Advanced Structural Engineering of Nanoporous Photonic Structures: Tailoring Nanopore Architecture to Enhance Sensing Properties

Abstract

In this study, we demonstrate that an optimal design of the pore geometry and shape of sensing platforms based on nanoporous anodic alumina (NAA) photonic structures is critical to develop optical sensors with improved capabilities. To this end, two types of NAA photonic structures featuring different pore geometries (i.e., pore lengths and diameters) and shapes (i.e., straight and modulated pores) were produced, and their optical characteristics were assessed systematically by reflectometric interference spectroscopy. The geometric features (i.e., pore lengths, diameters, and shapes) were systematically modified in order to establish the optimization paths for the sensitivity, low limit of detection, and linearity of these optical sensing platforms. The obtained results reveal that an optimal design of these nanoporous photonic structures can enhance their sensitivity, achieve a lower limit of detection, and improve their linearity for both nonspecific and specific detection of analytes. Therefore, as this study demonstrates, the rational design of optical nanoporous sensing platforms is critical in the development of reliable, sensitive, robust, inexpensive, and portable optical systems for a broad range of sensing applications.

Rational engineering of nanoporous anodic alumina optical bandpass filters

“…[22][23][24][25][26][27][28] Recently, some of these approaches have been used to produce numerous NAA-based photonic structures, including rugate filters, optical microcavities, FabryPerót interferometers and distributed Bragg reflectors. [29][30][31][32][33][34][35][36][37][38][39] The development of optical platforms based on NAA has spread the use of this nanomaterial, typically used as a nanoporous template to grow other nanostructures such as nanowires and nanotubes 15 , towards more relevant applications such as optical sensing systems, drug delivery chips and photonic tags. [40][41][42][43][44][45][46][47][48][49][50][51] In this study, we present an innovative and rationally designed pulse anodisation approach, so called pseudo-stepwise pulse anodisation (PSPA), which enables the fabrication of nanoporous anodic alumina optical bandpass filters (NAABPFs) with advanced optical properties (Fig.…”

On The Generation of Interferometric Colors in High Purity and Technical Grade Aluminum: An Alternative Green Process for Metal Finishing Industry

“…Rationally designed electrochemical approaches have recently shown that biomimetic photonic films based on nanoporous anodic alumina (NAA) generated on the surface of aluminum by anodization could overcome the limitations of current metal coloring processes through eco-friendly fabrication approaches. [17][18][19][20] NAA photonic films can reflect light at specific wavelengths within the UV-visible-NIR spectrum by interferometric phenomenon, which in turn results in aluminum pieces displaying vivid and bright colors. [21][22][23][24][25][26][27][28] The color of these anodic films can be tuned across the UV-visible-NIR spectrum by engineering their photonic stop band through the internal nanoporous structure, without the use of toxic chemical compounds or additional fabrication stages.…”

Optical Properties of Nanoporous Anodic Alumina and Derived Applications

“…The same approach has been also demonstrated to the detection of Hg 2+ ions in water wit a limit of detection of 1 μM. Finally, a comparison between the two RIfS methods presented in this section can be found in [129] and more detailed reviews on these applications in [130,131].…”