Bio-magnetic nanoparticles based electrochemical biosensor or immunosensor

• Main Author: Ng, Ying Kiat.
• Other Authors: Raju Vijayaraghavan Ramanujan
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/15397
• Institution: Nanyang Technological University

Iron oxide has been long recognized as an important source of chemical compounds for industrial and electronic applications due to the vast range of magnetic properties exhibited by the huge variety of oxides present. Recently, there has been a growing interest in the field of biomedical research to adopt such magnetic particles in nano-size range due to the promising characteristics such as low toxicity, good thermal stability and biocompatibility that they offer. Among the many methods to synthesize iron oxide nanoparticles, microwave synthesis was chosen as it has many advantages such as reduced processing time and lower cost. Iron (III)nitrate and sodium hydroxide were used as precursors to synthesize the iron oxide nanoparticles. Varying levels of irradiation power and pH of precursors were selected to investigate the morphology and magnetic properties of the products formed. These properties were investigated using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Vibrating Sample Magnetometer (VSM) technique. Using microwave-assisted synthesis, the sample with smallest particle size (54.5nm) retained the highest magnetization of 0.950 emu/g after heat treatment for 4 hours at 400°C. However, the sample with smallest particle size (54.1nm) did not have the highest saturation magnetization when microwave-combustion method was used. Hematite was the most abundant phase present in most of the samples; heat treatment time was increased to increase the extent of phase transformation as it was not the optimum phase for biomedical application. However, further investigation can be employed to establish its use for other biosensor applications that is not based on antigens.