Hyun Gyu Park

alpha-chymotrypsin (CT) and lipase (LP) were immobilized in hierarchically-ordered mesocellular mesoporous silica (HMMS) in a simple but effective way for the enzyme stabilization, which was achieved by the enzyme adsorption followed by glutaraldehyde (GA) crosslinking. This resulted in the formation of nanometer scale crosslinked enzyme aggregates (CLEAs) entrapped in the mesocellular pores of HMMS (37 nm), which did not leach out of HMMS through narrow mesoporous channels (13 nm). CLEA of alph

DNA, a biological shield: A new and simple colorimetric strategy for the detection of nucleic acids relies on target-DNA-induced shielding against the peroxidase-mimicking activity of magnetic nanoparticles. The viability of this simple yet efficient colorimetric detection system is demonstrated by its application to the diagnosis of the Chlamydia trachomatis pathogen using a human urine sample.

Metal ion, an astonishing illusionist: In a new concept, “illusionary” polymerase activity is intentionally triggered at T–T and C–C mismatched primers by Hg2+ and Ag+ ions, respectively. A novel strategy to construct molecular-scale logic gates utilizes the nonnatural polymerase activity induced by the metal ions by rational design of the primers and selection of the type of DNA polymerase (see picture). Detailed facts of importance to specialist readers are published as ”Supporting Information

A nanostructured multicatalyst system consisting of Fe(3)O(4) magnetic nanoparticles (MNPs) as peroxidase mimetics and an oxidative enzyme entrapped in large-pore-sized mesoporous silica has been developed for convenient colorimetric detection of biologically important target molecules. The construction of the nanocomposites begins with the incorporation of MNPs on the walls of mesocellular silica pores by impregnating Fe(NO(3))(3)·9H(2)O, followed by the immobilization of oxidative enzymes. Glu

Abstract A universal colorimetric method for the detection of nucleic acids, based on ionic interactions by polydiacetylene (PDA) liposomes, is described. Primary and quaternary amine‐modified diacetylene monomers were synthesized and used to generate positively charged PDA liposomes. The resulting PDA sensors showed a dramatic color change from blue to red upon the addition of nucleic acids amplified by using the polymerase chain reaction (PCR) due to the stimuli caused by ionic interactions be

Enzyme-linked immunosorbent assays (ELISAs) have most widely been applied in immunoassays for several decades. However, several unavoidable limitations (e.g., instability caused by structural unfolding) of natural enzymes have hindered their widespread applications. Here, we describe a new nanohybrid consisting of Fe₃O₄ magnetic nanoparticles (MNPs) and platinum nanoparticles (Pt NPs), simultaneously immobilized on the surface of graphene oxide (GO). By synergistically integrating highly catalyt

A new platform technology is herein described with which to construct molecular logic gates by employing the hairpin-structured molecular beacon probe as a basic work unit. In this logic gate operation system, single-stranded DNA is used as the input to induce a conformational change in a molecular beacon probe through a sequence-specific interaction. The fluorescent signal resulting from the opening of the molecular beacon probe is then used as the output readout. Importantly, because the logic

A label-free colorimetric method to detect nucleic acids, which relies on target DNA induced shielding of the oxidase activity of CeO2 NPs, is developed. With this novel strategy, target nucleic acids can be identified within a few minutes and without the need for post-purification of PCR products.