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Sensitive and Reproducible Gold SERS Sensor Based on Interference Lithography and Electrophoretic Deposition

June Sik Hwang, Minyang Yang
2018 Sensors  
Surface-enhanced Raman spectroscopy (SERS) is a promising analytical tool due to its label-free detection ability and superior sensitivity, which enable the detection of single molecules. Since its sensitivity is highly dependent on localized surface plasmon resonance, various methods have been applied for electric field-enhanced metal nanostructures. Despite the intensive research on practical applications of SERS, fabricating a sensitive and reproducible SERS sensor using a simple and
more » ... process remains a challenge. Here, we report a simple strategy to produce a large-scale gold nanoparticle array based on laser interference lithography and the electrophoretic deposition of gold nanoparticles, generated through a pulsed laser ablation in liquid process. The fabricated gold nanoparticle array produced a sensitive, reproducible SERS signal, which allowed Rhodamine 6G to be detected at a concentration as low as 10-8 M, with an enhancement factor of 1.25 × 10⁵. This advantageous fabrication strategy is expected to enable practical SERS applications.
doi:10.3390/s18114076 pmid:30469441 fatcat:cxgz6pdea5c6tonsjdo4iau2xm

Laser-assisted fabrication of single-layer flexible touch sensor

Seokwoo Son, Jong Eun Park, Joohyung Lee, Minyang Yang, Bongchul Kang
2016 Scientific Reports  
Single-layer flexible touch sensor that is designed for the indium-tin-oxide (ITO)-free, bendable, durable, multi-sensible, and single layer transparent touch sensor was developed via a low-cost and one-step laser-induced fabrication technology. To this end, an entirely novel approach involving material, device structure, and even fabrication method was adopted. Conventional metal oxides based multilayer touch structure was substituted by the single layer structure composed of integrated silver
more » ... wire networks of sensors and bezel interconnections. This structure is concurrently fabricated on a glass substitutive plastic film via the laser-induced fabrication method using the low-cost organometallic/ nanoparticle hybrid complex. In addition, this study addresses practical solutions to heterochromia and interference problem with a color display unit. As a result, a practical touch sensor is successfully demonstrated through resolving the heterochromia and interference problems with color display unit. This study could provide the breakthrough for early realization of wearable device. Owing to the progress and popularization of portable devices, such as smart phones and tablet computers, the demand of touch sensors for user interfaces is dramatically increasing. From the early pressure-electric type, the touch sensor mechanisms have recently evolved to an electrostatic-capacitive type, which has many advantages such as coincident multiple sensing, high response rate, good durability, and high sensitivity, compared with other competitive methods 1 . A sensor array layer to detect a touch event and a bezel circuit to transmit the electric signal from the sensor to a drive integrated chip (IC) are the key components that directly affect the resulting engineering performance and physical properties such as transparency, resistance, size, and thickness. Indium tin oxide (ITO) is mainly used as a transparent conductive material in sensors, as it is characterized by high transparency within the visible wavelength range 2,3 . However, its application is limited to flexible, low-cost, and large area touch sensor because of its brittleness, high material cost, and relatively low conductivity 4 . In addition, the ITO-based device has some disadvantages in the fabrication process because its deposition requires expensive vacuum deposition methods, such as sputtering. Moreover, costly and complicated post-patterning processes, such as photolithography and chemical etching, are necessary. These processes should be repeated to fabricate the bezel circuit. Most previous studies attempting to resolve the issues of current touch sensors mainly focused on pioneering alternative transparent materials 5 , which can be representatively classified into four categories: conducting polymers 6 , carbon nanomaterials 7-9 , metallic one dimensional nanomaterials 10-13 , and hybrid materials 5,14,15 . These attempts do not come up with a definite answer because of the fundamental limitations represented by the limited conductivity and transparency of conducting polymers, the high junction resistance and weak adhesion of carbon nanotubes (CNT), challenging processibility of graphene, excessive haziness and low clarity of metallic nanowires, and process complexity of hybrid structures. Fundamentally, since these approaches have a conflicting relationship between conductivity and transparency, also depending on material thickness, it is considered that concurrently improving them is almost impossible 16, 17 . Metal-meshed transparent conductors, another approach adopted when using metals, consist of two dimensionally tangled metal traces of invisibly narrow width. This method provides outstanding advantages in device performance, structural simplicity, and manufacturing availability [16] [17] [18] . First, outstanding transparency and clarity are achievable without sacrificing its conductivity, since the transmittance is almost independent from a variation of structure thickness 17 . This approach supports a high design flexibility of touch sensors. Second,
doi:10.1038/srep34629 pmid:27703204 pmcid:PMC5050410 fatcat:k4lsonk2nbbl5iw5wem5ulvbi4

Solution-based adaptive parallel patterning by laser-induced local plasmonic surface defunctionalization

Bongchul Kang, Jongsu Kim, Minyang Yang
2012 Optics Express  
Adaptive mass fabrication method based on laser-induced plasmonic local surface defunctionalization was suggested to realize solution-based high resolution self-patterning on transparent substrate in parallel. After non-patterned functional monolayer was locally deactivated by laser-induced metallic plasma species, various micro/nano metal structures could be simultaneously fabricated by the parallel self-selective deposition of metal nanoparticles on a specific region. This method makes the
more » ... -friendly and cost-effective production of high resolution pattern possible. Moreover, it can respond to design change actively due to the broad controllable range and easy change of key patterning specifications such as a resolution (subwavelength~100 μm), thickness (100 nm~6 μm), type (dot and line), and shape.
doi:10.1364/oe.20.029111 pmid:23263149 fatcat:mkvawug3wfh6bjj5apfzplfiry

Heterodyne interference lithography for one-step micro/nano multiscale structuring

Bongchul Kang, Jiwhan Noh, Joohyung Lee, Minyang Yang
2013 Applied Physics Letters  
doi:10.1063/1.4841435 fatcat:3d4mti2labafjiptm72jdfasw4

Development of cost-effectiveness management tool for Korean Medicine hospitals in Korea

2015 Integrative Medicine Research  
OS03.04 Development of cost-effectiveness management tool for Korean Medicine hospitals in Korea Byungmook Lim 1 , MINYANG RHO 2 , YOONJUNG YANG 2 1 Pusan National University School of Korean Medicine  ... 
doi:10.1016/j.imr.2015.04.299 fatcat:vwotsovulff5boqmmteyysnpqi

Microelectrode fabrication by laser direct curing of tiny nanoparticle self-generated from organometallic ink

Bongchul Kang, Seunghwan Ko, Jongsu Kim, Minyang Yang
2011 Optics Express  
In this paper, we present a new laser direct patterning method that selectively cures nanoparticles self-generated from organometallic ink by proper thermal decomposition. This approach has several advantages in the curing rate, resolution and pattern quality compared with the conventional nanoparticle ink based direct laser curing method. It was found that a laser wavelength which is more weakly absorbed by the nanoparticles could produce a more stable and homogeneous curing condition.
more » ... arbitrary shaped silver electrodes with narrow width and uniform profile could be achieved on a polymer substrate at a high curing rate of 25 mm/s. This process can be applied for flexible electronics fabrications on heat sensitive polymer substrates.
doi:10.1364/oe.19.002573 pmid:21369077 fatcat:xvgpwhmqujewldt7g5yjjv6d4i

Molecular characterization of human Torque Teno virus

2015 Biomedical Reports  
The present study analyzed the presence of human Torque Teno virus (TTV) in hospitalized patients from different departments. In total, 378 serum specimens were collected from the patients (171 with cardiovascular disease, 192 with tumor and 15 with gastroenteritis) and analyzed by ELISA and nest-polymerase chain reaction (PCR) to detect the presence of TTV. The results showed that 64 specimens (17%) were TTV positive from detection with the human ELISA kit, and the patients aged <30 years have
more » ... a higher prevalence. TTV in males was more common than in female patients. In addition, nest-PCR was used to detect TTV within different phylogenetic groups among the 64 specimens, and the results showed that groups 1 (TA278 strain), 4 (KC009) and 5 (CT39) were much more prevalent than groups 2 (PMV isolate) and 3 (11 genotypes) in the different departmental patients.
doi:10.3892/br.2015.508 pmid:26623023 pmcid:PMC4660652 fatcat:ogeayb4iofdelguj47u6pydomi

Roll-to-Roll Cohesive, Coated, Flexible, High-Efficiency Polymer Light-Emitting Diodes Utilizing ITO-Free Polymer Anodes

Seongbeom Shin, Minyang Yang, L. Jay Guo, Hongseok Youn
2013 Small  
doi:10.1002/smll.201300382 pmid:23784859 fatcat:r2w34nawf5efdj2qyndpcalyve

Highly effective gold nanoparticle-enhanced biosensor array on the wettability controlled substrate by wiping

Jongsu Kim, Hyunkyu Park, Bongchul Kang, Renata Ku, Chulho Ham, Minyang Yang
2011 Journal of Applied Physics  
Nanofluidic preconcentration and detection of nanoparticles J. Appl. Phys. 112, 014304 (2012) Biofunctionalized AlGaN/GaN high electron mobility transistor for DNA hybridization detection Appl. Phys. Lett. 100, 232109 (2012) Polymer translocation under time-dependent driving forces: Resonant activation induced by attractive polymerpore interactions JCP: BioChem. Phys. 6, 05B620 (2012) Polymer translocation under time-dependent driving forces: Resonant activation induced by attractive
more » ... interactions We demonstrate the use of a highly effective biosensor array to fulfill the requirements of high intensity, reduced nonspecific adsorption (NSA), and low sample usage. The mixed self-assembled monolayers (SAMs), consisting of methyl-terminated and methoxy-(polyethylene glycol (PEG))-terminated silanes, were newly applied as the background layer to reduce the background NSA via wettability control. The surface was modified by a plasma process with a pattern mask. Gold nanoparticles (AuNPs) were grafted within pattern-modified regions to increase intensity and were modified with protein G variants with cysteine residues to immobilize the antibody proteins directly. The target protein samples were selectively dewetted by the high throughput wiping process, while retaining semi-contact with the substrate. The data revealed that the background NSA was significantly reduced by 78% with selective dewetting compared to the standard method. Furthermore, the peak intensity was improved 5 times by applying AuNPs as compared to that of a planar surface, and the protein requirement was significantly reduced versus the standard process.
doi:10.1063/1.3652860 fatcat:iq2fxa3fg5eqfia37wpf6pbc2a

Efficient Capture and Raman Analysis of Circulating Tumor Cells by Nano-Undulated AgNPs-rGO Composite SERS Substrates

Jong-Eun Park, Nuri Oh, Hyeono Nam, Ji-Ho Park, Sanha Kim, Jessie S. Jeon, Minyang Yang
2020 Sensors  
The analysis of circulating tumor cells (CTCs) in the peripheral blood of cancer patients is critical in clinical research for further investigation of tumor progression and metastasis. In this study, we present a novel surface-enhanced Raman scattering (SERS) substrate for the efficient capture and characterization of cancer cells using silver nanoparticles-reduced graphene oxide (AgNPs-rGO) composites. A pulsed laser reduction of silver nanowire-graphene oxide (AgNW-GO) mixture films induces
more » ... ot-spot formations among AgNPs and artificial biointerfaces consisting of rGOs. We also use in situ electric field-assisted fabrication methods to enhance the roughness of the SERS substrate. The AgNW-GO mixture films, well suited for the proposed process due to its inherent electrophoretic motion, is adjusted between indium tin oxide (ITO) transparent electrodes and the nano-undulated surface is generated by applying direct-current (DC) electric fields during the laser process. As a result, MCF7 breast cancer cells are efficiently captured on the AgNPs-rGO substrates, about four times higher than the AgNWs-GO films, and the captured living cells are successfully analyzed by SERS spectroscopy. Our newly designed bifunctional substrate can be applied as an effective system for the capture and characterization of CTCs.
doi:10.3390/s20185089 pmid:32906807 fatcat:htuwk3hrtrbyhdzd3z63pg27ea

Fabrication and characterization of WO3/Ag/WO3 multilayer transparent anode with solution-processed WO3 for polymer light-emitting diodes

Kangmin Jeon, Hongseok Youn, Seongbeom Kim, Seongbeom Shin, Minyang Yang
2012 Nanoscale Research Letters  
The dielectric/metal/dielectric multilayer is suitable for a transparent electrode because of its high-optical and high-electrical properties; however, it is fabricated by an expensive and inefficient multistep vacuum process. We present a WO 3 /Ag/WO 3 (WAW) multilayer transparent anode with solution-processed WO 3 for polymer light-emitting diodes (PLEDs). This WAW multilayer not only has high transmittance and low resistance but also can be easily and rapidly fabricated. We devised a novel
more » ... thod to deposit a thin WO 3 layer by a solution process in an air environment. A tungstic acid solution was prepared from an aqueous solution of Na 2 WO 4 and then converted to WO 3 nanoparticles (NPs) by a thermal treatment. Thin WO 3 NP layers form WAW multilayer with a thermal-evaporated Ag layer, and they improve the transmittance of the WAW multilayer because of its high transmittance and refractive index. Moreover, the surface of the WO 3 layer is homogeneous and flat with low roughness because of the WO 3 NP generation from the tungstic acid solution without aggregation. We performed optical simulation and experiments, and the optimized WAW multilayer had a high transmittance of 85% with a sheet resistance of 4 Ω/sq. Finally, PLEDs based on the WAW multilayer anode achieved a maximum luminance of 35,550 cd/m 2 at 8 V, and this result implies that the solution-processed WAW multilayer is appropriate for use as a transparent anode in PLEDs.
doi:10.1186/1556-276x-7-253 pmid:22587669 pmcid:PMC3467187 fatcat:d4amsxjdtvc7lkfvg75nq4zlcq

Recycling silver nanoparticle debris from laser ablation of silver nanowire in liquid media toward minimum material waste

June Sik Hwang, Jong-Eun Park, Gun Woo Kim, Hyeono Nam, Sangseok Yu, Jessie S. Jeon, Sanha Kim, Huseung Lee, Minyang Yang
2021 Scientific Reports  
AbstractAs silver nanowires (Ag NWs) are usually manufactured by chemical synthesis, a patterning process is needed to use them as functional devices. Pulsed laser ablation is a promising Ag NW patterning process because it is a simple and inexpensive procedure. However, this process has a disadvantage in that target materials are wasted owing to the subtractive nature of the process involving the removal of unnecessary materials, and large quantities of raw materials are required. In this
more » ... , we report a minimum-waste laser patterning process utilizing silver nanoparticle (Ag NP) debris obtained through laser ablation of Ag NWs in liquid media. Since the generated Ag NPs can be used for several applications, wastage of Ag NWs, which is inevitable in conventional laser patterning processes, is dramatically reduced. In addition, electrophoretic deposition of the recycled Ag NPs onto non-ablated Ag NWs allows easy fabrication of junction-enhanced Ag NWs from the deposited Ag NPs. The unique advantage of this method lies in using recycled Ag NPs as building materials, eliminating the additional cost of junction welding Ag NWs. These fabricated Ag NW substrates could be utilized as transparent heaters and stretchable TCEs, thereby validating the effectiveness of the proposed process.
doi:10.1038/s41598-021-81692-9 pmid:33500481 fatcat:nwuptpb42zhlba3trvlizvalpy

A high-quality genome assembly of Morinda officinalis, a famous native southern herb in the Lingnan region of southern China

Jihua Wang, Shiqiang Xu, Yu Mei, Shike Cai, Yan Gu, Minyang Sun, Zhan Liang, Yong Xiao, Muqing Zhang, Shaohai Yang
2021 Horticulture Research  
AbstractMorinda officinalis is a well-known medicinal and edible plant that is widely cultivated in the Lingnan region of southern China. Its dried roots (called bajitian in traditional Chinese medicine) are broadly used to treat various diseases, such as impotence and rheumatism. Here, we report a high-quality chromosome-scale genome assembly of M. officinalis using Nanopore single-molecule sequencing and Hi-C technology. The assembled genome size was 484.85 Mb with a scaffold N50 of 40.97 Mb,
more » ... and 90.77% of the assembled sequences were anchored on eleven pseudochromosomes. The genome includes 27,698 protein-coding genes, and most of the assemblies are repetitive sequences. Genome evolution analysis revealed that M. officinalis underwent core eudicot γ genome triplication events but no recent whole-genome duplication (WGD). Likewise, comparative genomic analysis showed no large-scale structural variation after species divergence between M. officinalis and Coffea canephora. Moreover, gene family analysis indicated that gene families associated with plant–pathogen interactions and sugar metabolism were significantly expanded in M. officinalis. Furthermore, we identified many candidate genes involved in the biosynthesis of major active components such as anthraquinones, iridoids and polysaccharides. In addition, we also found that the DHQS, GGPPS, TPS-Clin, TPS04, sacA, and UGDH gene families—which include the critical genes for active component biosynthesis—were expanded in M. officinalis. This study provides a valuable resource for understanding M. officinalis genome evolution and active component biosynthesis. This work will facilitate genetic improvement and molecular breeding of this commercially important plant.
doi:10.1038/s41438-021-00551-w pmid:34059651 pmcid:PMC8166937 fatcat:7kmhyzqivbgrho3qechegv4yfy

Silver Nanowire Anode-Based, Large-Area Indium Tin Oxide-Free Organic Photovoltaic Cells Fabricated by the Knife Coating Method
나이프 코팅 기법으로 제작한 은 나노와이어 투명전극 기반의 대면적 ITO-Free 유기 태양전지

Kyuhyo Han, Gunwoo Kim, Jaehak Lee, Jaeyoung Seok, Minyang Yang
2015 Journal of The Korean Society of Manufacturing Technology Engineers  
Article history: Silver nanowire (AgNW) is a material that is increasingly being used for transparent electrodes, as a substitute for indium tin oxide (ITO), owing to its flexibility, high transmittance to sheet resistance ratio, and simple production process. This study involves manufacturing large-area organic photovoltaic cells (OPVs) deposited on AgNW electrodes. We compared the efficiency of OPVs with ITO and AgNW electrodes. The results verified that an OPV with an AgNW electrode
more » ... better than that with an ITO electrode. Furthermore, by using the knife coating method, we successfully fabricated large-area OPVs without the loss of efficiency. Use of AgNW instead of ITO demonstrated that an OPV could be produced on various substrates by the solution process method, dropping the productions costs significantly. Additionally, by using the knife coating method, the process time and amount of wasted solution are reduced. This leads to an increase in the efficient fabrication of the OPV.
doi:10.7735/ksmte.2015.24.1.043 fatcat:34gryvtferh3pezojqrcbkvqgy

Indium Tin Oxide-Free Large-Area Flexible Organic Light-Emitting Diodes Utilizing Highly Conductive poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) Anode Fabricated by the Knife Coating Method
나이프 코팅 법으로 제작한 ITO-Free 고전도성 PEDOT:PSS 양극 대면적 유연 OLED 소자 제작에 관한 연구

JaeYoung Seok, Jaehak Lee, MinYang Yang
2015 Journal of The Korean Society of Manufacturing Technology Engineers  
Article history: This paper reports solution-processed, high-efficiency organic light-emitting diodes (OLEDs) fabricated by a knife coating method under ambient air conditions. In addition, indium tin oxide (ITO), traditionally used as the anode, was substituted by optimizing the conductivity enhancement treatment of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films on a polyethylene terephthalate (PET) substrate. The transmittance and sheet resistance of the optimized
more » ... PEDOT:PSS anode were 83.4% and 27.8 Ω/sq., respectively. The root mean square surface roughness of the PEDOT:PSS anode, measured by atomic force microscopy, was only 2.95 nm. The optimized OLED device showed a maximum current efficiency and maximum luminous density of 5.44 cd/A and 8,356 cd/m 2 , respectively. As a result, the OLEDs created using the PEDOT:PSS anode possessed highly comparable characteristics to those created using ITO anodes.
doi:10.7735/ksmte.2015.24.1.049 fatcat:hx45hauaifey5gcb57iz46zwii
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