Monitoring molecule translocation through plasmonic nanopores based on surface enhanced Raman scattering

Area of Science:

• Nanotechnology
• Surface Science
• Spectroscopy

Background:

• Understanding molecule translocation through nanopores is crucial for developing advanced sensing and separation technologies.
• Gold plasmonic nanopores (GPNs) offer unique optical properties for sensitive detection.
• Surface Enhanced Raman Scattering (SERS) provides high-resolution molecular information.

Purpose of the Study:

• To investigate the translocation behavior of molecules through GPNs.
• To explore the influence of electrostatic effects, concentration, and pH on molecule translocation.
• To characterize the dynamics of single molecule translocation events.

Main Methods:

• Fabrication of gold plasmonic nanopores (GPNs) with high Raman activity.
• Utilizing Surface Enhanced Raman Scattering (SERS) to monitor molecule translocation.
• Controlling translocation parameters such as potential, concentration, and pH.

Main Results:

• The electrostatic effect was identified as a critical factor determining the direction and speed of model molecule translocation.
• Characteristic blinking signals of rhodamine 6G (R6G) molecules were observed during translocation.
• High temporal resolution (millisecond) was achieved in observing single molecule events.

Conclusions:

• GPNs combined with SERS are effective tools for studying molecule translocation dynamics.
• Electrostatic interactions play a significant role in controlling molecular transport through nanopores.
• The observed blinking signals provide insights into the transient interactions of molecules within nanopores.