Multiplexed plasmonic sensing based on small-dimension nanohole arrays and intensity interrogation

Area of Science:

• Nanophotonics
• Biosensing
• Surface science

Background:

• Nanohole array devices offer unique optical properties for sensing applications.
• Simultaneous detection of multiple molecular properties is crucial for comprehensive analysis.
• Distinguishing between absorption, scattering, and refractive index changes is challenging.

Purpose of the Study:

• To develop and demonstrate a multiplexed sensing platform using nanohole arrays.
• To simultaneously obtain information on molecular absorption, scattering, and refractive index changes.
• To validate the platform's performance with diverse analytes and identify experimental artifacts.

Main Methods:

• Fabrication of up to 25 distinct nanohole array structures within a small area (65 microm x 50 microm).
• Utilizing arrays with different optical behaviors to differentiate sensing signals.
• Performing multiplexed sensing experiments with solutions of NaCl, Coomassie blue, bovine serum albumin, and liposomes.
• Monitoring superwavelength holes or nanohole arrays with varying periodicity and hole diameters to detect artifacts.

Main Results:

• Demonstrated simultaneous measurement of molecular absorption, scattering, and refractive index changes.
• Successfully distinguished between different optical properties of various analytes.
• Identified and detected experimental artifacts, including those from light source fluctuations, sample injections, and aggregate-induced scattering.
• Provided real-time information on the local surface environment.

Conclusions:

• Multiplexed sensing on nanohole arrays is a viable approach for comprehensive molecular analysis.
• The developed platform effectively distinguishes between multiple sensing parameters.
• The method allows for the detection of experimental artifacts, improving data reliability.
• This technology holds promise for advanced real-time surface environment monitoring.