FTIR (Fourier Transform Infrared) Spectroscopy

Infrared Spectroscopy with Fourier Transform (FTIR) is a spectroscopic technique that analyzes chemical structures by exploiting the interaction of molecules with infrared radiation. This method, organic and inorganic substances, particularly in identifying surface functional groups. The importance of FTIR in scientific research stems from its indispensable role in numerous disciplines including chemistry, biology, materials science and nanotechnology like.

Basic Principles of FTIR Spectroscopy

FTIR instruments operate using systems called interferometers. In this system, infrared light is passed through the sample, causing molecules to absorb the light at their specific vibrational frequencies. Since each functional group in a molecule has a unique infrared absorption pattern, the resulting spectrum constitutes a “chemical finger fingerprint.” The raw signal data can be converted into an interpretable spectrum through Fourier transformation.

ATR Technology (Attenuated Total Reflectance)

One of the most common used techniques in FTIR measurements is the ATR mode. This mode simplifies sample preparation and provides high sensitivity especially in surface analyses. It enables reliable data even for very thin film and surfaces such as nanostructures.

Applications

Chemistry and Materials Science

• Additives and filler components in polymers and plastics can be analyzed using FTIR.
• Surface chemistry of materials such as metal surfaces, thin films and ceramics can be determined.
• Changes or degradation in crystalline structures can be monitored.

Biology and Medicine

• The proportions of α-helix and β-sheet content in proteins can be determined.
• Characterization of cell membranes, lipid compositions and biomaterials is possible.
• It can be used for molecular diagnostics in clinical samples.

Pharmaceutical Technology

• Active ingredient identification and purity analysis of drugs can be performed.
• Interactions between components in solid formulations can be investigated.
• Structural integrity and stability of tablets can be observed.

Environmental Sciences

• Organic pollutants in air, water and soil samples can be identified.
• The surface chemistry of microplastics can be examined in detail using ATR-FTIR.
• Volatile organic compounds (VOCs) in the gas phase can be detected.

Use of FTIR in Nanotechnology

Nanomaterial Characterization

FTIR is one of the primary characterization tools for determining surface functional groups of nanomaterials. The functionalization processes of materials such as Carbon nanotubes, graphite oxide and MOFs can be monitored using FTIR spectra.

FTIR spectrum of graphene oxide: Presence of groups such as C=O, C–OH and C–O–C can be analyzed.

Polymer Nanocomposites

In nanoparticle-reinforced polymer matrices, formation and chemical vineyard can be detected with FTIR. In particular, whether nanoparticles are homogeneously dispersed can be inferred indirectly from FTIR spectra.

Biomedical Applications

In nanoparticle-based drug delivery systems, the mode of drug binding and structural integrity after loading are verified using FTIR. Additionally, characterization of surfaces used in biosensors can also be performed.

Advantages and Limitations

Advantages:

• Fast and non-destructive analysis
• Ability to work with small sample amounts
• Compatibility with solid, liquid and gas samples
• Integration with ATR module for surface analysis

Limitations:

• Low signal intensity at the nanoscale may reduce sensitivity
• Aqueous environments can mask IR absorption
• Peak overlap in complex mixtures can complicate spectral interpretation

Therefore, FTIR is typically used in conjunction with techniques such as Raman spectroscopy, XPS (X-ray Photoelectron Spectroscopy) and SEM/TEM combination.