Fabrication of large-area ordered and reproducible nanostructures for SERS biosensor application

Abstract

We propose a large-area SERS device with efficient fluorescence quenching capability. The substrate is based on anodic porous alumina templates with various pore size and wall thickness as small as 15 and 36 nm, respectively. The nano-patterned SERS substrate, with excellent control and reproducibility of plasmon-polaritons generation, shows very efficient enhanced Raman signal in the presence of intrinsically fluorescent molecules such as cresyl violet, rhodamine, and green fluorescent protein. This work demonstrates that, when the nanostructures are properly designed and fabricated, Raman and fluorescence spectroscopy can be used in combination in order to obtain complementary molecular informations. Theoretical simulation shows excellent agreement with the experimental findings. The enhancement factor is found to be 10(3)-10(4), with respect to flat gold surface when the molecules are supposed to be closely packed, with considerable fluorescence suppression, showing a promising disposable biosensor.

Thin nanoporous alumina-based SERS platform for single cell sensing

“…The capability of tuning the ratio wall thickness/pore size (w/d) is of strategic importance for SERS applications [49,50]. Post-production etching allowed to obtain APA surfaces with increasing pore size and constant pitch.…”

“…In this respect, assessing the influence of the A c c e p t e d M a n u s c r i p t surface porosity of APA on cell adhesion would provide valuable information. In addition, metal coated thick APA can be used as an efficient large-area SERS substrate [49][50][51]. In a few cases APA was already used for SERS applications, but mainly as a mold to fabricate plasmonic nanostructures, for example gold (Au) NPs arrays.…”

Preparation and analysis of anodic aluminum oxide films with continuously tunable interpore distances

“…These nanoarrays have potential applications in many fields such as renewable energy, magnetic data storage media, photonic devices, protein separation, surface enhanced Raman spectroscopy, sensors and biomedical applications [1][2][3][4][5][6][7][8][9][10][11][12][13]. The AAO films possess self-organized hexagonal arrays of uniformly sized and parallel nanochannels.…”

Mesoporous alumina as a biomaterial for biomedical applications

“…For instance, in ref. [94], a study on the fabrication of disposable SERS biosensors based on PAA and the thermal evaporation of gold within the pores is presented. In this study, an enhancement factor of up to 103 to 104 in Raman spectroscopy with respect to a flat gold surface is reported, using intrinsically fluorescent molecules such as cresyl violet, rhodamine of green fluorescent protein.…”