University of Waterloo, Canada
Y Bustami is a Lecturer at the School of Biological Sciences, University of Science, Malaysia. She did her first degree at the National University of Malaysia in Genetics (Bioscience and Biotechnology). Then, she obtained an MSc from the University of Science, Malaysia in Biotechnology. She has completed her PhD last year (2016) in the Department of Chemical Engineering, University of Waterloo, Canada. Her PhD work is on the development of nanocatalytic-based assay for the detection of an endocrine disrupting compound in aqueous solution. Her current research interest includes nanoparticles synthesis and characterization, immobilization of biomolecules on nanoparticles and development of nanosensor technology.
Magnetic iron oxide-gold nanoparticles (IONPs-AuNPs) could provide a useful platform for biosensing purposes. The aim of this study was to investigate the formation of such particles using a simple electro- static self-assembly technique, and then to demonstrate their application using a glucose detection assay. AuNPs were attached to the IONPs surface by ionic interaction, as verified using UV–Vis spectrophotometry. Then, a carbodiimide-coupling technique was used to covalently attach glucose oxidase (GOx) onto the nanoparticles’ surface and the bioactivity was measured using an ABTS colorimetric assay. For characterization, UV–Vis spectrophotometer, DLS, zeta potential, TEM, EDX, XPS and FTIR techniques were used. The particle diameter obtained from TEM was 16.1±11.1 nm and EDX confirmed the presence of Au and Fe elements. In addition, FTIR results exhibited strong vibrational modes around 1654, 1546 and 3369 cm-1 that appeared to be primarily due to immobilization of GOx onto Fe/Au. The colorimetric assay also showed a significant increase in green color intensity, due to oxidation of ABTS, with increasing glucose concentrations ranging from 20 M to 100 M. IONPs/Au nanoparticles showed a good potential for application in this colorimetric assay, thus suggesting an excellent basis for a nanosensor system using these particles.