홍승훈 교수

Graphene-substrate-promoted human neural stem cell adhesion and its differentiation into neurons is reported. Microarray studies were performed to explore plausible explanation for this effect. Further, an electrical stimulation on differentiated cells via graphene electrodes is demonstrated. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the au

The development of an eight-pen nanoplotter capable of doing parallel dip-pen nanolithography (DPN) is reported. Because line width and patterning speed in DPN are independent of contact force, only one of the tips in the parallel writing mode (the "imaging" tip) has a feedback system to monitor tip position and to write the pattern; all other tips reproduce what occurs at the imaging tip in a passive fashion. Proof-of-concept experiments that demonstrate eight-pen parallel writing, ink and rins

The development of reagents with high affinity and specificity to small molecules is crucial for the high-throughput detection of chemical compounds, such as toxicants or pollutants. Aptamers are short and single-stranded (ss) oligonucleotides able to recognize target molecules with high affinity. Here, we report the selection of ssDNA aptamers that bind to Bisphenol A (BPA), an environmental hormone. Using SELEX process, we isolated high affinity aptamers to BPA from a 10(15) random library of

Single-carbon-atomic-resolution detection of odorant molecules has been demonstrated using a human olfactory receptor-based bioelectric nose. Furthermore, since the human olfactory receptor is a G-protein-coupled receptor (GPCR), these sensor systems may be a new powerful platform for the development of new drugs and fragrances.

A directed-assembly method on the basis of graphene oxide (GO) pieces is developed, which allowed us to mass-produce a uniform array of graphene-based ambipolar memory devices using only conventional microfabrication facilities. Significantly, we successfully demonstrated that this device can be operated as both conventional conductivity-switching memory and new type-switching memory by adjusting the charge density on the nanoparticles.

We developed an olfactory-nanovesicle-fused carbon-nanotube-transistor biosensor (OCB) that mimics the responses of a canine nose for the sensitive and selective detection of hexanal, an indicator of the oxidation of food. OCBs allowed us to detect hexanal down to 1 fM concentration in real-time. Significantly, we demonstrated the detection of hexanal with an excellent selectivity capable of discriminating hexanal from analogous compounds such as pentanal, heptanal, and octanal. Furthermore, we

A human nose-mimetic diagnosis system that can distinguish the odor of a lung cancer biomarker, heptanal, from human blood is presented. Selective recognition of the biomarker is mimicked in the human olfactory system. A specific olfactory receptor recognizing the chemical biomarker is first selected through screening a library of human olfactory receptors (hORs). The selected hOR is expressed on the membrane of human embryonic kidney (HEK)-293 cells. Nanovesicles containing the hOR on the membr

We developed a simple but efficient method to mass-produce highly flexible and high-performance photodetectors based on aligned cadmium sulfide (CdS) nanowire (NW) networks. In this method, the CdS NWs were selectively aligned along the molecular patterns on flexible substrates via a direct assembly method, and the aligned CdS NW patterns were utilized as the channels of flexible photodetectors. The photodetectors based on the aligned CdS NWs exhibited ∼10 times higher photosensitivity and ∼100

A portable sensor platform for the detection of small molecular species is crucial for the on-site monitoring of environmental pollutants, food toxicants, and disease-related metabolites. However, it is still extremely difficult to find highly selective and sensitive sensor platforms for general small molecular detection. Herein, we report aptamer sandwich-based carbon nanotube sensor strategy for small molecular detection, where aptamers were utilized to capture target molecules as well as to e