Identifier

etd-05182016-121901

Degree

Doctor of Philosophy (PhD)

Department

Electrical and Computer Engineering

Document Type

Dissertation

Abstract

Raman scattering is a well-known technique for detecting and identifying complex molecular level samples. The weak Raman signals are enormously enhanced in the presence of a nano-patterned metallic surface next to the specimens. This dissertation describes a technique to fabricate a novel, low cost, high sensitive, disposable, and reproducible metallic nanostructure on a transparent substrate for Surface Enhanced Raman Scattering (SERS). Raman signals can be obtained from the specimen surface of opaque specimens. Most importantly, the metallic nanostructure can be bonded on the end of a probe / a needle, and the other end is coupled to a distant spectrometer. This opens up the Raman spectroscopy for a use in a clinical environment with the patient simply sitting or lying near a spectrometer. This SERS system, one of molecular level early diagnosis technologies, can be divided into four parts: SERS nanostructure substrates, reflection Raman signal (in vitro), transmission (in vivo) Raman signal, and a probe / a needle with a gradient-index (GRIN) lens in an articulated arm system. In this work, the aluminum metal was employed as not only a base substrate for a sputtered Au nanostructure (conventional view) but also a sacrificial layer for the Au nanostructure on a transparent substrate (transmission view). The enhanced Raman Signal from reflection and transparent SERS substrates depended on aluminum etching methods, Au deposition angles, and Au deposition thicknesses. Rhodamine 6G solutions on both sides of the SERS substrates were used to analyze and characterize. Moreover, preliminary Raman Spectra from R6G and chicken specimen were obtained through a remote SERS probe head and an articulated arm system. The diameter of the invasive probe head was shrunk to 0.5 mm. The implication is that this system can be applied in medical applications.

Date

2016

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Feldman, Martin

DOI

10.31390/gradschool_dissertations.498

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