Butterfly wing scales as a model template for SERS applications

7^th Euro Biosensors and Bioelectronics Conference

July 10-11, 2017 Berlin, Germany

K Nagata, R Hirano, H Takei, T Okamoto, N Frese, H Vieker, A Beyer and A Golzhauser

Toyo University, Japan
RIKEN, Japan
Bielefeld University, Germany

Posters & Accepted Abstracts: J Biosens Bioelectron

Abstract :

We will discuss exploitation of naturally-existing nanostructures for bio-analytical techniques, specifically surface-enhanced Raman spectroscopy (SERS). Raman spectroscopy is one of the few analytical techniques capable of giving information on chemical structures without need to place the sample in a vacuum, making it well suited for on-site inspection of chemical species as in environmental monitoring, forensic sciences and quality control. There are already a number of commercial vendors selling SERS substrates, but the price needs to be reduced significantly in order to make this technique widely used. Our group has been investigating: Random-MFON structures whereby randomly adsorbed SiO2 nanospheres are coated with a noble metal and; silver dendrites grown from surface-adsorbed base metal nanoparticles in a AgNO3 solution. Here, we report on yet another method based on exploitation of scales of butterfly wings. We found that coating of butterfly wing scales, characterized by intrinsic nanostructures, with silver gives rise to a surface capable of showing SERS effects. While effectiveness depends on the butterfly species, precise scales within a single wing, the amount of deposited silver etc., there is a surprising uniformity in SERS signal intensities when these parameters are selected appropriately. By exploiting naturally-existing nanostructures, we can minimize the number of manufacturing steps, thus, reducing the overall cost. We can also obtain basic information on secret as to what makes a particular nanostructure work by selectively altering the underlying nanostrucures. This would give us an option of artificially recreating the crucial nanostructures.

Biography :

K Nagata obtained his BA in March 2017 from the Faculty of Life Sciences of Toyo University. Starting with Agriculture, his interest evolved to Entomology where he encountered the cross-disciplinary area of Biomimetics. Specifically, the possibility of using natural nanostructures found in butterfly wing scales as a basic technological platform for a new analytical technique intrigued him. As part of his graduation thesis, he carried out a detailed study on correlation between morphology of silver-coated scales and their effectiveness for surface-enhanced Raman spectroscopy. He has made his first presentation at the 76th Annual Conference of the Japan Society of Analytical Chemistry at Gifu in 2017, followed by a presentation at Pittcon 2017 in Chicago, USA. Now he is enrolled in the Master's program at the Graduate School of Life Sciences at Toyo University under the supervision of Prof. H Takei. While the main emphasis is exploitation of silver-coated scales for practical SERS applications, he is also interested in obtaining a basic understanding how different areas of the nanostructures contribute to SERS effects. Different scales are characterized by different SERS performance, and even within a single area, dorsal and ventral scales, external and internal, need to be characterized separately.

Email: s39101700135@toyo.jp