10 June 2013 Detection of melamine on fractals of unmodified gold nanoparticles by surface-enhanced Raman scattering
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Abstract
A simple way of detecting melamine in raw milk is demonstrated via surface-enhanced Raman spectroscopy (SERS) using fractals of bare and nonfunctionalized ∼30  nm gold nanoparticles (AuNP) distributed on a solid support. The technique demonstrates the formation of AuNP fractals, from a random distribution, upon exposure to melamine, that enhance the Raman scattering cross-section to enable detection by SERS. The agglomeration, which is pronounced at higher melamine concentrations, is demonstrated directly through imaging, and the red-shift of the plasmon absorption peak of the AuNP fractal away from 530 nm by finite difference time domain (FDTD) calculations. The agglomeration results in a strong plasmon field, shown by FDTD, over the interparticle sites that enhances the Raman scattering cross-section of melamine and ensures unambiguous detection. Limit of detection of 100 ppb could be achieved reproducibly.
© 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)
Pradip Kumar Roy, Yi-Fan Huang, Surojit Chattopadhyay, "Detection of melamine on fractals of unmodified gold nanoparticles by surface-enhanced Raman scattering," Journal of Biomedical Optics 19(1), 011002 (10 June 2013). https://doi.org/10.1117/1.JBO.19.1.011002 . Submission:
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