Bottom-Up Synthesis of Mesoporous TiO2 Films for the Development of Optical Sensing Layers

Abstract

Many optical sensors exploit the interesting properties of porous materials, as they ensure a stronger interaction between the light and the analyte directly within the optical structure. Most porous optical sensors are mainly based on porous silicon and anodized aluminum oxide, showing high sensitivities. However, the top-down strategies usually employed to produce those materials might offer a limited control over the properties of the porous layer, which could affect the homogeneity, reducing the sensor reproducibility. In this work, we present the bottom-up synthesis of mesoporous TiO2 Fabry-Pérot optical sensors displaying high sensitivity, high homogeneity, and low production cost, making this platform a very promising candidate for the development of high-performance optical sensors.

Evaluation of Mesoporous TiO2 Layers as Glucose Optical Sensors

“…A stable homogeneous sol was prepared by following the method previously reported, with some modifications [ 27 ]. The sol synthesis was conducted by the initial hydrolyzation of TTIP in the acidic mixture of 1-butanol, hydrochloric acid and water, counting also with the P123 (EO 20 PO 70 EO 20 ) block copolymer.…”

“…Within this context, we have developed a bottom-up synthesis process for the creation of TiO 2 mesoporous layers with a high degree of interconnectivity and homogeneity for the development of optical sensors based on Fabry–Pérot interferometry [ 27 ]. Selecting TiO 2 as the inorganic material of the porous framework ensures a high refractive index for the porous scaffold ( n TiO2 ≈ 2.56), hence enabling the porous layer to count on a sufficiently high effective index to provide an adequate optical response.…”

On-Wafer Wide-Pore Anodic Aluminum Oxide

“…[5][6][7][8][9][10][11][12][13] Initially led by Matsuda et al, AAO has attracted significant attention as a template for the fabrication of various nanostructured materials and devices. 14 These include, but are not limited to; sensors, [15][16][17][18][19] filters, [20][21][22][23] optics, [24][25][26][27][28][29] piezoelectrics, [30][31][32][33][34] catalysis, [35][36][37][38][39][40] and energy storage devices, [41][42][43][44][45][46] where it has played multiple roles. As a template it has been used for synthesizing nanoscale electrodes for both cathode and anode materials including but not limited to Li, Na, Mg, and Al systems, or as separators to achieve high performance devices.…”