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Ik-Bum Kim

Publications and source records attributed to Ik-Bum Kim.

4 recordsLinked to original sources
PubMed2006

Modulating the sensory response of a conjugated polymer by proteins: an agglutination assay for mercury ions in water.

The complexes of a carboxylate-substituted poly(para-phenyleneethynylene) (PPE) with histone, bovine serum albumin, and papain were investigated. At higher concentrations, the proteins have a significant effect on the emission characteristics of the PPE. The electrostatic complexes formed from the PPE, and the proteins are agglutinated by different metal cations. The observed selectivities and sensitivities of these simple systems are most unusual; combination of the carboxylate-PPE and commercially available papain forms an electrostatic complex that is precipitated by mercury ions at concentrations above 10-5 mol L-1.

Alkynes↗
PubMed2005

Nonspecific interactions of a carboxylate-substituted PPE with proteins. A cautionary tale for biosensor applications.

Two carboxylate-substituted, fluorescent (Phi = 0.08), water-soluble poly(p-phenyleneethynylene)s (PPE) and a water-soluble model compound were exposed to a series of proteins and bovine serum. While the anionic PPEs do not have any specific binding sites, they form stable complexes with histone, lysozyme, myoglobin, and hemoglobin. The complex formation was evidenced by fluorescence quenching. Bovine serum albumin does not quench the fluorescence of the PPEs but enhances it, probably due to its surfactant character. These results imply that the use of charged conjugated polymers as biosensors, while an attractive proposition, has to take into account strong nonspecific interactions between conjugated polymers and the host of proteins that is found in cells and complex biological fluids.

Alkynes↗
PubMed2004

Sugar-poly(para-phenylene ethynylene) conjugates as sensory materials: efficient quenching by Hg2+ and Pb2+ ions.

Three polar poly(para-phenylene ethynylene)s (PPE) were synthesized by utilizing the Heck-Sonogashira protocol. Two of the PPEs carry beta-glucopyranose substituents. Depending upon the linker used between the glycol units and the backbone, the fluorescence of these PPEs can be quenched by Hg2+ and Pb2+ to a varying degree. Monomeric model compounds that are substituted with only one glucose unit are not efficiently quenched. The presence of many glucose substituents in one PPE assembly led to a large increase in the binding constant to Hg2+ and quenching of the fluorescence was amplified.

Alkynes↗