The Preparation of Silicon and Silver-Based Nanomaterials for Biological Applications
Creators: Mertoglu, Cemre
Publisher: name: University of Alberta Library
Year: 2024

<p>Mesoporous silica nanoparticles (MSNPs) are used in catalysis, drug delivery, controlled drug release, imaging and biosensing applications due to their stability, high pore volumes, large surface area and non-toxicity. Although MSNPs have many advantages in biological applications, they lack optical properties. This limits the functionality of these materials in terms of in-situ response. Therefore, combining mesoporous silica with nanoparticles results in hybrid materials that provide unique systems for biosensing. One drawback of using these hybrid materials in sensing applications is the non-selective nature of the system as the pores of mesoporous silica do not discriminate between the molecules of interest and other molecules in the sensing medium. For this reason, molecular imprinting is essential to produce hybrid materials with the needed selectivity. This thesis focuses on work related to combining the nanoparticles with surface imprinted mesoporous silica. Possible applications of these hybrid materials are then studied.<br>
Chapter 1 introduces the concepts of nanoparticles, mesoporous silica, and molecular imprinting. Synthesis routes, properties and applications of these materials are discussed. <br>
In Chapter 2, we aim to prepare silicon nanoparticles (SiNPs) embedded in surface imprinted mesoporous silica. SiNPs were prepared by high temperature processing of hydrogen silsesquioxane (HSQ) and the surface of the SiNPs were passivated with dodecyl groups. Encapsulation of SiNPs in mesoporous silica (MSNPs-SiNPs) was performed via a sol-gel reaction. Surface modification of MSNPs-SiNPs was achieved by introducing vinyl groups followed by radical initiated polymerization. The polymer (ethylene glycol dimethacrylate) was molecularly imprinted using ibuprofen (IBU) as a template molecule. Throughout this investigation we assessed the surface chemistry of the MSNPs-SiNPs by Fourier-transform infrared (FTIR). The successful preparation of the imprinted polymer on the surface of the particles was assessed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). With this hybrid material in hand, we turned our attention toward determining the template loading/release efficiency of the material. <br>
Chapter 3 describes the preparation of AgNPs embedded in surface imprinted mesoporous silica. The AgNPs were prepared using a chemical reduction method and subsequent encapsulation of AgNPs in mesoporous silica was performed via a sol-gel reaction. The surface modification of the AgNPs embedded mesoporous silica was again achieved by the introduction of vinyl groups followed by radical initiated polymerization on the surface of the MSNPs-AgNPs. The polymer (poly(N-isopropyl acrylamide)-co-poly(acrylamide)) was molecularly imprinted using urea as a template molecule. Following the methodology in Chapter 2, the surface chemistry of the MSNPs-AgNPs was investigated using Fourier-transform infrared (FTIR), Thermogravimetric analysis (TGA), and Dynamic light scattering (DLS). The successful preparation of the imprinted polymer on the surface of the particles was evaluated by TGA and Scanning electron microscopy (SEM).  Next, we turned our attention toward determining the template loading/release efficiency of this hybrid material. <br>
Finally, Chapter 4 summarizes the outcome of the experimental results and describes relevant future directions.</p>