• Title/Summary/Keyword: Chemical Detection

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Avidin Induced Silver Aggregation for SERS-based Bioassay

  • Sa, Youngjo;Chen, Lei;Jung, Young Mee
    • Bulletin of the Korean Chemical Society
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    • 제33권11호
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    • pp.3681-3685
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    • 2012
  • We developed a simple and effective method for the SERS-based detection of protein-small molecule complexes and label-free proteins using avidin-induced silver aggregation. Upon excitation with light of the appropriate wavelength (633 and 532 nm), the aggregated silver nanoparticles generate a strong electric field that couples with the resonance of the molecules (atto610 and cytochrome c), increasing the characteristic signals of these molecules and resulting in sensitive detection. The detection limit of biotin with the proposed method is as low as 48 ng/mL. The most important aspect of this method is the induction of silver aggregation by a protein (avidin), which makes the silver more biocompatible. This technique is very useful for the detection of protein-small molecule complexes.

Optimization of Wave Forms for Pulsed Amperometric Detection of Cyanide and Sulfide with Silver-Working Electrode

  • 박성우;홍성욱;유재훈
    • Bulletin of the Korean Chemical Society
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    • 제17권2호
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    • pp.143-146
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    • 1996
  • A continuous potential pulse is applied to a silver-working electrode on a pulsed amperometric detector (PAD) for detection of free cyanide and sulfide. The moving phase is 0.1 M sodium hydroxide, 0.5 M sodium acetate and 5% (v/v) ethylenediamine mixture, and the flow rate is 0.7 mL/min. Optimized pulse conditions include a -200 mV (vs. Ag/AgCl reference electrode) detection potential(Ed) for 60 msec and 50 mV cleaning potential (Ec) for 120 msec. The silver working electrode surface is not poisoned by cyanide or sulfide, and the PAD maintains long-term stability without loss of sensitivity and reproducibility at these pulse conditions. The detection limit of cyanide and sulfide separated by ion chromatography using an anion exchange column is 0.1 ppm and 0.05 ppm, respectively.

Synthesis of Platinum-Reduced Graphene Oxide (Pt-rGO) Nanocomposite for Selective Detection of Hydrogen Peroxide as a Peroxidase-Mimic Catalyst

  • Doyun Park;Min Young Cho;Kuan Soo Shin
    • 대한화학회지
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    • 제67권6호
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    • pp.415-419
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    • 2023
  • In this study, we report the one-pot synthesis of reduced graphene oxide (rGO) containing platinum nanoparticles with catalytic activity to break down hydrogen peroxide as a peroxidase-mimicking catalyst. A single reducing agent was used to reduce graphene oxide and a platinum precursor at a moderately low temperature of 70℃. The rGO was homogeneously decorated with platinum nanoparticles. The catalytic activity of Pt-rGO was investigated for the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB), a peroxidase substrate, in the presence of hydrogen peroxide. The Pt-rGO coupled with glucose oxidase was also able to detect glucose at millimolar concentrations (up to 1 mM). Our results show that the Pt-rGO composite is a promising catalyst for the detection of hydrogen peroxide. This method was also applied for the detection of glucose.

지표면 화학작용제 비접촉 탐지를 위한 단자외선 라만분광법 연구 (Deep UV Raman Spectroscopic Study for the Standoff Detection of Chemical Warfare Agents from the Agent-Contaminated Ground Surface)

  • 최선경;정영수;이재환;하연철
    • 한국군사과학기술학회지
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    • 제18권5호
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    • pp.612-620
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    • 2015
  • Short-range detection of chemical agents deposited on ground surface using a standoff Raman system employing a pulsed laser at 248 nm is described. Mounted in a vehicle such as an NBC reconnaissance vehicle, the system is protected against toxic chemicals. As most chemicals including chemical warfare agents have unique Raman spectra, the spectra can be used for detecting toxic chemicals contaminated on the ground. This article describes the design of the Raman spectroscopic system and its performance on several chemicals contaminated on asphalt, concrete, sand, etc.

Advances in Rapid Detection Methods for Foodborne Pathogens

  • Zhao, Xihong;Lin, Chii-Wann;Wang, Jun;Oh, Deog Hwan
    • Journal of Microbiology and Biotechnology
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    • 제24권3호
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    • pp.297-312
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    • 2014
  • Food safety is increasingly becoming an important public health issue, as foodborne diseases present a widespread and growing public health problem in both developed and developing countries. The rapid and precise monitoring and detection of foodborne pathogens are some of the most effective ways to control and prevent human foodborne infections. Traditional microbiological detection and identification methods for foodborne pathogens are well known to be time consuming and laborious as they are increasingly being perceived as insufficient to meet the demands of rapid food testing. Recently, various kinds of rapid detection, identification, and monitoring methods have been developed for foodborne pathogens, including nucleic-acid-based methods, immunological methods, and biosensor-based methods, etc. This article reviews the principles, characteristics, and applications of recent rapid detection methods for foodborne pathogens.

주변 사업장의 화학물질 확산 감지와 대응을 위한 경계면의 센서배치 최적화 및 강건성 분석 (Optimal Sensor Placement of Boundaries and Robustness Analysis for Chemical Release Detection and Response of Near Plant)

  • 조재훈;김현승;김태옥;신동일
    • 한국가스학회지
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    • 제20권5호
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    • pp.104-111
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    • 2016
  • 최근 화학물질을 사용하는 시설이 증가하면서 동시에 시설의 노후화, 기계적 결함, 인적오류 등으로 화학물질 누출사고 피해가 많아지고 있다. 특히, 산업단지는 군집 특성으로 인해 화학물질 누출사고 발생 시 인근 사업장으로 확산되어 큰 피해로 이어질 가능성이 크다. 이에 따라 화학물질을 취급하는 공정의 누출조건, 환경조건을 반영한 다양한 누출 시나리오를 토대로 빠른 감지와 대응을 위해 경계면의 센서배치 방안을 제시할 필요가 있다. 따라서 본 연구에서는 염소가스가 누출되는 경우에 대해 COMSOL를 사용하여 주요 매개변수의 적용으로 실질적인 사고 시나리오를 해석하였다. 그리고 사고 시나리오를 바탕으로, 센서의 감지 확률과 감지시간 등 각 항목마다 중요도를 부여하여 최적 위치가 산출되도록 목적함수를 선정하였다. 또한 예상치 못한 지역의 누출사고에 대해 최적화된 센서배치의 강건성 분석을 통해 본 방안의 타당성을 높였다. 결과적으로, 기존 방식보다 효과적으로 경계면의 센서배치 최적화 방법의 적용 가능성을 확인하였다. 이상의 결과로 부터 이동식 센서의 배치방법과 농도 데이터를 기반으로, 누출원의 역추적에 도움을 줄 수 있을 것으로 기대한다.

General Survey of Detection Methods for Irradiated Foods

  • Yang, Jae-Seung
    • Nuclear Engineering and Technology
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    • 제29권6호
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    • pp.500-507
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    • 1997
  • The development of detection techniques is needed, in order for regulating authorities to determine whether or not a particular food sample has been irradiated, and label it accordingly so that a consumer's free choice can be exercised. The chemical and physical changes brought about in foods by practical doses of irradiation are very small, and therefore very sensitive methods are required. A number of promising approaches have been developed and evaluated. These include chemical, physical and biological methods ranging from the very simple to highly sophisticated techniques.

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