입학 및 졸업 관련양식
연구비 및 여행관련양식
Building on Tradition
Soaring into the Future
SNU Department of Chemistry
Integrating Research and Teaching
to Advance Frontiers in Chemistry
SNU Department of Chemistry
Department of Chemistry
Seoul National University
Creative, Collaborative, and Innovative
Seoul National University
박승범 교수 연구팀 퇴행성 뇌신경 질환 치료의 새로운 작용기전을 밝혀
치매 파킨슨병과 같은 퇴행성 뇌신경 질환의 병변중의 하나인 타우단백질의 응집을 저해하는 신규 약물 후보물질을 표현형 기반 스크리닝으로 발굴 세포내 작용기작을 밝히고 동물 모델에서 효능을 확인해 퇴행성 뇌질환 치료제 개발에 실마리를 얻었다.
수소기체 얻을 수 있는 물 전기분해 촉매 개발
물 전기분해를 통한 수소생산은 수소경제를 완성하기 위해 필수적이기 때문에 중요하게 인식되고 있다. 이에 연구팀은 이차전지 양극소재인 리튬 코발트 산화물(LiCoO2)에 염화이온(Cl-)을 미세하게 도핑하는 방법으로 경제성, 효율성, 수명을 현저히 향상시킨 물 전기분해 양(+)극 촉매를 개발했다.
한국연구재단 "서울대, 생합성 모사한 비타민B3 합성법 개발"
지질대사에 필수적인 비타민 B3가 포함된 다양한 저분자 물질을 단일반응으로 얻을 수 있는 합성법이 소개됐다. 이는 다양한 생리활성 분자를 설계할 수 있는 실마리가 될 것으로 기대된다.
'껌만 씹어도 배부른 이유' 찾았다
19세기 중반부터 20세기 중반까지 생리학자들은 동물의 소화관에 구멍을 내서 물이 위에서 새어나가게 하거나 위에 풍선을 넣고 바람을 불어넣어 부풀린 뒤 먹이를 먹게 하는 실험을 진행했다.
지구온난화로 인한 이상 고온 대응 식물 생존 원리 발견
최근 이상 기온에 대응해 식물은 자체적으로 적극적인 방어 전략을 구축하고 능동적으로 적응함으로써 고온에서도 최적의 생장을 유지하고 나아가 고온에 의한 세포 피해나 식물 자체가 고사하는 상황을 효율적으로 극복하는 분자적 원리를 세계 최초로 증명했다.
장내 병원균의 감염에 필수적인 단백질의 구조 규명
서울대학교와 노트르담대학교 국제공동연구팀이 '장내 병원균 감염에 필수적인 단백질 구조'를 규명했다.
삼성 지원 연구팀, 세계 최초 DNA 컴퓨팅 인공신경망 구현
삼성이 지원한 서울대 화학부 남좌민 교수 연구팀이 DNA 컴퓨팅 아키텍처를 이용한 나노입자 인공신경망을 세계 최초로 구현했다.
고분자 단백질 스스로 형성하는 ‘자기조립’ 기술 개발
인공 효소나 생촉매, 생체물질 합성의 기반이 될 수 있는 단백질 자기조립체 합성법이 개발됐다. 송윤주 서울대 화학부 교수 연구팀은 안정적인 구조의 단백질 자기조립체를 합성할 수 있는 기술을 개발했다고 11일 밝혔다.
공지사항 / 세미나
2021 SNU 산·학·정 협력 포럼 안내
서울대학교 학생설계전공 설명회 개최 알림
2021학년도 충청남도인재육성재단 충남서부아이스쿨 멘토링활동 장학생 선발 안내
2021학년도 2학기 충청남도인재육성재단 장학생 선발 안내
특별세미나 - Prof. Dehua Pei (Charles H. Kimberly Professor, the Ohio State University)
SNU Leaders in Chemistry Colloquium (SNU LinC)
특별세미나 - Prof. Shaoyi Jiang (Cornell University)
SNU Leaders in Chemistry Colloquium (SNU LinC)
정규세미나 - 박선아 교수 (POSTECH)
Electron- and Ion-Conductive Metal Organic Frameworks
정규세미나 - 조천규 교수 (한양대학교)
RECENT PROGRESS IN THE TOTAL SYNTHESIS OF SOME INDOLE ALKALOIDS
정규세미나 - 황대희 교수 (서울대학교 생명과학부)
From Big Data to Precision Medicine
특별세미나 - 전주희 (서울대학교 화학부 정택동 교수님 연구실)
Neuroligin-1 Electrode for Specific Coupling with Pre-Synaptic Neuronal Membrane as a Robust Neural Interfacing Method
Hydrothermally obtained type-Ⅱ heterojunction nanostructures of In2S3 / TiO2 for remarkably enhanced photoelectrochemical water splitting
Despite the tremendous attempts to improve the solar-to-hydrogen conversion efficiency of TiO2 based photoelectrochemical photoanode, further progress is still needed to utilize the TiO2 as the promising photoanode materials. Herein, a highly enhanced photoanode composed of the nanostructured In2S3/TiO2 is synthesized. The photocurrent density approximately 3.5 times (2.74 mA cm−2) as high as the pristine TiO2 was obtained due to the improved carrier concentration and fast charge separation. The incident photon-to-current efficiency shows a 65.8 % while pristine TiO2 nanorods shows only 24.7 % of efficiency. Further studies on the carrier lifetime and band position were performed and clarify the generation of type-Ⅱ heterojunction between the In2S3 nanoparticles and TiO2 nanorod arrays. This study proposes the methodologies and the theoretical evidence for achieving significant improvements in the TiO2 based photoanode. Moreover, this study's all-solution-based process provides the facile and scalable method for the highly enhanced photoelectrode and allows environmentally friendly production.
3D Microfluidic Platform and Tumor Vascular Mapping for Evaluating Anti-Angiogenic RNAi-Based Nanomedicine
Three-dimensional (3D) visualization of tumor vasculature is a key factor in accurate evaluation of RNA interference (RNAi)-based antiangiogenic nanomedicine, a promising approach for cancer therapeutics. However, this remains challenging because there is not a physiologically relevant in vitro model or precise analytic methodology. To address this limitation, a strategy based on 3D microfluidic angiogenesis-on-a-chip and 3D tumor vascular mapping was developed for evaluating RNAi-based antiangiogenic nanomedicine. We developed a microfluidic model to recapitulate functional 3D angiogenic sprouting when co-cultured with various cancer cell types. This model enabled efficient and rapid assessment of antiangiogenic nanomedicine in treatment of hyper-angiogenic cancer. In addition, tissue-clearing-based whole vascular mapping of tumor xenograft allowed extraction of complex 3D morphological information in diverse quantitative parameters. Using this 3D imaging-based analysis, we observed tumor sub-regional differences in the antiangiogenic effect. Our systematic strategy can help in narrowing down the promising targets of antiangiogenic nanomedicine and then enables deep analysis of complex morphological changes in tumor vasculature, providing a powerful platform for the development of safe and effective nanomedicine for cancer therapeutics.
Highly Stable Si MOSFET-type Humidity Sensor with Ink-jet Printed Graphene Quantum Dots Sensing Layer
This paper investigates humidity sensing characteristics of a silicon metal oxide semiconductor field effect transistor (Si MOSFET)-based humidity sensor having horizontal floating-gate (FG) interdigitated with control-gate (CG). The sensing material of the humidity sensor is graphene quantum dots (GQDs), deposited locally on the interdigitated CG-FG area by an ink-jet printing method using a small amount of the GQDs solution. The humidity sensing characteristics of the sensor are measured as a parameter of relative humidity (RH). The response of the humidity sensor is 78 % to the humid air of 81.3 % RH. We also adopt a pulsed pre-bias method to improve the response and recovery characteristics of the humidity sensor. The response and recovery characteristics of the sensor can be improved 30 % and 40 % respectively by applying a pre-bias of 2 V and -1 V to the CG. In all relative humidity ranges, the FET-type humidity sensor has highly stable and reproducible characteristics in long-term measurements for 5 months.
Iridium(Ⅲ) complex-based phosphorescent and electrochemiluminescent dual sensor for selective detection of glutathione
Glutathione (GSH) is the most abundant biological thiol and involved in antioxidant defense systems in human cells. Lack of GSH increases the risk of oxidative stress, resulting in the progression of cancer. Therefore, a selective detection method for GSH is highly required. Herein, we report phosphorescent and electrochemiluminescent dual sensors (1-3) based on iridium complexes for the selective detection of GSH. These sensors have a 1,10-phenanthroline-5,6-dione (pdo) ancillary ligand as a common reaction site for GSH. Reduction of the pdo moiety to 1,10-phenanthroline-5,6-diol (phen(OH)2) upon reaction of sensors with GSH triggered fluorescence turn-on response and electrochemiluminescence turn-off response with high selectivity for GSH. Sensing mechanisms were elucidated by DFT calculations and cyclic voltammetry. Sensor 1 was successfully applied to determination of GSH concentrations in human serum samples by ECL methods.
A modeling approach to study the performance of Ni-rich layered oxide cathode for lithium-ion battery
Although there are many experimental efforts to improve the performance of lithium-ion batteries (LIBs), some interdependencies between electrode design and electrochemical performance remain unknown and warrant quantitative analysis. Herein, we present a pseudo-mesoscale finite element model developed with COMSOL Multiphysics software that describes the effect of the structural properties of the positive electrode, which is LiNi0.6Mn0.2Co0.2O2 (NMC 622), on the performance of the LIBs with lithium metal anode. The models include charge and mass conservation in the solid and electrolyte phases and the electrochemical kinetics generated at the interfaces between the solid and the electrolyte phases. Firstly, impedance plots are computed with various initial lithium contents of NMC 622, which are validated with experimental data. The validated models are then used to understand the effects of particle size and porosity of the NMC 622 cathode and varying discharge rate on the performance of the LIB. The understanding of this study can be employed to potentially predict optimized particle size and porosity for LIBs depending on the desired applications.
Rapid ignition of “green” bipropellants enlisting hypergolic copper (II) promoter-in-fuel
Ionic liquid-with-promoter fuels and H2O2 oxidizer require optimization and further exploration of inexpensive initiators that can be understood at the molecular level; it is advantageous when exacting structural characterization comparisons can also be made. For the first time, hypergolic energetic copper(II) complexes viz. [CuII(1-H-imidazole)4(BH3CN)][BH3CN] (Cu-P1) and [CuII(1-methyl imidazole)4(BH3CN)2] (Cu-P2) were developed as new ‘promoters’ for “green” space vehicle propulsion. Cu-P1 and Cu-P2 exhibited ignition delay times (IDTs) of 3.75 and 8.5 ms, respectively, with 95% H2O2. The superior solubility of Cu-P1 in ionic and non-ionic fuels helped to promote the hypergolic ignition of green liquid fuels. The ionic liquid, 1-ethyl-3-methyl imidazolium cyanoborohydride ([EMIM][BH3CN]), non-ionic tetraglyme, and mixtures thereof (1:1, wt/wt%) were employed. A 13 wt% of Cu-P1 in [EMIM][BH3CN] improved the IDT from >1000 ms to 9.50 ms with 95% H2O2 and from >5000 ms to 21.25 ms with 70% H2O2. Hence, the development of a suitable energetic promoter, soluble in ionic liquid, gained significant attention for “green” bipropellant development. Interestingly, tetraglyme is non-hypergolic with H2O2; a 13 wt% Cu-P1 induced the hypergolic ignition with an IDT of 9.0 ms (95% H2O2). Moreover, the fuel mixture of [EMIM][BH3CN] and tetraglyme (1:1, wt/wt%) with 13 wt% Cu-P1 also revealed the shortest IDT of 7.75 ms (95% H2O2) and 16.5 ms (70% H2O2). The superior ignition performance, reasonable viscosity and density, long-term stability of promoter in the fuel, and comparable theoretical performance of hypergolic propellants are advantages of our approach.
The effect of the electron-donor ability on the OLED efficiency of twisted donor-acceptor type emitters
Two twisted donor-acceptor (D-A) chemical structures, CCDMB and PCDMB, were developed as a new class of thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs). Two emitters consist of 3-substituted carbazole as a first donor and trivalent boron as an electron acceptor in common, and carbazole and phenoxazine as second donors with different electron donor ability. While PCDMB with a strong phenoxazine donor decreased the lowest singlet excited state (S1) level and thus showed a small singlet-triplet energy difference (ΔEST) value of 0.13 eV, resulting in effective reverse intersystem crossing (RISC), however, CCDMB with a weak donor showed a large ΔEST value of 0.21 eV. Efficient triplet harvesting of PCDMB was confirmed by a delayed component in transient PL decay curves of 25 wt% PCDMB-doped bis[2-(diphenylphosphino)phenyl] ether oxide (DPEPO) films. OLED devices with a CCDMB emitter showed deep-blue emission with Commission Internationale de l’Éclairage (CIE) of (0.16, 0.12) but a low maximum EQE of 5.5%, indicative of insufficient triplet harvesting. PCDMB-based devices showed green emission with CIE of (0.21, 0.45) and a high maximum EQE of 22.3%. Our study revealed the effect of the electron donor ability of structurally similar emitters on ΔEST values, triplet harvesting, and device efficiency.
Site-Specific Backbone and Side-Chain Contributions to Thermodynamic Stabilizing Forces of the WW Domain
The native structure of a protein is stabilized by a number of interactions such as main-chain hydrogen bonds and side-chain hydrophobic contacts. However, it has been challenging to determine how these interactions contribute to protein stability at single amino acid resolution. Here, we quantified site-specific thermodynamic stability at the molecular level to extend our understanding of the stabilizing forces in protein folding. We derived the free energy components of individual amino acid residues separately for the folding of the human Pin WW domain based on simulated structures. A further decomposition of the thermodynamic properties into contributions from backbone and side-chain groups enabled us to identify the critical residues in the secondary structure and hydrophobic core formation, without introducing physical modifications to the system as in site-directed mutagenesis methods. By relating the structural and thermodynamic changes upon folding for each residue, we find that the simultaneous formation of the backbone hydrogen bonds and side-chain contacts cooperatively stabilizes the folded structure. The identification of stabilizing interactions in a folding protein at atomic resolution will provide molecular insights into understanding the origin of the protein structure and into engineering a more stable protein.
Ultrahigh-strength multi-layer graphene-coated Ni film with interface-induced hardening
Graphene-reinforced metal matrix composites exhibit excellent mechanical properties owing to dislocation impedance at the metal-graphene interface. Graphene coated on metal with composites fabricated using powder sintering can be applied as high-strength thin films across various fields (e.g., microelectromechanical systems, flexible electronics). In this study, a bilayer composite of multilayer graphene (MLG)-coated Ni is synthesized using the chemical vapor deposition (CVD) and transfer methods; mechanical properties are investigated using nanoindentation methods. MLG-coated Ni synthesized by CVD exhibits 195% and 470% increases in hardness and Young’s modulus, respectively, compared with single-layer Ni. In contrast, the Young modulus and hardness of MLG-coated Ni synthesized via the transfer method can be estimated using the rule of mixture for composite materials. Transmission electron microscopy (TEM) shows that in MLG-coated Ni synthesized by CVD, dislocations are dense and evenly distributed compared with that synthesized by the transfer method, leading to its high mechanical strength. Molecular dynamics (MD) simulations demonstrate that interface-induced hardening is effective in graphene-coated Ni(111) with a strongly coupled interface. Therefore, ultrahigh-strength MLG-coated metal films can be obtained by manipulating the interface property between the MLG and metal, offering the potential for use as a thin film resistor against external force.
Human Glioblastoma Visualization: Triple Receptor-Targeting Fluorescent Complex of Dye, SIWV Tetra-Peptide, and Serum Albumin Protein
Fluorescence guided surgery (FGS) has been highlighted in the clinical site for guiding surgical procedures and providing the surgeon with a real-time visualization of the operating field. FGS is a powerful technique for precise surgery, particularly tumor resection; however, clinically approved fluorescent dyes have often shown several limitations during FGS, such as non-tumor-targeting, low in vivo stability, insufficient emission intensity, and low blood–brain barrier penetration. In this study, we disclose a fluorescent dye complex, peptide, and protein for the targeted visualization of human glioblastoma (GBM) cells and tissues. Our noble triple receptor-targeting fluorescent complex (named BSA-OXN-SIWV) consists of (i) dipolar oxazepine dye (OXN), which has high stability, low cytotoxicity, bright fluorescence, and two-photon excitable, (ii) tetra-peptide (SIWV) for the targeting of the caveolin-1 receptor, and (iii) bovine serum-albumin (BSA) protein for the targeting of albondin (gp60) and secreted protein acidic and rich in cysteine receptor. The photophysical properties and binding mode of BSA-OXN-SIWV were analyzed, and the imaging of GBM cell lines and human clinical GBM tissues were successfully demonstrated in this study. Our findings hold great promise for the application of BSA-OXN-SIWV to GBM identification and the surgery at clinical sites, as a new FGS agent.
입학 및 졸업 관련양식
연구비 및 여행관련양식