Planar Monolithic Porous Polymer Layers Functionalized With Aunps As Sers Substrates And Its Application In Bioanalysis

Surface enhanced Raman spectroscopy (SERS) not only has the advantages of no damage, rapid and high sensitivity but also can provide molecular structure information. It is conducive for the detection of bacteria and other biological samples in clinical samples.The construction of SERS substrate is the key to enhance SERS signal. In this thesis, we synthetize planar monolithic porous polymer layers functionalized with gold nanoparticles and serve it as a new SERS substrate. And when it is used for SERS detection of microorganisms, it can avoid the disadvantages of complex, time-consuming and low detection sensitivity. And it is importantly significant in the detection of bacterial infectious diseases.The research content of this thesis can divide into the following four parts:1. Synthetizing gold nanopaticles and poly(glycidyl methacrylate-ethylene dimethacrylate) planar porous and nonporous monolithic layer, the monolithic layer is functionally modified with thiol group and then functionalized with gold nanoparticles. Transmission electron microscopy is used to characterize the nanoparticles. Scanning electron microscopy with X-ray diffraction spectroscopy and atomic force microscopy are used to characterize the morphology and surface roughness of the monolithic layers;2. Studying the SERS properties of the planar monolithic porous polymer layers functionalized with gold nanoparticles and detecting E.coli: analyzing effect of size of gold nanoparticle on the performance of SERS; detecting the SERS signal of different concentration of nile blue A to test the minimum detection limit; calculating the enhancement factor and studying the enhancement mechanism using Finite Difference Time Domine (FDTD); analyzing the repeatability and reproducibility of the planar monolithic porous polymer layers functionalized with gold nanoparticles; and compare the SERS property on the monolithic porous polymer layers functionalized with gold nanoparticles with the nonporous one; functionalizing the SERS substrate with thiol-containing modifiers and absorbing E.coli for SERS detection;3. Preparing pH-responsive monolithic porous polymer layers via "thiol-ene" click reaction using a mixture of hydrophobic lauryl methacrylate (LMA) and pH sensitive 10-undecylenic acid and mixture of LMA and [2-(methacryloyloxy)ethyl] dimethyl-(3-sulfopropyl)ammonium hydroxide (SPE), then scanning electron microscopy and atomic force microscopy are used for characterization;4. Study on the influence of surface wettability on SERS performan ce. Immerseing the pH-responsive monolithic porous polymer layer functionalized with the mixture of hydrophobic LMA and 10-undecylenic acid into different pH solution to obtain the superhydrophobic and superhydrophilic surface, respectively. Then bonding 4-mercaptobenzoic acid dyes to gold nanoparticles to obtain the Au-MPBA nanoparticles and detecting its SERS signal on superhydrophobic and superhydrophilic monolithic porous layers,respectively. Then comparing the SERS signal of Au-MPBA nanoparticles on superhydrophobic surface with the one on superhydrophilic surface to study the effect of surface wettability on SERS performance. Then in situ synthetizing gold nanoparticles on the surface of E.coli and detecting the SERS signal of E.coli on the superhydrophobic and superhydrophilic porous monolithic layers, respectively.