Electrostatic enrichment at nanoporous hotspots: A general strategy for charge-selective SERS detection in complex...

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Electrochemistry

Background:

• Controllable nanostructures and molecular orientation are crucial for advancing surface-enhanced Raman spectroscopy (SERS).
• Existing SERS methods face challenges in achieving efficient enhancement and ultrasensitive detection.

Purpose of the Study:

• To develop a sensitive detection strategy for thiacloprid (THIA) using a novel substrate and electrochemical approach.
• To enhance SERS performance through controllable nanostructures and tunable molecular adsorption.

Main Methods:

• Fabrication of nanoporous silver-gold substrate (pAg-Au-SPE) with tunable pore sizes.
• Implementation of a pH-regulated electrostatic capture electrochemical SERS (EC-SERS) strategy.
• Protonation of THIA under acidic conditions and electrostatic enrichment on the negatively charged substrate.

Main Results:

• Achieved controllable nanostructures with dense, uniformly distributed hotspots on pAg-Au-SPE.
• Demonstrated enhanced SERS signals due to perpendicular adsorption of protonated THIA.
• EC-SERS strategy achieved a 1.36 nM detection limit for THIA, three orders of magnitude lower than conventional SERS.

Conclusions:

• The developed EC-SERS strategy offers ultrasensitive detection of THIA.
• The approach provides a new perspective for the sensitive detection of diverse hazardous analytes.
• This work advances SERS applications for enhanced detection capabilities.