Double-sided plasmonic metasurface for simultaneous biomolecular separation and SERS detection

Area of Science:

• Biotechnology
• Nanotechnology
• Spectroscopy

Background:

• Porous membranes are crucial for biomolecule separation, with size selectivity being a key performance metric.
• Accurate detection methods are needed for on-membrane examination of size selectivity.
• Surface-Enhanced Raman Spectroscopy (SERS) offers ultrasensitive, trace-level detection capabilities.

Purpose of the Study:

• To develop a novel double-sided hierarchical porous membrane-like plasmonic metasurface.
• To achieve high-selectivity bimolecular separation and simultaneous ultrasensitive SERS detection.
• To create a flexible device for molecular filtration and detection under complex conditions.

Main Methods:

• Fabrication of a membrane with subwavelength nanocone pairs and sub-5 nm nanogrooves.
• Utilizing "top-down" fabrication of conical nanopores and self-assembly of nanogrooves.
• Employing a cascaded electromagnetic near-field enhancement mechanism for SERS.

Main Results:

• Demonstrated effective nanofiltration separation of adenine from ss-DNA based on size.
• Achieved ultrasensitive SERS detection of 4-mercaptopyridine down to 10 pM.
• Exhibited high sensitivity, uniformity, repeatability, and polarization independence in SERS detection.

Conclusions:

• The developed plasmonic metasurface membrane enables simultaneous high-selectivity separation and ultrasensitive detection of biomolecules.
• The device's mechanical flexibility and performance make it suitable for real-world applications.
• This technology holds significant potential for advanced molecular filtration and detection systems.