Dal Hee Min

Graphene has unique mechanical, electronic, and optical properties, which researchers have used to develop novel electronic materials including transparent conductors and ultrafast transistors. Recently, the understanding of various chemical properties of graphene has facilitated its application in high-performance devices that generate and store energy. Graphene is now expanding its territory beyond electronic and chemical applications toward biomedical areas such as precise biosensing through

Carbon-based materials, including graphene and carbon nanotubes, have been considered attractive candidates for biomedical applications such as scaffolds in tissue engineering, substrates for stem cell differentiation, and components of implant devices. Despite the potential biomedical applications of these materials, only limited information is available regarding the cellular events, including cell viability, adhesion, and spreading, that occur when mammalian cells interface with carbon-based

Among various nanoparticles, the silica nanoparticle (SiNP) is an attractive candidate as a gene delivery carrier due to advantages such as availability in porous forms for encapsulation of drugs and genes, large surface area to load biomacromolecules, biocompatibility, storage stability, and easy preparation in large quantity with low cost. Here, we report on a facile synthesis of monodispersed mesoporous silica nanoparticles (MMSN) possessing very large pores (>15 nm) and application of the na

MicroRNA (miRNA) is an important small RNA which regulates diverse gene expression at the post-transcriptional level. miRNAs are considered as important biomarkers since abnormal expression of specific miRNAs is associated with many diseases including cancer and diabetes. Therefore, it is important to develop biosensors to quantitatively detect miRNA expression levels. Here, we develop a nanosized graphene oxide (NGO) based miRNA sensor, which allows quantitative monitoring of target miRNA expre

Photosensitizers (PSs) are light‐sensitive molecules that are highly hydrophobic, which poses a challenge to their use for targeted photodynamic therapy. Hence, considerable efforts have been made to develop carriers for the delivery of PSs. Herein, a novel design is described of highly biocompatible, fluorescent, folic acid (FA)‐functionalized carbon nanodots (CDs) as carriers for the PS zinc phthalocyanine (ZnPc) to achieve simultaneous biological imaging and targeted photodynamic therapy. FA

We prepared durable, uniform, large-area ultrathin transparent films composed of double layers of reduced graphene oxide (RG-O) and multiwalled carbon nanotubes (MWNTs) via a self-assembly process. The adsorption of MWNTs onto RG-O films considerably decreased the sheet resistance of the films without compromising much on transparency. This self-assembly approach could be used to fabricate transparent electronic devices without post-transfer processes on a large scale.

A large-scale, cost-effective, and environmentally friendly synthetic strategy for biocompatible reduced graphene oxide (RGO) by using dextran as a reducing and stabilization agent has been developed. Dextran-coated RGO (D-RGO) was readily soluble in water with high biocompatibility.

Matrix-assisted laser desorption/ionization mass spectrometry has been considered an important tool for various biochemical analyses and proteomics research. Although addition of conventional matrix efficiently supports laser desorption/ionization of analytes with minimal fragmentation, it often results in high background interference and misinterpretation of the spatial distribution of biomolecules especially in low-mass regions. Here, we show design, systematic characterization, and applicatio

Among various nanoparticles, mesoporous silica nanoparticles (MSNs) have attracted extensive attention for developing efficient drug-delivery systems, mostly due to their high porosity and biocompatibility. However, due to the small pore size, generally below 5 nm in diameter, potential drugs that are loaded into the pore have been limited to small molecules. Herein, a small interfering RNA (siRNA) delivery strategy based on MSNs possessing pores with an average diameter of 23 nm is presented. T

Weighing in: Multiple kinases can be assayed simultaneously by using a method that combines peptide chips and MALDI-TOF mass spectrometry (MS). The method uses self-assembled monolayers that present a set of peptides that are each selective for a kinase. The kinase phosphorylates the peptide, changing its mass. MS analysis of the surface resolves each peptide and gives the activity of each kinase.

The paper reports a facile one-pot synthesis of core@shell nanoparticles (NPs) composed of Au core and graphene oxide nanocolloid (GON) shell. Unique properties of Au NPs and GON can be incorporated into a single nanohybrid structure to provide desirable functions for theranosis such as localized surface plasmon resonance, Raman scattering, amphiphilic surface, and photothermal conversion. Synthesis of Au@GON NPs is achieved by simple one-pot reaction in aqueous phase utilizing GON as a reducing

Long gold rods were directly grown on a reduced graphene oxide (RGO) surface by seed-mediated and seedless approaches for the fabrication of a novel Raman scattering platform. The Raman scattering signal from RGO was significantly enhanced by 34-fold at the tip of the grown gold rod.

A new method for quantitative phospholipase activity assays using mass spectrometry (MS) and a supported thin film consisting of a graphene oxide (GO)/carbon nanotube (CNT) double layer as a substrate for laser desorption ionization (LDI) has been developed. Phospholipids were very efficiently analyzed by LDI-time-of-flight (TOF) MS on the GO/CNT films, presumably because of the affinity of phospholipids for the GO/CNT surface. Therefore, the rate of lipid hydrolysis was conveniently measured us