Taewook Kang

A noble metal ion (Pt 2+ and Pd 2+ ) adsorbent with uniform mesopore channels was prepared by grafting a thiol functional group, (3-mercaptopropyl)trimethoxysilane (MPTMS), onto ordered mesoporous silica, SBA-15. Results show that the ordered mesostructure of SBA-15 was retained after modification and the thiol functional group was immobilized mainly inside the mesopore channel, as evidenced by Brunauer−Emmett−Teller surface area, small-angle X-ray scattering, Fourier transform infrared, and ele

Organic ligand containing the imidazole [N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole], precious metal-chelating functionality, was immobilized on the surface of ordered mesoporous silica, SBA-15. The resulting functionalized ordered mesoporous silica (Imi-SBA-15) was characterized and tested as an effective adsorbent for Pt2+ and Pd2+. N2 adsorption/desorption measurements and small angle X-ray scattering spectroscopy (SAXS) demonstrate both the maintenance of pore symmetry (space group p6mm

A facile preparation of ultrasmall 1-2 nm void metallic nanogaps on various solid substrates is proposed by utilizing the self-assembly of a uniform gold-silica core-shell nanoparticle monolayer at interfaces and chemical etching. The ultrasmall void metallic nanogap shows key advantages such as a strong near-field enhancement and free diffusion of analytes to the gap, which are useful in molecular sensing and monitoring.

Hybrid liposome/metal nanoparticles are promising candidate materials for biomedical applications. However, the poor selectivity and low yield of the desired hybrid during synthesis pose a challenge. We designed a programmable liposome by selective encoding of a reducing agent, which allows self-crystallization of metal nanoparticles within the liposome to produce stable liposome/metal nanoparticles alone. We synthesized seven types of liposome/monometallic and more complex liposome/bimetallic h

We report core-satellites (Au-Ag) coupled plasmonic nanoassemblies based on bottom-up, high-density assembly of molecular-scale silver nanoparticles on a single gold nanoparticle surface, and demonstrate direct observation and quantification of enhanced plasmon coupling (i.e., intensity amplification and apparent spectra shift) in a single particle level. We also explore metal ion sensing capability based on our coupled plasmonic core-satellites, which enabled at least 1000 times better detectio

Controlled assembly of colloidal nanoparticles onto solid substrates generally needs to overcome their thermal diffusion in water. For this purpose, several techniques that are based on chemical bonding, capillary interactions with substrate patterning, optical force, and optofluidic heating of light-absorbing substrates are proposed. However, the direct assembly of colloidal nanoparticles on generic substrates without chemical linkers and substrate patterning still remains challenging. Here, ph

The importance of the photothermal effect in surface enhanced Raman scattering (SERS) measurements is addressed. Strong temperature gradient (≈106 K m−1) induced by photothermal effect can force molecules to move. Finally, redistributed molecules can result in a nonuniform SERS intensity. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the author

A new class of surface-immobilized protein nanomachines can be reversibly actuated by cycling the solution pH between 2.5 and 12.3, which induces a conformational change, thereby modulating the thickness of superoxide dismutase (SOD1) tethered to the Au thin film. By placing Au nanoparticles (AuNP) atop the immobilized SOD1 by means of a gold-thiol assembly, the nanoscale motion of SOD1 at the interface produces mechanical work to lift and then lower the AuNP from the Au substrate by a distance

Objective: To assess the safety and therapeutic efficacy of a percutaneous radiofrequency (RF) ablation for the hepatocellular carcinoma (HCC) abutting the diaphragm. Materials and Methods: We retrospectively assessed 80 patients who underwent a percutaneous RF ablation for a single nodular (< 4 cm) HCC over the last four years. Each patient underwent an ultrasound-guided RF ablation using internally cooled electrodes for the first-line treatment. We divided patients into two subgroups based on

Owing to its high sensitivity and high selectivity along with rapid response time, plasmonic detection has gained considerable interest in a wide variety of sensing applications. To improve the fieldwork applicability and reliability of plasmonic detection, the integration of plasmonic nanoparticles into optical devices is desirable. Herein, we propose an integrated label-free detection platform comprising a plasmonic cavity that allows sensitive molecular detection via either surface-enhanced R

Abstract: Low-Energy Adaptive Clustering Hierarchy (LEACH) is one of the most popular distributed cluster-based routing protocols in wireless sensor networks. Clustering algorithm of the LEACH is simple but offers no guarantee about even distribution of cluster heads over the network. And it assumes that each cluster head transmits data to sink over a single hop. In this paper, we propose a new method for selecting cluster heads to evenly distribute cluster heads. It avoids creating redundant cl

Abstract A rapid, precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment. However, conventional methods, such as culture-based counting, generally suffer from slow detection times and low sensitivities. Here, we developed a rapid detection method for tracing waterborne pathogens by an innovative optofluidic platform, a plasmonic bacteria on a nanoporous mirror, that allows effective hydrodynamic cell trapping, enrichment of pathog

Self-formation of colloidal oil droplets in water or water droplets in oil not only has been regarded as fascinating fundamental science but also has been utilized in an enormous number of applications in everyday life. However, the creation of three-dimensional (3D) architectures by a liquid droplet and an immiscible liquid interface has been less investigated than other applications. Here, we report interfacial energy-driven spontaneous self-formation of a 3D plasmonic optical structure at roo