Subwavelength nanostructures for optical biosensing and rapid photochemical reactions

Jin, Hyunjong

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https://hdl.handle.net/2142/31941 Copy

Description

Title

Subwavelength nanostructures for optical biosensing and rapid photochemical reactions

Author(s)

Jin, Hyunjong

Issue Date

2012-06-27T21:20:32Z

Director of Research (if dissertation) or Advisor (if thesis)

Liu, Gang Logan

Doctoral Committee Chair(s)

Liu, Gang Logan

Committee Member(s)

• Cunningham, Brian T.
• Kim, Kyekyoon
• Rogers, John A.
• Li, Xiuling

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Date of Ingest

2012-06-27T21:20:32Z

Keyword(s)

• subwavelength nanostructure
• photocatalytic
• surface enhanced Raman scattering (SERS)
• optical biosensor
• solar disinfection of water

Abstract

This thesis reports on the experimental examination of the use of nanostructures for three topics of light-matter interaction. First, enhanced photon absorption for photocatalytic reactions has been demonstrated. Photocatalytic metal nanoparticle synthesis is of significant interest in plasmonic biosening due to the simple fabrication capability. However, long synthesis time of more than 10 hours and the use of particle stabilization chemical agents hinder economical and rapid synthesis of such metal nanoparticle systems. We demonstrate a Si subwavelength nanostructure-based photochemical device. We show rapid photocatalytic structure transformation of noble metal nanoparticle ionization and reduction within 5 minutes with only pure water and room light illumination. Second, 3D nanostructures for optical biosensing have been investigated. We demonstrate optical spectroscopy by using subwavelength dielectric nanostructures as the substrate material for localized surface plasmon resonance metallic nanoparticles. Nanostructured substrates made of Si and Si3N4 have been characterized and compared. Schemes of enhancing the optical signal extraction are also discussed. We show the potential of dielectric based nanostructure substrate for applications in optical molecular sensing. Third, the experimental approaches from the two demonstrations are merged for photocatalytic nanoparticles. TiO2 nanoparticles are formed along the sidewall of subwavelength Si nanostructure. The dual semiconductor system is investigated for photocatalytic bacteria disinfection in water. We show disinfection of E. coli with just room light illumination on our proposed device. Possibilities of extending this device towards water splitting are also discussed. Each application is introduced with a brief motivation, description of the experimental method, and discussion of the results. Possible future directions are also presented.

Graduation Semester

2012-05

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http://hdl.handle.net/2142/31941

Copyright and License Information

Copyright 2012 Hyunjong Jin

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