SERS Gas Sensors Based on Multiple Polymer Films with High Design Flexibility for Gas Recognition

Area of Science:

• Analytical Chemistry
• Materials Science
• Chemical Sensing

Background:

• Surface-Enhanced Raman Scattering (SERS) offers high sensitivity and rapid detection for gas sensing.
• Discriminating between gases with similar molecular structures is challenging for conventional SERS sensors due to spectral overlap.
• Developing advanced SERS sensor arrays is crucial for enhanced gas recognition capabilities.

Purpose of the Study:

• To develop a multiple SERS gas sensor matrix for improved recognition of gases with similar molecular structures.
• To utilize functional polymers and a layer-by-layer method for creating versatile SERS sensor films.
• To demonstrate the effectiveness of a combined SERS sensor array and principal component analysis (PCA) for gas discrimination.

Main Methods:

• Fabrication of SERS sensor films using spin-coating of functional polymers: Poly(acrylic acid) (PAA), Poly(methyl methacrylate) (PMMA), and Polydimethylsiloxane (PDMS).
• Construction of a multi-layer sensor matrix using a layer-by-layer deposition technique for enhanced design flexibility.
• Application of the Principle Component Analysis (PCA) algorithm to analyze response matrices from single-layer and two-layer film-coated sensors.

Main Results:

• SERS sensors coated with different polymer films exhibited distinct affinities towards target gases.
• A response matrix was constructed by combining gas responses from single-layer and two-layer film-coated sensors.
• Three target gases (phenethyl alcohol, acetophenone, and anethole) with similar molecular structures were perfectly discriminated using the developed sensor matrix and PCA.

Conclusions:

• The proposed multiple SERS gas sensor matrix effectively enhances gas recognition capabilities, particularly for molecules with similar structures.
• The layer-by-layer fabrication method provides high design flexibility for creating tailored SERS sensor arrays.
• This research presents a promising new SERS sensing strategy for complex gas mixture analysis and identification.