Atomically Thin TaSe₂ Film as a High-Performance Substrate for Surface-Enhanced Raman Scattering

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman scattering (SERS) is a powerful technique for molecular detection.
• Atomically thin 2D materials offer unique properties for SERS substrates.
• Tantalum diselenide (TaSe2) has not been previously explored for SERS applications.

Purpose of the Study:

• To synthesize and characterize atomically thin TaSe2 nanosheets.
• To investigate the SERS performance of TaSe2 for detecting Raman-active molecules.
• To elucidate the mechanism behind TaSe2's SERS enhancement and explore its diagnostic potential.

Main Methods:

• Synthesis of 2-3 layer TaSe2 nanosheets (2.5 cm diameter).
• Characterization using spectrum analysis.
• Theoretical investigation using density functional theory (DFT).
• Detection of rhodamine 6G and bilirubin in biological samples.

Main Results:

• Achieved a limit of detection of 10^-10 M for rhodamine 6G.
• Identified large adsorption energy and high electron density near the Fermi level as key to chemical enhancement.
• Demonstrated sensitive detection of bilirubin in serum and urine samples.

Conclusions:

• Atomically thin TaSe2 exhibits excellent SERS performance.
• The mechanism involves significant chemical enhancement due to electronic properties.
• TaSe2-based SERS substrates hold potential for clinical diagnostics, such as jaundice detection in newborns.