• Title/Summary/Keyword: Electron transfer mediator

Search Result 33, Processing Time 0.017 seconds

Concurrent Electrocatalysis and Sensing of Hydrazine and Sulfite and Nitrite Ions using Electrodeposited Gold Nanostructure-Modified Electrode

  • Seo, Yeji;Manivannan, Shanmugam;Kang, Inhak;Shin, Woo-Seung;Kim, Kyuwon
    • Journal of Electrochemical Science and Technology
    • /
    • v.8 no.1
    • /
    • pp.25-34
    • /
    • 2017
  • Concurrent electrocatalysis and sensing of hydrazine, sulfite ions, and nitrite ions in a mixture were studied using electrodes modified by electrodeposited Au nanostructures (NSs). The ${\beta}$-cyclodextrin-mixed silicate sol-gel composite was drop-casted on the electrode surface and nucleation guided by ${\beta}$-cyclodextrin occurred, followed by the electrodeposition of Au NSs. The additive, ${\beta}$-cyclodextrin, played an evident role as a structure-directing agent; thus, small raspberry-like Au NSs were obtained. The modified electrodes were characterized by surface characterization techniques and electrochemical methods. The Au NSs-modified electrodes effciently electrocatalyzed the oxidation of toxic molecules such as hydrazine and sulfite and nitrite ions even in the absence of any other electron transfer mediator or enzyme immobilization. Well-resolved oxidation peaks along with decreased overpotentials were noticed during the electrooxidation process. The fabricated Au nanostructured electrode clearly distinguished the electrooxidation peaks of each of the three analytes from their mixture.

Targeted Protein Expression in Freshly Isolated Vascular Tissues by Using Adenoviral Vector (생체에서 분리된 혈관조직에서 아데노바이러스벡터를 이용한 특정 단백질의 발현)

  • Huh, Yang Hoon;Kim, Hak Rim
    • YAKHAK HOEJI
    • /
    • v.57 no.4
    • /
    • pp.265-271
    • /
    • 2013
  • Treatments of vascular disease via modulating the expression of specific proteins by gene transfer have been attempted in various studies over the past few years. Among several methods to deliver genes, adenovirus currently has been used because of a number of positive aspects. In this study, we test adenoviral vector as a potential mediator in the treatment of vascular disease by using freshly isolated vascular tissues not cultured vascular cells. Freshly isolated vascular tissues were directly exposed to adenoviral vector pAd5CMVmcsIRESeGFPpA to check the possibility of GFP expression in different layer of vascular tissues. We found that the GFP expression by using adenoviral vector experiments is mainly focused on the adventitia and failed to detect GFP expression at endothelial layer or vascular smooth muscle layer in vascular tissues. However, we also found that several integrin receptors are robustly expressed in vascular smooth muscle, thus the limited expression of protein in vascular smooth muscle are not likely the lack of integrin receptors. In conclusion, adenovirus could not be a good tool for a specific protein expression in vascular smooth muscle cell. Thus, the application of adenovirus as a tool for gene therapy of vascular smooth muscle cells in clinical therapeutic trial need to be optimized further.

Disposable Type Electrochemical Ethanol Sensor (일회용 전기화학적 에탄올 센서)

  • Kim, Moon Hwan;Yoo, Jae Hyun;Oh, Hyun Joon;Cha, Geun Sig;Nam, Hakhyun;Park, Sung Woo;Kim, Young Man
    • Analytical Science and Technology
    • /
    • v.12 no.3
    • /
    • pp.218-223
    • /
    • 1999
  • A single use, screen-printed sensor for the measurement of liquid phase ethanol was developed and its electrochemical performance was investigated. Disposable type edthanol sensor was fabricated by serially screen printing the carbon paste, silverd pasted and insulator inlon a polyester substrate to pattern working and reference electrode sites and electrical contact. Alcohol dehydrogenase(ADH) or alcohol oxidase(AOD) together with appropriate electron transfer mediators was immobilized on the working electrode. To improve the sensitivity and reproducibility of carbon paste electrode, some pretreatment procedures were applied and their resultant electrochemical performance was examined. The disposable type electrochemical ethanol sensor developed in this study conveniently determines the ethanol in liquid samples such as blood and in fermentation process.

  • PDF