Silica nanowire arrays for diffraction-based bioaffinity sensing.

Area of Science:

• Nanotechnology
• Materials Science
• Chemical Sensing

Background:

• Fabrication of large-area nanowire arrays is crucial for scalable sensor applications.
• Optical properties of nanostructures can be harnessed for sensitive detection.
• Developing efficient biosensors for medical diagnostics remains a key challenge.

Purpose of the Study:

• To develop and characterize large-area arrays of electrodeposited silica nanowires (SiO2 NWs).
• To investigate the use of these SiO2 NW arrays as optical sensors for refractive index and biomolecule detection.
• To demonstrate the potential of SiO2 NW arrays in medical diagnostics.

Main Methods:

• Fabrication of SiO2 NW arrays using photolithography and electrochemically triggered sol-gel deposition.
• Characterization using optical microscopy and scanning electron microscopy (SEM).
• Optical diffraction measurements in a prism-coupled total internal reflection geometry.

Main Results:

• Successfully fabricated cm(2) arrays of SiO2 NWs with controlled dimensions.
• Demonstrated bulk refractive index sensing with a sensitivity of 1.30×10(-5) RIU.
• Achieved diffraction biosensing of gold nanoparticles and streptavidin adsorption.
• Detected human α-thrombin at sub-pathologic nanomolar concentrations using functionalized SiO2 NW arrays.

Conclusions:

• Electrodeposited SiO2 NW arrays are a promising platform for sensitive optical sensing.
• The developed sensor arrays show potential for diverse applications, including medical diagnostics.
• Functionalization of SiO2 NWs enables specific and sensitive detection of target analytes.