The Application And Research Of The Biosorption Of Lysozyme Using SPR Technology

Surface plasmon resonance (SPR) sensor is a potential technology in science, which provides some advantages such as label-free, high sensitivity, quantitative sensing and real-time analysis and so on. It is a novel and sensitive biochemical measurement technology. SPR technology has been widely applied in environmental monitor, biomedicine and medicament selection etc. In this dissertation, the continuity of nanoparticle thin film prepared in lab is studied by SPR, biosorption of lysozyme and its application on E. coli detection are investigated. The followings are the details of these experiments.First, study of the assembly of gold nanoparticles film and its continuity. The research of two-dimension microstructures based on the sensitive optoelectronic properties of noble metal nanoparticles becomes a fast developing field. In this dissertation, gold nanoparticles with a diameter of11nm are prepared by reduction method, then, the gold nanoparticles are coated with alkanethiol surfactant. Ethanol is chosen as agent to decrease the interfacial energy, and direct close-packing of11nm-sized gold nanoparticles at a Water|Hexane interface. The optimal condition is obtained. Then the film could be transferred to a solid substrate by horizontal lifting. The surface of gold nanoparticle thin film annealed at the temperature of400℃is rather smooth. With these procedures, fine gold nanoparticle film is prepared.Second, study of the biosorption of lysozyme. The lysozyme is non-toxic, harmless and environmentally friendly protein, which can hydrolyze the cell wall of microorganisms. In this dissertation, the adsorption of lysozyme is studied on1-dodecanethiol self-assembled monolayer (SAM) surface. A home-built SPR apparatus based on the Kretschmann configuration was used for this biosorption, and the adsorption curve fits well with the Langmuir adsorption isotherm. After the gold particles are introduced, LSPR enhancement effect enhances the adsorption signals. A very high sensitivity is achieved.Last, the detection of E. coli. A new method for E. coli detection is suggested. Based on the significant inhibitory effect of lysozyme on E. coli, E. coli is detected using lysozyme adsorbed on the chip of SPR bio-sensors for the first time, and the lowest limit of detection is10cfu/mL.