A Study On The Electrochemical Techniques For Detection Of Sulfate-reducing Bacteria

This thesis focuses on the discussion for assembly, fabrication and optimizationof biosensor, the novel application of environmental monitoring for sulfate-reducingbacteria (SRB) detection. In the present dissertation, we fabricated several new sensorplatform for the immobilization of biochemical molecules. A series of new analysistechniques with and without nanoparticle labels were also developed for studying theresponse amplification, which provides as a novel pathway for bacteria detection. Themain content of the thesis are as follows:1. An original method for biocorrosion mechansim was reported. Wesystemically studied the dissolved oxygen for effect on biocorrosion mechanism.Oxygen dissolved in the culture solutions induced slow growth and fast decay of SRBand inhibited the biocorrosion. The biofilms that formed under aerobic conditionsexhibit a homogeneous and loose structure because the proliferation and metabolicactivities of SRB under aerobic conditions were inhibited, resulting in the change inthe thickness and density of biofilm.2. A new approach for the fabrication of sensor platform was reported. Fourkinds of sensor platforms based on self-assembled monolayer, bioinspired film,electropolymerization technique and three dimensional foam Ni were designed forstudying the correlation between impedimetric immunosensor response and microbialpopulations. The well correlation between sensor response and microbial populationswas established.3. A novel technique for bacteria detection with nanoparticle labels was alsoreported. We discovered the peroxidase-like property of Manganese oxide nanowireand the self catalytic property of graphene oxide nanosheets, which were used forsignal amplification in biosensor. We also studied the response enhancement ofmagnetic nanoparticles in quartz crystal microbalance and lead sulfide inpotentiometric stripping voltammetry for monitoring microbial population, whichdemonstrated that the present method can be used for high sensitivity detection ofSRB.