A capacitive DNA sensor for sensitive detection of Escherichia coli O157:H7 in potable water based on the z3276 genetic marker: fabrication and analytical performance

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

We report a label-free biosensor for the detection of Escherichia coli O157:H7 ATCC 43895 in potable water using a newly designed DNA sensing probe targeting the z3276 genetic marker.

Abstract

We report a label-free biosensor for the detection of Escherichia coli O157:H7 ATCC 43895 in potable water using a newly designed DNA sensing probe targeting the z3276 genetic marker. The surface of indium tin oxide (ITO) was functionalized with the novel sensing probe by covalent coupling using APTES as a crosslinker to fabricate the DNA sensor (dubbed ZEC [ z̲3276 gene of E̲. c̲oli O157:H7 ATCC 43895]). The electrochemical characterization of the fabricated ZEC sensor was performed using cyclic voltammetry and electrochemical impedance spectroscopy. Atomic force microscopy and scanning electron microscopy revealed significant changes in the surface topographies of the fabricated ZEC sensor chip. Equivalent circuit analyses suggested the capacitive nature of the ZEC sensor chip, which demonstrated a declining trend of the capacitance value from 1.568 μF (Bare ITO) to 1.221 μF (after DNA hybridization). Non-faradaic sensing measurements revealed systematically declining capacitance values upon DNA hybridization, with a 10 min response time at 10 Hz frequency and 10 mV applied potential. The ZEC sensor chip exhibited linearity in the range of 0.5 to 25 pg per 10 mL for E. coli O157:H7, with ubiquitous cross-validation of each DNA concentration using quantitative PCR prior to the analyses of real water samples. The limit of detection (LOD) at 95% confidence estimated by logistic regression was 0.1 pg DNA per 10 mL of E. coli O157:H7 (equivalent to 13.67 CFU per 10 mL) with a p-value of 0.0237. Consequently, the obtained results demonstrate the possible application of the developed ZEC sensor chip for E. coli O157:H7 detection in real water samples.

Related collections

Most cited references 46

Record: found
Abstract: found
Article: not found

The MIQE guidelines: minimum information for publication of quantitative real-time PCR experiments.

Stephen A. Bustin, Vladimir Benes, Jeremy A. Garson … (2009)

Currently, a lack of consensus exists on how best to perform and interpret quantitative real-time PCR (qPCR) experiments. The problem is exacerbated by a lack of sufficient experimental detail in many publications, which impedes a reader's ability to evaluate critically the quality of the results presented or to repeat the experiments. The Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines target the reliability of results to help ensure the integrity of the scientific literature, promote consistency between laboratories, and increase experimental transparency. MIQE is a set of guidelines that describe the minimum information necessary for evaluating qPCR experiments. Included is a checklist to accompany the initial submission of a manuscript to the publisher. By providing all relevant experimental conditions and assay characteristics, reviewers can assess the validity of the protocols used. Full disclosure of all reagents, sequences, and analysis methods is necessary to enable other investigators to reproduce results. MIQE details should be published either in abbreviated form or as an online supplement. Following these guidelines will encourage better experimental practice, allowing more reliable and unequivocal interpretation of qPCR results.

0 comments Cited 1835 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: not found
Article: not found

Methods for the determination of limit of detection and limit of quantitation of the analytical methods

Alankar Shrivastava, VipinB Gupta (2011)

0 comments Cited 521 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

An overview of foodborne pathogen detection: in the perspective of biosensors.

Vijayalakshmi Velusamy, Khalil Arshak, Olga Korostynska … (2010)

Food safety is a global health goal and the foodborne diseases take a major crisis on health. Therefore, detection of microbial pathogens in food is the solution to the prevention and recognition of problems related to health and safety. For this reason, a comprehensive literature survey has been carried out aiming to give an overview in the field of foodborne pathogen detection. Conventional and standard bacterial detection methods such as culture and colony counting methods, immunology-based methods and polymerase chain reaction based methods, may take up to several hours or even a few days to yield an answer. Obviously this is inadequate, and recently many researchers are focusing towards the progress of rapid methods. Although new technologies like biosensors show potential approaches, further research and development is essential before biosensors become a real and reliable choice. New bio-molecular techniques for food pathogen detection are being developed to improve the biosensor characteristics such as sensitivity and selectivity, also which is rapid, reliable, effective and suitable for in situ analysis. This paper not only offers an overview in the area of microbial pathogen detection but it also describes the conventional methods, analytical techniques and recent developments in food pathogen detection, identification and quantification, with an emphasis on biosensors. Copyright 2009 Elsevier Inc. All rights reserved.