Multifunctional Paper Strip Based on Self-Assembled Interfacial Plasmonic Nanoparticle Arrays for Sensitive SERS...

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Materials Science

Background:

• Surface-enhanced Raman spectroscopy (SERS) offers high sensitivity for chemical detection.
• Paper-based devices are attractive for portable and low-cost sensing applications.
• Integrating nanomaterials onto paper can enhance sensing capabilities.

Purpose of the Study:

• To develop a multifunctional paper-based SERS sensing card.
• To achieve highly sensitive and rapid detection of analytes.
• To create a practical and portable sensing platform for real-world applications.

Main Methods:

• Patterning self-assembled interfacial arrays of gold nanoparticles (AuNPs) on an arrow-shaped paper strip.
• Utilizing the paper card's capillary force and polarity differences for analyte separation and preconcentration.
• Employing SERS for sensitive detection of analytes.

Main Results:

• A closely packed monolayer of AuNPs was evenly distributed on the paper surface, creating numerous SERS hot spots.
• The paper card enabled sub-attomolar (50 × 10(-18) M) detection from 10 μL samples.
• The sensing card demonstrated a lithography-free preparation, fast detection (<5 min), and low cost (<3 cents).

Conclusions:

• The developed paper-based SERS sensing card is a smart, multifunctional, and integrated sensing platform.
• The device offers a practical and portable solution for sensitive environmental and food analysis.
• The low cost and ease of use make it suitable for wide-scale applications.