• 제목/요약/키워드: fluorescence detection

검색결과 602건 처리시간 0.027초

근적외선-II 형광 이미징을 위한 무기 나노입자 (Inorganic Nanoparticles for Near-infrared-II Fluorescence Imaging)

  • 박용일
    • 공업화학
    • /
    • 제33권1호
    • /
    • pp.17-27
    • /
    • 2022
  • 형광 이미징은 시간 분해능과 공간 해상도가 높기 때문에 기초연구에서 세포나 소동물 이미징에 널리 활용된다. 기존의 형광 이미징은 가시광선 영역의 광원을 활용하기 때문에 조직 내 광투과도가 낮고, 광원에 의한 광독성이 생길 수 있으며, 자가형광에 의한 간섭으로 검출 민감도가 떨어지는 한계가 있다. 이러한 점을 개선하기 위해 에너지가 낮은 장파장의 광원을 활용하고자 하며, 700~900 nm 영역을 활용하는 근적외선-I 형광 이미징이 개발되었고, 이미징 성능을 대폭 향상시키기 위해서 1000~1700 nm 영역의 장파장을 이용하는 근적외선-II 이미징이 연구자들의 관심을 받고 있다. 근적외선-II 영역은 광산란이 최소화되어 생체조직 내 투과도를 약 10 mm까지 향상시킬 수 있고, 생체조직의 자가형광도 최소화되어 고민감도와 고해상도의 형광 이미징이 가능하다. 본 총설에서는 다양한 근적외선-II 형광 이미징 탐침 중에서 광안정성이 뛰어나고 발광 파장 조절이 용이한 무기 나노입자 기반 탐침에 대해 살펴보았고, 그 중에서 단층 탄소 나노튜브와 양자점 및 란탄족 나노입자에 대해 중점적으로 기술하였다.

색소 농도에 따른 형광 광자의 계수율 : 광자 검출기의 dead time 효과 (Fluorescence photon counting rate as a function of dye concentration: Effect of dead time of photon detector)

  • 고동섭
    • 한국광학회지
    • /
    • 제8권4호
    • /
    • pp.353-355
    • /
    • 1997
  • 공초점 형광 현미경과 단일 광자 계수기로 구성되어 있는 단일 분자 검출장치를 사용하여, 색소 농도에 따른 광자 계수율의 변화를 관측하였다. 농도가 증가함에 따라 계수율이 포화하는 경향을 보였으며, 광검출기의 죽은 시간을 고려하여 측정 결과를 설명하였다. 계수율과 검출 부피, 광검출기의 양자효율, 입사 광량 사이의 관계를 나타내는 관계식을 제시하였다. 또한 신호대 잡음비에 대해서도 간략하게 논하였다.

  • PDF

Protein Array Fabricated by Microcontact Printing for Miniaturized Immunoassay

  • Lee Woo-Chang;Lim Sang-Soo;Choi Bum-Kyoo;Choi Jeong-Woo
    • Journal of Microbiology and Biotechnology
    • /
    • 제16권8호
    • /
    • pp.1216-1221
    • /
    • 2006
  • A protein array was fabricated for a miniaturized immunoassay using microcontact printing ($\mu$CP). A polydimethylsiloxane (PDMS) stamp with a 5 $\mu$m$\times$5 /$\mu$m dimension was molded from a silicon master developed by photolithography. Under optimal fabrication conditions, including the baking, incubation, and exposure time, a silicon master was successfully fabricated with a definite aspect ratio. An antibody fragment was utilized as the ink for the $\mu$CP, and transferred to an Au substrate because of the Au-thiol (-SH) interaction. The immobilization and antibody-antigen interaction were investigated with fluorescence microscopy. When human serum albumin (HSA) was applied to the protein array fabricated with an antibody against HSA, the detection limit was 100 pg/ml of HSA when using a secondary antibody labeled with a fluorescence tag. The fabricated protein array maintained its activity for 14 days.

Simple Pyrene Derivatives as Fluorescence Sensors for TNT and RDX in Micelles

  • Hong, Jung-Ho;Choi, Jung-Hwa;Cho, Dong-Gyu
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권11호
    • /
    • pp.3158-3162
    • /
    • 2014
  • Various pyrene derivatives were synthesized and systematically examined in micelles. Synthesized mono and bispyrene derivatives were tested in micelles so that they displayed a strong excimer band and the excimer band was quenched in the presence of TNT and RDX. In the optimized condition, the binding constant for TNT of a simple dipyrene derivative 4 was increased up to $1.0{\times}10^6M^{-1}$ in cetyl trimethylammonium bromide (CTAB) micelles, which allowed for the detection of 2 ppb of TNT and 334 ppb of RDX by fluorescence titrations.

Binding Affinities of Carbohydrate-Conjugated Chlorins for Galectin-3

  • Park, Young K.;Bold, Bayarmaa;Cui, Bing Cun;Bai, Jin Quan;Lee, Woo-Kyoung;Shim, Young-Key
    • Bulletin of the Korean Chemical Society
    • /
    • 제29권1호
    • /
    • pp.130-134
    • /
    • 2008
  • Carbohydrate-conjugated chlorins were synthesized for use as biosensors for the detection of the galectin-3 cancer marker. We used ELISA, SDS-gel electrophoresis, and Bradford assays to examine the binding of galectins to d-(+)-galactose- and b-lactose-conjugated chlorins. The binding affinities of these conjugated chlorins for galectin-3 were quantified using fluorescence spectroscopy. The fluorescence emission of the carbohydrate-conjugated chlorins decreased as the amount of galectin-3 in the binding reaction increased over a limited concentration range, indicating that carbohydrate-conjugated chlorins are potentially useful fluorescence biosensors for the galectin-3 cancer marker.

Experience with 5-Aminolevulinic Acid in Fluorescence-Guided Resection of a Deep Sylvian Meningioma

  • Chae, Michael P.;Song, Sang Woo;Park, Sung-Hye;Park, Chul-Kee
    • Journal of Korean Neurosurgical Society
    • /
    • 제52권6호
    • /
    • pp.558-560
    • /
    • 2012
  • The 5-aminolevulinic acid (5-ALA)-induced tumor fluorescence is a useful intraoperative marker for the diagnosis and the detection of various malignancies, but its use in meningioma is only reported infrequently. In meningioma, a complete resection of the tumor mass is crucial for the prevention of recurrence and postoperative morbidities. Deep sylvian meningioma is a rare type of meningioma where complete tumor removal is complicated by its deep anatomical location and close involvement with the middle cerebral artery. From our experience, 5-ALA-mediated fluorescence facilitated a safe excision whilst preserving critical neurovascular structures. To our best knowledge, this is first report from use of 5-ALA in a deep sylvian meningioma.

Fluorimetric Determination of Phosphate in Sea Water by Flow Injection Analysis

  • Motomizu, Shoji;Oshima, Mitsuko;Katsumura, Naoya
    • 분석과학
    • /
    • 제8권4호
    • /
    • pp.843-848
    • /
    • 1995
  • A sensitive method for the determination of trace amounts of phosphate by fluorescence-quenching detection / FIA is proposed. The fluorescence of Rhodamine B(RB) was quenched with the formation of the ion associate of molybdophosphate with RB;${\lambda}_{ex}$ and ${\lambda}_{em}$ were 560nm and 580nm, respectively. A calibration graph was linear over the ranges from $10^{-8}$ to $3{\times}10^{-6}M$ of phosphate (~0.3~93ppb of phosphorus). The relative standard deviation was 1.2% with $8{\times}10^{-7}M$ phosphate solution and sampling rate was 15 samples / h. The proposed method was applied to the determination of phosphate in sea and river water samples.

  • PDF

Determination of Bovine Serum Albumin by Its Enhancement Effect of Nile Blue Fluorescence

  • Lee, Sang-Hak;Suh, Jung-Kee;Li, Ming
    • Bulletin of the Korean Chemical Society
    • /
    • 제24권1호
    • /
    • pp.45-48
    • /
    • 2003
  • A novel fluorimetric method has been developed for the determination of microgram quantities of bovine serum albumin (BSA) based on its enhancement effect of Nile Blue fluorescence at 670 nm, caused by binding of Nile Blue to BSA to produce a stable water soluble complex. The binding constant of micromole Nile Blue-BSA complex was estimated by Scatchard plot method. Under the optimal conditions, the increased fluorescence intensity was linearly related to BSA concentration in the range of 0.5-12.0 ㎍/mL. The detection limit was 0.2 ㎍/mL, and the relative standard deviation of six replicate measurements was 1.4% for 10.0 ㎍/mL BSA. There was little interference from amino acids, sugars and most of metal ions.

A New Quinoline-Based Acylhydrazone for Highly Selective Fluorescence Recognition of Cu(II) and Sulfide in Aqueous Solution

  • Tang, Lijun;Zhou, Pei;Qi, Zhikai;Huang, Zhenlong;Zhao, Jia;Cai, Mingjun
    • Bulletin of the Korean Chemical Society
    • /
    • 제34권8호
    • /
    • pp.2256-2260
    • /
    • 2013
  • A new quinoline-based acylhydrazone (1) has been synthesized and applied as a fluorescent probe. Probe 1 exhibits high selectivity and sensitivity to $Cu^{2+}$ with fluorescence "ON-OFF" behavior in HEPES buffered (1‰ DMSO, HEPES 20 mM, pH = 7.4) solution. The on-site generated 1-$Cu^{2+}$ complex displays excellent selectivity to sulfide ions with fluorescence "OFF-ON" performance through copper displacement approach.

Review of Neurosurgical Fluorescence Imaging Systems for Clinical Application

  • Kim, Hong Rae;Lee, Hyun Min;Yoo, Heon;Lee, Seung Hoon;Kim, Kwang Gi
    • Journal of the Optical Society of Korea
    • /
    • 제20권2호
    • /
    • pp.305-313
    • /
    • 2016
  • A number of fluorescence imaging techniques for use in the surgical removal of glioma have been developed over the course of the long history of neurosurgery. Various biomarkers, biochemical agents, and detection systems for glioma have also been developed. This review focuses on 5-aminolevulinic acid (5-ALA), which is used to detect glioma. Numerous forms of fluorescence-guided surgery use 5-ALA, which is helpful to the surgeon. The surgical microscope system is the observational method generally used with 5-ALA, while the loupe, endoscope, and exoscope are simpler alternatives. A system is needed for minimal resection and other issues that arise during neurosurgery. Such an enhanced system should be able to detect low-grade tumors and provide information on microinvasive diseases, resulting in an improved survival rate and better surgical skills. Development of systems that fulfill certain needs would help protect the brain function of the patient and broaden the use of such systems in neurosurgery.