposition,and then followed by homebrew Matlab 6.0 as a grey value acquisition.In addition,the overall design of the biosensor was established in abundant AuNPs and g-C3N4 with a two-dimensional structure,affording a bulb-decorated Christmas-tree model.Moreover,with the optimized conditions,the detection limit of the as-proposed biosensor is as low as 10² CFU?Colony-FormingUnits?mL^-1,exhibiting an increase of two orders of magnitude compared with the traditional immune-gold method.Additionally,the developed visible immunosensor was also successfully applied to the analysis of complicated samples.2.Electrochemical immunosensor for detection of Vibrio parahaemolyticus based on Faradaycage-type anodic stripping voltammetryThis paper aims to develop a Faradaycage-type immunoassay mode combining with anodic stripping voltammetry for Vibrio parahaemolyticus?VP?detection.GO-supported AgNPs?AgNPs@GO?were synthesized and used to label detection antibody?dAb?as the detector unit.The immunoassay was performed on a magnetic glassy carbon electrode via immunoreactions among the AgNPs@GO-labeled dAb,VP,and capture antibody?cAb?.The detection sensitivity is expected to be considerably enhanced owing to two reasons:?1?large amounts of adsorbed AgNPs on the GO surface,made the electrochemical responses more sensitive;?2?thanks to the combined immune structure of Faradaycage-type,all AgNPs labeled on the detector unit could take part in the electrode reaction to emit signals.Under optimal conditions,the immunosensor exhibits a relatively wide linear range from 10² to 10⁸ CFU mL^-1 with a detection limit of 33 CFU mL^-1.In addition,high selectivity and excellent recovery in seawater and seafood indicate that this immunosensor shows great prospect for practical application.Featured with high sensitivity,the proposed sensing scheme can thus offer new opportunities to achieve sensitive,selective,and simple detection of other bacteria.3.A dual channel immunosensor for ultrasensitive detection of Vibrio vulnificus based on FSSV and ECLThis study aims to develop a dual channel immunosensor for detection of Vibrio vulnificus based on FSSV?Fast scan stripping voltammetry?and ECL?Electrochemiluminescence?.G-C₃N₄supported AgNPs?AgNPs@g-C3N4?were synthesized and used to label detection antibody?dAb?as the detector unit.Interesting,AgNPs@g-C₃N₄ cannot only act as signal for FSSV but also emit ECL.Compared with g-C3N4,the prepared AgNPs@g-C3N4 nanohybrids exhibit strong and stable ECL activity.The reason is the important roles of AgNPs in trapping and storing the electrons from the conduction band of g-C₃N₄,as well as preventing high energy electron induced passivation of g-C3N4.Compared with the common ASV,the signal was amplified by implementing the high scan rate of FSSV.Under optimal conditions,the immunosensor showed wide liner range from 10-10⁵ CFU mL^-1 with a detection limit of 3 CFU mL^-1.Simultaneously,this immunosensor has acceptable stability,reproducibility and accuracy.