Heesang Ahn

A Localized Surface Plasmon Resonance Sensor Using Double-Metal-Complex Nanostructures and a Review of Recent Approaches

From active developments and applications of various devices to acquire outside and inside information and to operate based on feedback from that information, the sensor market is growing rapidly. In accordance to this trend, the surface plasmon resonance (SPR) sensor, an optical sensor, has been actively developed for high-sensitivity real-time detection. In this study, the fundamentals of SPR sensors and recent approaches for enhancing sensing performance are reported. In the section on the fundamentals of SPR sensors, a brief description of surface plasmon phenomena, SPR, SPR-based sensing applications, and several configuration types of SPR sensors are introduced. In addition, advanced nanotechnology- and nanofabrication-based techniques for improving the sensing performance of SPR sensors are proposed: (1) localized SPR (LSPR) using nanostructures or nanoparticles; (2) long-range SPR (LRSPR); and (3) double-metal-layer SPR sensors for additional performance improvements. Consequently, a high-sensitivity, high-biocompatibility SPR sensor method is suggested. Moreover, we briefly describe issues (miniaturization and communication technology integration) for future SPR sensors.

Recent advances of nanostructure implemented spectroscopic sensors—A brief overview

ABSTRACT By the conjugation of requirements of high-performance sensing platforms and developments of nanotechnology, various nanostructure implemented photonic, spectroscopic sensors have been investigated. In this review article, we address 3 types of nanostructure implemented optical sensor techniques—localized surface plasmon resonance (LSPR) sensors, extraordinary optical transmission (EOT) based sensors, and Raman-based spectroscopic sensors—and recent advances of the nanostructure assisted sensors arranged by 2 important issues: the employment of novel nanostructures and the application of newly investigated fabrication techniques for larger sensing area.

Emerging optical spectroscopy techniques for biomedical applications—A brief review of recent progress

ABSTRACT Optical measurement methods are widely employed in both industrial and medical fields for two reasons: (1) they are non-invasive and (2) they have a high resolution. Among the various optical methods currently available, those based on spectroscopy are actively employed to monitor multiple factors using spectral information. In this review article, three categories of optical spectroscopic methods for biomedical diagnosis are discussed: (1) in vitro preclinical diagnosis using optical spectroscopy, (2) non-invasive early-stage diagnosis based on optical spectroscopy at the surface of the skin and (3) minimally-invasive diagnosis using spectroscopy-integrated endoscopies. We also highlight the advances in nanomaterials, molecular probes, and photonic system constructions that have led to improvements in the sensitivity, diagnostic speed, and capability to analyze multiple medical parameters. Additionally, we briefly discuss the future prospects of these spectroscopic applications and the combination of optical techniques with information technology.

Plasmon-Coupled Whispering Gallery Modes on Nanodisk Arrays for Signal Enhancements

Metallic nanostructures including single and double nanodisks are successfully used to enhance the localized electric field in vicinity of microcavity in whispering gallery mode (WGM) sensor. We demonstrate numerical calculations of plasmonic coupling of WGMs to single and double nanodisk arrays on a planar substrate. We then experimentally confirmed that the resonance wavelength of WGM sensor was dramatically shifted by adoption of single and double nanodisks on the surface of microcavity in the WGM sensor. Thus, our approach provides the tunable sensitivity of WGM sensor, and has a great potential to be used in numerous areas where the single biomolecule, protein-protein folding and biomolecular interactions are involved.

Gap plasmonic effects of gold nanoparticles on metallic film

The effective confinement of light in a deep-subwavelength volume can be achieved in metallic nanostructures through the electronic resonance, surface plasmons (SPs). There are few ways to enhance the localization of the field such as adopting metallic nanopost or nanowire structures on the precious metallic film. The achieved highly enhanced field localization through SPs can be exploited for surface-enhanced spectroscopy, biosensor, enhancing energy emitter, and enhanced energy generator. Also, many researches have been tried with few-nanometer gap between the metals for achieving large field enhancements. In this paper, by comparing the scattering of gold nanoparticles, the effects of metallic film of substrates were investigated through simulation. In addition, as changing of the gap between gold nanoparticle and metallic surface, different resonance wavelengths were observed in scattering spectra from simulation and practical experiments. We confirmed that the gold film with gold nanoparticles shows the most distinctive scattering spectra. The numerical demonstration was matched with our experimental demonstration, also with the previously introduced papers as well.

Estimation of Sensitivity Enhancements on Localized Surface Plasmon Resonance Sensor Using Dielectric Multilayer

본 논문에서는 LSPR 센서에 적용하기 위한 제한된 높이 100 nm에서

Estimation of Sensitivity Enhancements of Material-Dependent Localized Surface Plasmon Resonance Sensor Using Nanowire Patterns

TiO_2

Concentration measurement of LDL cholesterol using extraordinary optical transmission sensor

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Rapid and real-time diagnosis of hypoalbuminemia using an extraordinary optical transmission biosensor

SiO_2

A Fabrication of Nanostructures with a Transmission Light and a Plasmonic Field at Different Z-axis Position

의 다중층을 이용한 LSPR 센서를 디자인을 제안했다. LSPR 센서의 구조는 유전체 층과 나노 구조가 있는 금속층으로 디자인 하였다. 금속층은 금 박막 40 nm와 높이 40 nm, 주기 600 nm, 선폭 300 nm인 나노와이어 구조체를 올려놓...