Electrochemical interaction detection

There are a number of electrochemical interactions which may be useful as the basis for detection in HPLC the most commonly used electrochemical detectors are based on amperometric measurements. The principle of operation of an amperometric detector is the oxidation or reduction of analyte in a flow-through electrolysis cell with a constant applied electrical potential, e.g. the oxidation of hydroquinone. 

Finally, attempts have been made to perform electrochemical DNA detection without having to use metal-modified ODNs. " This can be achieved by immobilizing the capture ODN on an electrode, allowing it to hybridize with the target DNA, and then adding an electro-active compound that will interact only with ds-DNA. Quite a number of compounds have been used for detection, including Go complexes, ethidium bromide, and... 

The topics discussed in the book include electrochemical detection of DNA hybridization based on latex/gold nanoparticles and nanotubes nanomaterial-based electrochemical DNA detection electrochemical detection of microorganism-based DNA biosensor gold nanoparticle-based electrochemical DNA biosensors electrochemical detection of the aptamer-target interaction nanoparticle-induced catalysis for DNA biosensing basic terms regarding electrochemical DNA (nucleic acids) biosensors screen-printed electrodes for electrochemical DNA detection application of field-effect transistors to label-free electrical DNA biosensor arrays and electrochemical detection of nucleic acids using branched DNA amplifiers. 

The aim of this book is to cover the full scope of electrochemical nucleic acid biosensors by emphazing on DNA detection. The material is presented in 16 chapters. Starting with the terminology related to electrochemical DNA-based biosensors in Chapter 1, the researchers active in the fields of biosensor design, molecular biology, and genetics describe types of detection used for analysis (chapters 6, 9, 11, and 13), types of materials used for biosensor design (chapters 3, 4, 5, 8, 10, and 14), and types of nucleic acid interactions detected (chapters 2, 7,12, and 15). 

Fig. 13 Examples of electrochemical I detection of reversible interactions of duplex DNA with small molecules. (A), AdTS AC voltammetric behavior of dsDNA adsorbed at HMDE in the presence of chloroquine (CQ). (a), no CQ (b), 10 pM CQ (c), 50 pM CQ. Upon binding of intercalators, DNA peak 2 increases while peak 3 decreases. (B), interaction of DNA with DM dt followed by CPSA at CPE. As a result of dE DM binding to DNA, peak S...

Compared to electrochemical enzymatic detection, it can be said that affinity-based interactions help us monitor assays that are more complex (Wang, 2006). Electrochemical techniques are very proper techniques to follow the biorecognition events in affinity-based sensors. Although amperometric detection is more practical relative to EIS, especially for monitoring the changes at the electrode surface, EIS is preferred (Lafleur et al., 2016). 

Table 8.76 shows the main characteristics of voltammetry. Trace-element analysis by electrochemical methods is attractive due to the low limits of detection that can be achieved at relatively low cost. The advantage of using standard addition as a means of calibration and quantification is that matrix effects in the sample are taken into consideration. Analytical responses in voltammetry sometimes lack the predictability of techniques such as optical spectrometry, mostly because interactions at electrode/solution interfaces can be extremely complex. The role of the electrolyte and additional solutions in voltammetry are crucial. Many determinations are pH dependent, and the electrolyte can increase both the conductivity and selectivity of the solution. Voltammetry offers some advantages over atomic absorption. It allows the determination of an element under different oxidation states (e.g. Fe2+/Fe3+). 

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