Locally functionalized short-range ordered nanoplasmonic pores for bioanalytical sensing.

Area of Science:

• * Nanophotonics and Plasmonics
• * Nanofabrication and Microfluidics
• * Biosensing and Bioanalysis

Background:

• * Nanoplasmonic sensors using nanoholes and nanoparticles offer comparable sensing performance.
• * Perforated metal films can integrate nanofluidic channels, enabling unique sensor designs.
• * Existing methods lack integrated nanofluidic networks with localized plasmonic activity.

Purpose of the Study:

• * To present a novel bioanalytical sensing concept using nanoplasmonic pores within a multilayer membrane.
• * To develop a fabrication scheme for parallel production of multiple sensor chips.
• * To demonstrate flow-through sensing of specific biorecognition reactions with high sensitivity and temporal resolution.

Main Methods:

• * Fabrication of short-range ordered nanoplasmonic pores (150 nm diameter) in a gold/silicon nitride multilayer membrane on a Si wafer.
• * Development of a material-specific surface modification to ensure selective binding on gold regions.
• * Monitoring plasmon resonance shifts to detect biorecognition events in a flow-through system.

Main Results:

• * Demonstrated parallel fabrication of over 50 sensor chips or 1000 membranes per wafer.
• * Achieved a two-dimensional nanofluidic network with localized plasmonic activity in nanochannels.
• * Showcased flow-through sensing with a signal-to-noise ratio of ~50 and temporal resolution <190 ms.
• * Demonstrated at least a 10-fold increase in uptake speed compared to stagnant conditions with minimal sample use.

Conclusions:

• * The developed nanoplasmonic sensor platform integrates nanofluidics and plasmonics for efficient bioanalysis.
• * The fabrication method allows for scalable and cost-effective production of sensor arrays.
• * This approach enables rapid, specific, and low-volume detection of biorecognition events.