کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6618261 | 459654 | 2012 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electrochemical detection of specific DNA and respiratory activity of Escherichia coli
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Electrochemical detection of specific DNA and respiratory activity of Escherichia coli Electrochemical detection of specific DNA and respiratory activity of Escherichia coli](/preview/png/6618261.png)
چکیده انگلیسی
We present two rapid and simplified detection methods for Escherichia coli involving the use of a hand-held potentiostat and a disposable screen-printed carbon electrode. E. coli is one of the indicator organisms used to access for food safety. Commonly, microbiological culture techniques take more than one day to yield results and therefore, a simple, cost-effective, in situ detection system is required for testing food safety. This report describes two complementary techniques for high- and low-sensitivity detection of E. coli. High-sensitivity detection relies upon quantification of DNA amplification by using polymerase chain reaction (PCR), while the simplified, low-sensitivity detection can be obtained through measurement of oxygen consumption due to respiration; importantly, both techniques utilize the same type of electrode. The former entails mixing the PCR mixture with Hoechst, an electro-active DNA intercalator, and then, measuring the oxidation current. Binding of Hoechst molecules to the amplified DNA causes the peak current to decrease because of the slow diffusion of the Hoechst-amplified DNA complex to the electrode surface. The results showed that the oxidation peak current of Hoechst decreased depending on the number of E. coli cells added to the PCR mixture as the template for amplification, and the sensitivity of the method was as low as a single bacterium. Oxygen consumption was detected by direct measurement of the cell-containing culture medium. This method required only 10 μL to be applied on the screen-printed electrode, and the reduction in oxygen current was clearly observed within 30 min when a minimum of 1 Ã 105 cells were present. These results were obtained without purifying the culture, and the samples were applied onto the electrode without any surface modifications. The techniques describes in this report are versatile, because they require the same type of electrode, have simplistic nature, use a hand-held potentiostat, and have potential to provide an in situ system for assessing food safety.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 82, 1 November 2012, Pages 132-136
Journal: Electrochimica Acta - Volume 82, 1 November 2012, Pages 132-136
نویسندگان
Keiichiro Yamanaka, Tomohiko Ikeuchi, Masato Saito, Naoki Nagatani, Eiichi Tamiya,