Ali, Babar (2024) Self-Assembled Nanostructured Substrates for ATR-SEIRA Applications. [Tesi di dottorato]

[thumbnail of Ali_Babar_36.pdf]
Preview
Text
Ali_Babar_36.pdf

Download (25MB) | Preview
Item Type: Tesi di dottorato
Resource language: English
Title: Self-Assembled Nanostructured Substrates for ATR-SEIRA Applications
Creators:
Creators
Email
Ali, Babar
engrbabarali00786@gmail.com
Date: 31 January 2024
Number of Pages: 166
Institution: Università degli Studi di Napoli Federico II
Department: Ingegneria Elettrica e delle Tecnologie dell'Informazione
Dottorato: Information technology and electrical engineering
Ciclo di dottorato: 36
Coordinatore del Corso di dottorato:
nome
email
RUSSO, STEFANO
stefano.russo@unina.it
Tutor:
nome
email
Antonello, Cutolo
UNSPECIFIED
Date: 31 January 2024
Number of Pages: 166
Keywords: IR, ATR-SEIRA, ATR-FTIR, self-assembled substrates, SEM, biological sensing
Settori scientifico-disciplinari del MIUR: Area 09 - Ingegneria industriale e dell'informazione > ING-INF/01 - Elettronica
Date Deposited: 15 Mar 2024 15:28
Last Modified: 12 Aug 2026 05:36
URI: https://www.fedoa.unina.it/id/eprint/15583

Collection description

Infrared (IR) spectroscopy is a versatile tool for point-of-care systems such as biological sensors. Due to small the intrinsic cross-section of a molecular vibration which limits the sensitivity of detection, but it can be addressed in several ways, including improving the IR light source, forming extremely sensitive IR detection devices, by taking advantage of the SEIRA (Surface Enhanced Infrared Absorption) phenomenon. The first two solutions are costlier in comparison to the SERIA phenomenon because it is an inexpensive and efficient way to improve the interaction of light with matter. The key objective of this study was to develop, fabricate, and analyze a low-cost plasmonic substrate for attenuated total reflectance SEIRA (ATR-SEIRA). This is a highly effective method for detecting even the smallest quantities, including conformational flexibility, and improving the vibrational modes of compounds. We have used a FEM (finite element method) based wave optics module in the frequency domain (COMSOL Multiphysics) to numerically analyze plasmonic nanostructure based on a periodic gold Nano disk array to determine its sensitivity and tunability. We developed a numerical model using the Otto configuration to simulate the effect of a SEIRA substrate in ATR-SEIRA instrumentation’s (by including the “prism-effect” in the model). To validate the numerical method, self-assembled Nano-spheres lithography fabrication based SEIRA substrates are characterized using the scanning electron microscope (SEM) and ATR-FTIR (ATR-Fourier Transform IR) spectrometer. Furthermore, we have demonstrated the ATR-SEIRA phenomenon by fictionalizing the SEIRA substrate with a self-assembled bio-absorbed analyte 4-aminothiophenol (4-ATP) as monolayer. The outcomes obtained are in good agreement with the numerical analysis. As a standard benchmark, we have evaluated the performance of our realized SEIRA substrate by calculating the amplification factor, which amounts to 10^5. These results confirm the accuracy of numerical modelling and show that the proposed low-cost ATR-SEIRA substrates are repeatable, homogeneous, and can increase sensitivity. Overall, the proposed SEIRA substrate can be available tool for performing IR absorption spectral analyses, offering better performance compared to standard FTIR approaches.

Downloads

Downloads per month over past year

Actions (login required)

View Item View Item