Optical Properties of Nanoporous Anodic Alumina and Derived Applications

Abstract

Inexpensive formation of periodically ordered structures with periodicities and feature sizes lower than 100 nm has triggered a vast amount or research in recent years. Of particular interest in nanotechnology is the nanoporous alumina, which can be produced with a self-organized arrangement of pores in the adequate anodization conditions. Most of the interest of this material is based in its outstanding physical and chemical and properties, and more specifically in its optical properties. The interaction of light with the nanostructured porous alumina gives rise to a wealth of optical properties that have their interest both in research level and also in application. In this work we aim at giving an extensive review of the published research on the optical properties of nanoporous alumina. The review will account for the different studied optical properties of this material such as the existence of a photonic stop band originated from its quasi-random nanostructure, the interferometric and light guiding properties that can be applied to biosensing, the structure nanoengineering to achieve more complex photonic behaviour such as distributed-Bragg reflectors or rugate filters, and the photoluminescence properties. In a second part, a summary of the different applications proposed on the basis of these properties, such as in biotechnology or energy will be given. IntroductionAmong the different features and properties of porous anodic alumina (p-AAO), its optical properties are of special interest and have been the subject of very intensive research. The interaction of light with p-AAO can be analyzed from different points of view: the material interaction, the porous structure interaction or the relation of geometrical features of the nanostructure (periodicity or quasi-periodicity, distance

Advances in Optical Biosensors and Sensors Using Nanoporous Anodic Alumina

“…Various applications have been reported for NAA such as biosensors [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ], sensors [ 36 , 66 , 67 , 68 , 69 , 70 , 71 ], drug release [ 72 , 73 , 74 , 75 , 76 ], template-based nanowire, and nanotube fabrication [ 77 , 78 , 79 , 80 ]. Among the various sensors and biosensors that have been reported based on NAA, optical biosensors are the more interesting because of their remote sensing ability and properties such as being small and lightweight, having high sensitivity, and being immune to electromagnetic interference [ 81 , 82 , 83 , 84 , 85 , 86 ].…”

Real-Time Monitoring of Biotinylated Molecules Detection Dynamics in Nanoporous Anodic Alumina for Bio-Sensing

“…The surface chemistry of NAA permits the introduction of useful functional groups (e.g., carboxyl, amin) by means of self-assembly silanization with aminopropyl-triethoxy silane (APTES) [24], mercaptopropyl-triethoxy silane [25], 3-isocyanatopropyl triethoxy silane (ICN) [26], polyethylene glycol-silane (PEG-silane) [27], and several other silanes. Moreover, NAA possesses unique optical properties, such as characteristic reflectance spectra governed by Fabry–Perot interferences, that exploit NAA as a platform to study the chemical interactions in biosensors using RIfS [28,29].…”

Optical reflectance from anodized Al-0.5 wt % Cu thin films: Porosity and refractive index calculations

“…Examples of devices for applications are chemical sensors, biosensors, optical waveguide sensors, distributed-Bragg reflectors or rugate filters, etc. [1][2][3]. The porous anodic alumina (PAA) is formed when aluminum (Al) samples are electrochemically anodized in an acidic medium under specified anodization conditions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…There is an increasing attention towards optical characterization of different kinds of PAA [1][2][3][4]. The optical reflectance of the thin film is dependent on its refractive index, porosity, and the film thickness.…”