Alternative TitleStudies on a localized surface plasmon resonance optical fiber sensor with picoliter volume for biological sensing
Note (General)In this thesis, a spectrometer cell with a sensing volume of sub-picoliter has been fabricated inside a glass optical fiber by use of near ultraviolet (NUV) femtosecond laser pulses. By use of the cell with a small sensing volume, spectroscopic measurements using localized surface plasmon resonance (LSPR) were demonstrated. The parameters of the laser system in order to make a micro through-hole inside a glass optical fiber were optimized. The microhole worked as an inline/picoliter spectrometer cell, which had capability of measuring refractive indices of liquid samples by using a combination of a halogen white light source and a compact CCD spectrometer. The spectrometer cell was fabricated into an optical glass fiber by focusing the NUV femtosecond laser pulses at a wavelength of 400 nm with an energy of 30 μJ. The laser beam was focused from two directions opposite to each other to fabricate a micro through-hole spectrometer cell. A diameter of the cell was approximately 3 μm, and the length was approximately 62.5 μm, which was nearly equal to the core diameter of the optical fiber. Absorption spectra using LSPR were obtained with the spectrometer cell. Liquid solution of gold nanoparticles (GNPs) with a diameter of 5 to 10 nm was injected into the spectrometer cell with the volume of 0.4 pL. The absorption peak centered at 518 nm was observed. An increase of the absorption associated with the increase of the number of nanoparticles was in agreement with the numerical calculation based on the Lambert-Beer law. An aggregation of GNPs caused by biomolecules of L-cysteine was monitored by the change in the absorption spectra. The absorption peak of LSPR disappeared due to an injection of 7.5 mM of L-cysteine. The detection sensitivity of L-cysteine was calculated to be 3.0×10-15 mol (3.6×10-13 g) in the spectrometer cell due to the interaction volume of 0.4 pL with the 7.5 mM L-cysteine. A novel spectroscopic measurement method has been established that enables biomolecules to be detected in a simple measurement configuration with a small absolute amount of sensing targets.
Collection (particular)国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文
Date Accepted (W3CDTF)2023-10-11T15:41:03+09:00
Data Provider (Database)国立国会図書館 : 国立国会図書館デジタルコレクション