• Bulletin of the Korean Chemical Society
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• 제18권3호
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• pp.316-318
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• 1997

A general and universal detection method, which can be used in high performance liquid chromatography (HPLC) and flow injection analysis (FIA) system for the determination of any metal ions complexing with ethylenediaminetetraacetic acid (EDTA), is demonstrated. Pulsed amperometric detection scheme is applied in a flow-through thin layer electrochemical cell at an Au working electrode. Fluctuation of peak current level at the same flow rate of carrier solution is minimized at this solid working electrode, whereas not at a dropping mercury electrode. Removal of dissolved oxygen can be omitted with this detection method, which is a required step for cathodic detection methods. Also, a group of metal ions can be determined selectively and indirectly with this detection scheme.

• 한국식품과학회지
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• 제44권2호
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• pp.141-147
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• 2012

BA은 치즈, 와인, 젓갈, 소시지, 된장 등 미생물에 의한 발효과정을 거치는 식품뿐만 아니라 채소류, 과일, 육류와 같은 비발효 식품군에서도 발견된다. 식품 내 BA 오염에 대한 관리를 목적으로 제조공정 및 유통과정에서 신속하게 다량의 시료를 분석하고 제품에 대한 항시 모니터링 기술이 요구된다. 이를 위해 BA 특이항체 및 BA 분해효소를 이용하는 BA 검출 및 센싱 기술이 개발되고 있다. HisN 특이 항체를 이용한 ELISA 키트는 상용화 되었으며 다양한 식품에 적용되고 있다. 산화적 탈아미노반응을 촉매하는 아민산화효소는 항체기반의 ELISA 방식에 비해 다양한 BA 분석에 사용되고 있으며, 효소반응에 의해 생성되는 $H_2O_2$의 산화환원반응에 의해 발생하는 전류를 측정함으로써 BA의 함량을 정량할 수 있는 전류측정식 바이오센서 개발에 적용되고 있다. BA 신속검출을 위한 바이오센서의 개발 연구 동향에 발맞추어 국내 전통발효식품에 적합한 기술개발이 요구되며, 산업현장 적용 연구를 거쳐 국내 전통발효식품의 안전성을 확보해야 할 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제15권12호
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• pp.1038-1042
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• 1994

The amperometric responses of thiourea were studied in 0.1 M NaOH by flow injection analysis. D. C. amperometric and pulsed amperometric detection methods were applied for the determination of thiourea at novel metal electrodes such as Pt and Au. Triple-step potential waveforms were adopted in the pulsed amperometric detection. With an optimized pulsed waveform, the current for the oxidation of thiourea was examined with the variation of flow rate of carrier solution and with the change in the amount of sample injected. Gold working electrode turned out to be better in sensitivity and signal to noise ratio than Pt electrode in the pulsed amperometric detection of thiourea. Detection limit is estimated to be 5.33 ${\times}$ 10$^{-5}$ M with this detection method.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.595-599
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• 2013

The coordination of pyridyl-N to pentacyanoferrate for the detection of small organic antigens in solution is presented. The unique contribution of this paper is the direct conjugation of pyridyl-N in small organic antigens to pentacyanoferrate. Pentacyanoferrate is promising as an electrochemical label owing to its good electro-chemical properties, which can be utilized to generate an electrical signal in homogeneous electrochemical immunoassays. The facilely synthesized pyridyl-N to pentacyanoferrate was characterized by the electrochemical and spectroscopic methods. Hippuric acid (HA) has been detected competitively on the interaction of free HA and pentacyanoferrate-(4-aminomethylpyridine-hippuric acid) (Fe-HA) to its antibody, with the detection limit of 0.50 ${\mu}g\;mL^{-1}$. While pentacyanoferrate-based immunoassay is in its simplicity and infancy, the proposed immunoassay offers attractive opportunities for developing pyridyl-N-based the electrochemical detection of small organic antigens in the health care area.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.407.2-407.2
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• 2002

We have been studing sensitive non-enzymatic chemiluminescence (CL) imaging methods for the detection of DNA. For one of our methods, a unique chemical derivatization reagent. 3'. 4', 5'-trimethoxyphenylglyoxal (TMPG) was utilized. This reagent reacted specifically with guanine bases in nucleic acids to quickly produce a chemiluminescent derivative under mild reaction conditions. (omitted)

• Imaging Science in Dentistry
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• 제33권2호
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• pp.91-95
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• 2003

Purpose : To compare the diagnostic accuracy of proximal caries detection between Kodak Insight film and the Biomedisys CDX2000HQ digital (CCD) sensor. Materials and Methods: 156 proximal surfaces of extracted teeth, 78 of which had chemical artificial caries, were used in this study. Four observers interpreted the radiographs using a five-point confidence rating scale to record their diagnoses. The results were analyzed by receiver operating characteristic curves, ANOVA and Kappa values. Result: Analysis using receiver operating characteristic curves revealed the areas under each curve which indicated a diagnostic accuracy of 0.951 in Insight and 0.952 in CDX2000HQ digital sensor. ANOVA revealed no significant differences between the two images with respect to caries detection. Kappa values indicated that the mean intra-observer agreement was 0.85 and inter-observer agreement 0.71 in conventional radiography. In digital radiography, the mean intra-observer agreement was 0.84 and inter-observer agreement 0.72. Conclusion: The results suggest that no significant difference exists between the two modalities for artificial caries detection and that CDX2000HQ was as good as Insight film for this purpose.

• 대한화학회지
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• 제38권6호
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• pp.418-426
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• 1994

미국 환경청이 지정한 129종의 priority polluatants 중 40종의 비휘발성 염기/중성 유기화합물을 대상물질로 선정하였다. 분석방법으로 초음파 추출법(sonication extraction)과 Soxhlet 추출법(Soxhlet extraction)을 이용하여 토양에 있는 유기물을 추출 및 농축하여 기체크로마토그래프/질량분석기-SIM(selected ion monitoring)법으로 검출하였다. 표준물질이 첨가된 토양시료에 두 추출법을 적용하여 회수율을 구하고 정확도, 정밀도 및 검출한계를 측정하여 미량 분석의 가능성을 조사하였다.

• Journal of information and communication convergence engineering
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• 제17권1호
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• pp.49-59
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• 2019

Biosensors, which are analysis devices used to convert biological reactions into electric signals, are made up of a receptor component and a signal transduction part. Graphene quantum dots (GQDs) and carbon quantum dots (CQDs) are new types of carbon nanoparticles that have drawn a significant amount of attention in nanoparticle research. The unique features exhibited by GQDs and CQDs are their excellent fluorescence, biocompatibility, and low cytotoxicity. As a result of these features, carbon nanomaterials have been extensively studied in bioengineering, including biosensing and bioimaging. It is extremely important to find biomaterials that participate in biological processes. Biomaterials have been studied in the development of fluorescence-based detection methods. This review provides an overview of recent advances and new trends in the area of biosensors based on GQDs and CQDs as biosensor platforms for the detection of biomaterials using fluorescence. The sensing methods are classified based on the types of biomaterials, including nucleic acids, vitamins, amino acids, and glucose.

• Journal of Electrochemical Science and Technology
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• 제10권2호
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• pp.206-213
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• 2019

The development of simple methods for As detection has received great attention because As is a toxic chemical element causing environmental and health-related issues. In this work, the effect of nanostructures of Au electrodes on their electroanalytical performance during As detection was investigated. Different Au nanostructures with various surface morphologies such as nanoplate Au, nanospike Au, and dendritic Au structures were prepared, and their electrochemical behaviors toward square-wave anodic stripping voltammetric As detection were examined. The difference in intrinsic efficiency for As detection between nanostructured and flat Au electrodes was explained based on the crystallographic orientations of Au surfaces, as examined by the underpotential deposition of Pb. The most efficient As detection performance was obtained with nanoplate Au electrodes, and the effects of the pre-deposition time and interference on As detection of the nanoplate Au electrodes were also investigated.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.417-428
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• 2017

Diseases caused by foodborne or waterborne pathogens are emerging. Many pathogens can enter into the viable but nonculturable (VBNC) state, which is a survival strategy when exposed to harsh environmental stresses. Pathogens in the VBNC state have the ability to evade conventional microbiological detection methods, posing a significant and potential health risk. Therefore, controlling VBNC bacteria in food processing and the environment is of great importance. As the typical one of the gram-negatives, Escherichia coli (E. coli) is a widespread foodborne and waterborne pathogenic bacterium and is able to enter into a VBNC state in extreme conditions (similar to the other gram-negative bacteria), including inducing factors and resuscitation stimulus. VBNC E. coli has the ability to recover both culturability and pathogenicity, which may bring potential health risk. This review describes the concrete factors (nonthermal treatment, chemical agents, and environmental factors) that induce E. coli into the VBNC state, the condition or stimulus required for resuscitation of VBNC E. coli, and the methods for detecting VBNC E. coli. Furthermore, the mechanism of genes and proteins involved in the VBNC E. coli is also discussed in this review.