| dc.description.abstract | Milk is one of the essential food items throughout the world. Intentional
adulteration of milk products with melamine falsely increases the apparent protein
content in milk and it is a health concern associated with kidney damage. Therefore,
developing an effective method for detecting melamine is important. In this
research, a highly sensitive SERS (Surface Enhance Raman Spectroscopy) technique
was applied to detect lower concentrations of melamine with silver nanoparticles to
indicate the potential of Raman spectroscopy to design an optical biosensor. This
preliminary investigation can address shortcomings of high-cost and sophisticated
detection techniques and enables the applicability in onsite detection of melamine.
In the experiment, the nanoparticles and samples were mounted on tsetupan set up
using the hanging drop method and drop casting method. The Raman
measurements were obtained using a custom-built research-grade Raman
spectrophotometer with a laser wavelength of 532 nm. The most sensitive SERS
probe was developed when classical silver nanoparticles were drop cast on the glass
slide. Therefore, further quantitative analysis including method validation and
application into commercial milk samples was performed using the drop-casted
sample. The calibration plot for the intensity of the SERS peak at ~691 cm-1 versus
melamine concentration shows linearity in the range of 0.2 ppm- 50 ppm for the
SERS probe developed via drop casting classical silver nanoparticles. The limit of
detection and limit of quantification for this method are 3.05 ppm and 10.16 ppm,
respectively. This developed SERS probe allows quick, simple, and cost-effective
qualitative and quantitative analysis of melamine. | en_US |
