Jung Heon Lee

Colorimetric uranium sensors based on uranyl (UO2(2+)) specific DNAzyme and gold nanoparticles (AuNP) have been developed and demonstrated using both labeled and label-free methods. In the labeled method, a uranyl-specific DNAzyme was attached to AuNP, forming purple aggregates. The presence of uranyl induced disassembly of the DNAzyme functionalized AuNP aggregates, resulting in red individual AuNPs. Once assembled, such a "turn-on" sensor is highly stable, works in a single step at room temper

Although transmission electron microscopy (TEM) may be one of the most efficient techniques available for studying the morphological characteristics of nanoparticles, analyzing them quantitatively in a statistical manner is exceedingly difficult. Herein, we report a method for mass-throughput analysis of the morphologies of nanoparticles by applying a genetic algorithm to an image analysis technique. The proposed method enables the analysis of over 150,000 nanoparticles with a high precision of

Going for double gold: Precise control of the positions of and distances between gold nanoparticles (AuNP; gold spheres in picture) is achieved by linking the AuNPs to phosphorothioate-modified DNA (green and red helices) with a bifunctional fastener. The distance between AuNPs is controlled simply by changing the position of the modifications on the DNA template. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z702569_s.pdf or

Considering that both bovine bone grafting materials have been successfully used in oral surgery applications in the last few decades, this work shows that the porcine-derived grafting material possesses most of the key physiochemical characteristics required for its application as a highly efficient xenograft material for bone replacement.

Controlled alignment of streptavidin (STV), myoglobin, and nanoparticles with nanometer resolution has been achieved via backbone-modified phosphorothioate DNA and biotin- and maleimide-containing bifunctional linkers. Introducing triplet biotin modifications in three adjacent PSs significantly increased the STV conjugation yield. By placing phosphorothioate modifications at multiple positions of a double stranded DNA template, monomer, dimer, and trimer STV-DNA assemblies were formed with the S

We demonstrate a strategy for the synthesis of discrete and uniform gold nanorod (GNR)@mesoporous silica (mSiO2) core–shell nanoparticles (NPs) with finely tuned shell thickness by significantly suppressing the formation of undesired core-free NPs. We could control the thickness of the mSiO2 shell with high precision, close to 1 nm, and hence the rotational diffusion mode of NPs by simply controlling the silica precursor injection times. The growth of the mSiO2 shell on the GNR seeds and the for

As Mo₃Se₃^- chain nanowires have dimensions comparable to those of natural hydrogel chains (molecular-level diameters of ∼0.6 nm and lengths of several micrometers) and excellent mechanical strength and flexibility, they have large potential to reinforce hydrogels and improve their mechanical properties. When a Mo₃Se₃^--chain-nanowire-gelatin composite hydrogel is prepared simply by mixing Mo₃Se₃^- na

Although carbon nanotubes (CNTs) are remarkable materials with many exceptional characteristics, their poor chemical functionality limits their potential applications. Herein, a strategy is proposed for functionalizing CNTs, which can be achieved with any functional group (FG) without degrading their intrinsic structure by using a deoxyribonucleic acid (DNA)-binding peptide (DBP) anchor. By employing a DBP tagged with a certain FG, such as thiol, biotin, and carboxyl acid, it is possible to intr