SERS-Based Hydrogen Bonding Induction Strategy for Gaseous Acetic Acid Capture and Detection

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Gaseous small-molecule detection faces limitations like complex processes and harsh conditions.
• Real-time gas sensing at room temperature requires overcoming challenges in low adsorption and small Raman scattering cross sections.

Purpose of the Study:

• To develop a Surface-Enhanced Raman Scattering (SERS)-based strategy for capturing and sensing gaseous acetic acid.
• To enable the first SERS-based detection of gaseous acetic acid using a portable Raman spectrometer.
• To address challenges of low adsorption and small Raman scattering cross sections for small gas molecules.

Main Methods:

• Utilized a SERS-based hydrogen bonding induction strategy.
• Modified a SERS substrate with 4-mercaptobenzoic acid (4-MBA) as a ligand molecule.
• Employed experimental spectroscopy and density functional theory (DFT) to confirm hydrogen bond-induced trapping.
• Developed an analytical method based on direct response hydrogen bond formation (I_O-H/I_ref).

Main Results:

• Achieved highly sensitive and reliable detection with a sensing chip exhibiting a low relative standard deviation (RSD) of 4.15%.
• Enabled detection of gaseous acetic acid at concentrations as low as 60 ppb.
• Demonstrated superior anti-interference capability in simulated breath and wine detection systems.
• Confirmed hydrogen bond-induced acetic acid trapping through experimental and theoretical analyses.

Conclusions:

• The proposed SERS strategy effectively overcomes limitations in gaseous small-molecule detection.
• The developed method allows for highly sensitive, reliable, and real-time sensing of gaseous acetic acid.
• The high reusability of the sensing chip indicates significant potential for practical applications.