Gold coated Cicada wings for food screening by surface enhance Raman scattering
Chia Min Wang1*, Pradip Kumar Roy1, Robeth Manurung1, Surojit Chattopadhyay1,2
1Institute of Biophotonics, National Yang Ming University, Taipei, Taiwan
2Biophotonics and Molecular Imaging Research Centre, National Yang Ming University, Taipei, Taiwan
* presenting author:王嘉敏, email:turtle250178@yahoo.com.tw
A natural and low-cost surface enhance Raman scattering (SERS) substrate was prepared by vapor depositing gold on Cicada wings. Cicada wings possess low surface energies owing to the natural nanocones on its surface which makes the surface hydrophobic. The nanocones are ~400 nm in height, with a spacing of ~200 nm, and base diameter of ~200 nm. As a result, the deposited Au self-assembles to form nanoparticles on its surface. This technique is not new and has been reported before [1, 2]. However, here, for the first time we are using this facile substrate for the detection of a food toxin, namely, DEP via SERS. To maximize the SERS effect different Au coating time was used and tested with a standard 10μM R6G molecule for SERS efficiency. The best result was obtained for a 7 minute Au coated wing which will be referred to as the optimized substrate. Next, concentration dependent DEP was detected on this optimized substrate via SERS. Reasonably good linear calibration curves could be obtained for the detection and quantification purpose. We propose to use this substrate for other kinds of toxic additives in drinks such as DEHP.


Acknowledgements: National Science Council NSC-101-2112-M-010-003-MY3

References:
[1] L. Guo, et al., 2014. Journal of Applied Physics, 115, 213101.
[2] I. Tanahashi, et al., 2014. Nanoscale Research Letters, 9, 298.


Keywords: Raman Spectroscopy, Cicada wing, Food screening, Bio-sensor, Nanotechnology