Kangtaek Lee

Diffraction from a photonic crystal material composed of a hydrolyzed polymerized crystalline colloidal array (PCCA) can be used to sense pH and ionic strength. The PCCA is a polyacrylamide hydrogel which embeds a polystyrene crystalline colloidal array (CCA). The diffracted wavelength of the PCCA changes as the PCCA volume changes due to the alterations in the CCA lattice constant. We examine the pH and ionic strength dependence of the hydrolyzed PCCA volume by monitoring the Bragg diffracted w

The size of gold nanoparticle aggregates was controlled by manipulating the interparticle interaction. To manipulate the interparticle interaction of gold nanoparticles prepared by citrate reduction, we applied the substitutive adsorption of benzyl mercaptan on the particle surface in the absence of the cross-linking effect. Various experimental techniques such as UV-vis absorption spectroscopy, surface-enhanced Raman scattering, quasi-elastic light scattering, and zeta-potential measurement wer

Detection of single point mutation based on the hybridization of oligonucleotides was performed using unmodified gold nanoparticles. The sequences of oligonucleotides were designed to detect the metastatic efficiency modifier signal-induced proliferation-associated gene 1 ( Sipa1 ). The detection step was monitored using UV−vis absorption spectroscopy, quasielastic light scattering, and zeta potential measurement. We observed that addition of DNAs into the suspension of unmodified gold nanoparti