• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.314-314
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• 2006

The FRET property has been extensively studied from the theoretical view points to the practical applications. In case that the donor and acceptor are confined in nanodimension, the FRET effectively occurs, because of their distant dependent characteristic. However, there are no reports concerning FRET with one dimensional (1D) nanomaterial. We have successfully prepared the PMMA nanotubes using vapor deposition polymerization as the platform of FRET. The dye-PMMA composite nanofiber has also been produced without phase separation and any deterioration of properties of the dyes. The PMMA 1D nanocomposite doped two dyes with great spectral overlap between donor and acceptor displayed FRET property.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.105-106
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• 2013

Surface plasmon resonance (SPR) is classified into the propagating surface plasmon (PSP) excited on flat metal surfaces and the local surface plasmon (LSP) excited by metalnanoparticles. It is known that fluorescence signals are enhanced by these two SPR-fields.On the other hand, fluorescence is quenched by the energy transfer to metal (FRET). Bothphenomena are controlled by the distance between dyes and metals, and the degree offluorescence enhancement is determined by the correlation. In this study, we determined thecondition to achieve the maximum fluorescence enhancement by adjusting the distance of ametal nanoparticle 2D sheet and a quantum dots 2D sheet by the use of $SiO_2$ spacer layers. The 2D sheets consisting of myristate-capped Ag nanoparticles (AgMy nanosheets) wereprepared at the air-water interface and transferred onto hydrophobized gold thin films basedon the Langmuir-Schaefer (LS) method [1]. The $SiO_2$ sputtered films with different thickness (0~100 nm) were deposited on the AgMy nanosheet as an insulator. TOPO-cappedCdSe/CdZnS/ZnS quantum dots (QDs, ${\lambda}Ex=638nm$) [2] were also transferred onto the $SiO_2$ films by the LS method. The layered structure is schematically shown in Fig. 1. The result of fluorescence measurement is shown in Fig. 2. Without the $SiO_2$ layer, the fluorescence intensity of the layered QD film was lower than that of the original QDs layer, i.e., the quenching by FRET was predominant. When the $SiO_2$ thickness was increased, the fluorescence intensity of the layered QD film was higher than that of the original QDs layer, i.e., the SPR enhancement was predominant. The fluorescence intensity was maximal at the $SiO_2$ thickness of 20 nm, particularly when the LSPR absorption wavelength (${\lambda}=480nm$) was utilized for the excitation. This plasmonic nanosheet can be integrated intogreen or bio-devices as the creation point ofenhanced LSPR field.

• Korean Chemical Engineering Research
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• 제57권6호
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• pp.898-906
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• 2019

본 연구에서는 전기천공시스템에서 형광 염료를 사용한 세포 생존율 평가와 형광 염료를 전달 물질로 하여 세포 내부로의 전달 효율 평가를 통해 세포의 생존율과 전달 물질의 전달 효율 평가에 사용하기 적합한 형광 염료의 선정 및 사용에 적절한 농도에 대한 가이드라인을 제시 할 수 있는 기초 연구를 수행하였다. 형광 염료로는 Propidium Iodide와 Yo-Pro-1을 사용하였다. Propidium Iodide과 Yo-Pro-1을 사용한 세포 생존율 평가와 전달 효율의 평가에서 각 형광염료의 유세포 분석 히스토그램의 모양은 형광 염료의 종류와 사용한 농도에 따라 다른 것을 확인하였다. 이는 사용하는 형광 염료의 특성과 연관이 있는 것으로 이 결과를 통해 세포 분석에 사용하는 형광 염료의 특성에 따라 분석 결과가 달라지는 것을 알 수 있었다. 형광 염료 자체가 세포 생존률에 미치는 영향은 크지 않음을 확인하였다. 또한 두 종류 이상의 형광 염료를 사용하여 분석을 하는 경우 발생할 수 있는 형광 신호 간의 간섭 영향을 확인하였다. 간섭의 영향은 Yo-Pro-1의 농도가 높을수록 큰 것으로 확인되었으며 Propidium Iodide의 농도는 형광 신호의 간섭에 큰 영향을 미치지 않음을 확인하였다. 본 연구를 통해 형광 염료의 종류와 농도에 따라 세포 생존율 평가와 전달 효율의 평가 결과가 영향을 받는 것을 확인했으며 이는 형광 염료의 특성과 연관이 있는 것으로 판단된다. 또한, 본 연구 결과를 토대로 세포 생존율 평가와 전달 효율 평가에 적절한 형광 염료의 선정과 사용에 적절한 농도를 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제5권6호
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• pp.253-259
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• 1984

An analytical applicability of the fluorescence detection with an optical multichannel analyzer to organic dyes was studied in this work. Continuous acquisition of spectra was possible with the use of a microcomputer. The maximum acquisition rate of a spetrum with 70-point average was about 3 seconds. Floppy discs were used to store data for later use in processing. Laser induced fluorescence detector in High Performance Liquid Chromatography was chosen for an application. Fluorescein below $10^{-15}g$ was detected satisfactorily using this system. With the help of microcomputer, three dimensional chromatograms of time-wavelength-intensity were obtained.

• 대한의용생체공학회:의공학회지
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• 제36권1호
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• pp.16-21
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• 2015

Indocyanine green(ICG) and 5-aminolevulinic acid(5-ALA) have been widely used to mark blood vessels or tumors. However, fluorescent dye detection systems were designed to use one type of dyes only. In this study, we proposed a detection system capable of detecting Indocyanine green and 5-aminolevulinic acid. Multiple filters and light sources are integrated into a single system. In this study, we performed analysis of fluorescent dyes and configured a detection system. During the analysis, it was found that Indocyanine green and 5-aminolevulinic acid have the maximum intensity at $40{\mu}M$. We designed light source for fluorescent dyes and conducted compatibility test using a commercial surgical microscope. The fluorescent dye detection system was configured based on the experimental results. The developed system successfully detects Indocyanine green and 5-aminolevulinic acid. Therefore, more efficient surgical operations can be achieved using both fluorescent dyes at the same time. We expect that the developed system can increase the survival rate of patients.

• 한국염색가공학회지
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• 제25권4호
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• pp.254-261
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• 2013

In this study, we synthesized a new fluorescent polypyridyl dye 2 containing a 2,2'-bipyridine in the center and two 2,2':6',2"-terpyridines at both ends. When exposed to various metal ions, the dye 2 showed selective fluorescence responses. In the presence of $Cu^{2+}$ and $Ni^{2+}$, it exhibited a highly effective fluorescence quenching, leading to large $K_{sv}$ values of up to $10^5$. In response to most other metal ions including $Al^{3+}$, in contrast, its fluorescence changes little, showing a small Ksv value at $10^2$. Meanwhile, the compound 2 revealed a differentiated fluorescence response to $Zn^{2+}$, which is evidenced by a large red shift of > 100 nm. Such a red shift from the ion binding is attributed to the planarization of the bipyridyl unit extending the effective conjugation length in conjunction. A polypyridyl compound will find important usefulness in chemosensor application due to its selective binding to metal ions. Subsequent research concerned with modified derivatives is currently going on, as a way to provide high solubility even after metal-complexing.

• 약학회지
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• 제41권6호
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• pp.749-755
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• 1997

It has been reported that dose-dependent $Ca^{2+}$ increase by menadione in platelets could be measured by fluorescent dye, quin-2. The problems will be described here rel ating to measuring $Ca^{2+}$ in menadione-exposed platelets using fura-2 and fluo-3, widely used fluorescent indicators. Additions of menadione to fura-2 loaded platelets and their lysates resulted in marked reduction in fluorescence intensity at both 340nm ($Ca^{2+}$-unbound form) 380nm ($Ca^{2+}$-undbound form) excitation wavelengths. Fura-2 excitation spectra were overlapped with UV-visible absorption spectra of menadione, suggesting that light absorption by menadione itself could quench fluorescence generated by fura-2. Next approach was to use fluo-3 which has the higher wavelength (490nm) of excitation. Previous work demonstrated that treatment with probenecid to platelets was required to prevent fluo-3 dye leakage. However, probenecid itself was proven to be inadequate to measure the concentration of intracellular $Ca^{2+}$; by reducing menadione-induced cytotoxicity in platelets. Our results suggest that it is not feasible to measure $Ca^{2+}$ in platelets by using fura-2 and fluo-3 in the presence of probenecid, and cautions should be taken to measure changes of intracellular $Ca^{2+}$ levels by fluorescent dyes following chemical exposure.

• Journal of Information Display
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• 제11권3호
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• pp.123-127
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• 2010

Fluorescent white organic light-emitting diodes showing high color-rendering indices (CRIs) of up to 81 was demonstrated, with a silicon-cored anthracene derivative (PATSPA) doped with DPAVBi utilized as the deep-blue host and dye materials, and the commercial dyes rubrene and DCM2 utilized as the orange- and red-light-emitting dyes. The devices, consisting of three emissive layers, showed bright-white-light emission, but the ratio of the blue peak to the orange and red peaks changed with the current density and the thickness of the blue emissive layer. A high CRI was achieved with the use of a deep-blue emitter doped in a novel host and by optimizing the blue-layer thickness. The device with a blue-layer thickness of 10 nm showed the Commission Internationale de l'Eclairage (CIE) color coordinate of (0.33, 0.35), a high CRI of 81, and a moderate external quantum efficiency of 2% at a current density of $2.5\;mA/cm^2$.

• Journal of Dairy Science and Biotechnology
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• 제33권4호
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• pp.271-275
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• 2015

Colloidal semiconductor CdSe-ZnS core-shell nanocrystal quantum dot (Qdot) are luminescent inorganic fluorophores that show potential to overcome some of the functional limitations encountered with organic dyes in fluorescence labeling applications. Salmonella Enteritidis has emerged as a major cause of human salmonellosis worldwide since the 1980s. A rapid, specific, and sensitive method for the detection of Salmonella Enteritidis was developed using Qdot as a fluorescence marker coupled with immunomagnetic separation. Magnetic beads coated with anti-Salmonella Enteritidis antibodies were employed to selectively capture the target bacteria, and biotin-conjugated anti-Salmonella antibodies were added to form sandwich immune complexes. After magnetic separation, the immune complexes were labeled with Qdot via biotin-streptavidin conjugation, and fluorescence measurement was carried out using a fluorescence measurement system. The detection limit of the Qdot method was a Salmonella Enteritidis concentration of $10^3$ colony-forming units (CFU)/mL, whereas the conventional fluorescein isothiocyanate-based method required over $10^5CFU/mL$. The total detection time was within 2 h. In addition to the potential for general nanotechnology development, these results suggest a new rapid detection method of various pathogenic bacteria from a complex food matrix.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권3호
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• pp.105-110
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• 2002

J-aggregates in the mutual mixing LB films of [6Me-DS]$_{1-x}$ [DO]$_{x}$,[DS]$_{1-x}$ [DO]$_{x}$ and [DSe]$_{1-x}$ [DO]$_{x}$ have been studied by optical absorption, fluorescence and surface pressure-area isotherms. In [6Me-DS]$_{1-x}$ [DO]$_{x}$ films, sharp J-band absorption and fluorescence of [6Me-DS] are linearly shifted to the longer wavelength for the replacement of [6Me-DS] by [DO]. According to the x, a smooth shift of the limited area has been cleared. In the [DS]-[DO] system, the J-band is enhanced at 1:1 composition and strong fluorescence is also observed. Also, the presence of phase separation was suggested in the [DSe]-[DO] system, because the absorption spectra were decomposed into [DSe] and [DO] spectra. On the other hand, in the pressure-area isothermal study, reduction in the molecular occupying area of monolayers has been clarified. This could be ascribed to the enhancement of molecular ordering in J-aggregates. These facts are also believed to reflect the most closely packed arrangement of chromophores in the merocyanine dye monolayers. Thus, it was confirmed that the interaction between mixed dye molecules and the CdC1$_2$+KHCO$_3$subphases affected the J-aggregates of the LB films. Also. it is thought that the J-aggregates are formed non-dimensionally in LB films, such as solution synthesized [DX:DO] assemblies on mixing.s on mixing.