Highly Sensitive and Selective Nanogap-Enhanced SERS Sensing Platform.

Area of Science:

• Materials Science
• Spectroscopy
• Nanotechnology

Background:

• Developing sensitive and selective analytical platforms is crucial for detecting trace amounts of toxic substances.
• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity but often requires complex sample preparation and specialized substrates.
• Plasmonic nanostructures are key to enhancing Raman signals, but their fabrication and integration into practical sensing devices remain challenging.

Purpose of the Study:

• To create a highly sensitive and selective SERS sensing platform.
• To develop a simple fabrication method for plasmonic nanostructures.
• To demonstrate selective molecular detection using SERS integrated with nanofiltration membranes.

Main Methods:

• Fabrication of plasmonic hotspots via direct maskless plasma etching of polymer surfaces.
• Assembly of high aspect ratio silver/polymer nanopillars driven by surface tension.
• Encapsulation of plasmonic nanostructures within nanofiltration membranes.
• Selective molecular filtration based on membrane swelling and molecular size.

Main Results:

• Achieved an average SERS enhancement factor of 1.5 × 10^7.
• Demonstrated selective filtration and detection of small molecules.
• Developed a SERS platform that does not require sample pretreatment.
• Showcased the potential for rapid detection of toxic molecules using portable Raman spectroscopy.

Conclusions:

• The developed plasmonic nanopillar-based SERS platform offers high sensitivity and selectivity.
• Integration with nanofiltration membranes enables size-based selective detection of molecules.
• The platform provides a simple, fast, and label-free method for toxic molecule detection.