Substance specific chemical sensing with pristine and modified photonic nanoarchitectures occurring in blue butterfly wing scales.

Gábor Piszter,László Péter Biró,Zofia Vértesy,Krisztián Kertész,Zsolt Bálint

doi:10.1364/oe.22.022649

Abstract

Butterfly wing scales containing photonic nanoarchitectures act as chemically selective sensors due to their color change when mixing vapors in the atmosphere. Based on butterfly vision, we built a model for efficient characterization of the spectral changes in different atmospheres. The spectral shift is vapor specific and proportional with the vapor concentration. Results were compared to standard principal component analysis. The modification of the chemical properties of the scale surface by the deposition of 5 nm of Al(2)O(3) significantly alters the character of the optical response. This is proof of the possibility to purposefully tune the selectivity of such sensors.

Highlights

Nowadays, the potential applications of photonic crystal type materials in sensing [1] are in the focus of attention [2,3]
As sensors penetrate the everyday life, the vigorous development of sensorics tries to cover the need for miniature sensor systems which are capable of making distinction between vapors of different volatile organic compounds (VOCs) and have fast response time combined with low energy consumption [3]
We have shown recently that the conformal coverage of the butterfly wings using atomic layer deposition (ALD) with Al2O3 of a few nm thickness results in only slightly different wing reflectance signal compared to the uncoated wing [23] but it was shown earlier that the surface chemistry of the butterfly wing scale can be tuned very

Summary

Introduction

The potential applications of photonic crystal type materials in sensing [1] are in the focus of attention [2,3]. Selective chemical sensors based on photonic nanoarchitectures, like those in the wing scales of butterflies possessing structural coloration [4] may offer cheap solution to this problem. For color generation in the visible, the periodicity of optical properties (refractive index) has to be in the range of few 100 nm. This condition is well fulfilled by several photonic nanoarchitectures of biologic origin [6]. The butterfly wing scales possessing structural coloration are nanocomposites of chitin and air. This allows for their use as selective chemical sensors for volatile vapors present in the ambient atmosphere. Among the high variety of inorganic materials there are promising biological or bioinspired materials for sensors [3,10]

Methods

Results

Conclusion