Biology Reference
In-Depth Information
Chemistry (IUPAC) titled “Classification and Nomenclature of Elec-
troanalytical” Techniques” [1], “Recommended Terms, Symbols, and
DefinitionsforElectroanalyticalChemistry”[2],and“Recommended
Terms, Symbols, and Definitions for Electroanalytical Chemistry
(Recommendations 1985)” [3] and in Compendium of Analytical
Nomenclature: The Orange Book [4]. Some special articles charac-
terize electrochemical sensors [5]. A special IUPAC technical report,
“Electrochemical Biosensors: Recommended Definitions and Clas-
sification” [6], deals with techniques and terms of electrochemical
biosensors.
Since the 1990s [7] deoxyribonucleic acid (DNA) has been, and
today a rather large scale of nucleic acids (NA) is being, utilized
as the biorecognition element at a new group of biosensors-so-
called DNA or generally nucleic acid biosensors (more exactly DNA-
basedbiosensors).Veryrecently,anewtechnicalreportoftheIUPAC
under the title “Electrochemical Nucleic Acid-Based Biosensors:
Concepts, Terms and Methodology” has been prepared [8]. It
represents a critical classification of terms and techniques used in
this dynamically developing field. With respect to construction and
utilization of DNA-based biosensors, specific terminology is used
(often not uniformly) in literature. The aim of this chapter is to
present the terminology of electrochemical DNA-based biosensors
and frequently used terms in a glossary format.
The electrochemical DNA-based biosensor can be characterized
as a device that integrates DNA (generally a nucleic acid) as a
biological recognition element and an electrode as a physicochem-
ical transducer. It is often presented as an electrode chemically
modified by nucleic acid. The pioneering concept of an electrode
modified with the DNA layer has allowed a significant decrease in
the amount of DNA tested/determined [9]. Following the definition
of a chemically modified electrode [10, 11], this is true for thin
(
<
μ
m)DNAlayercoverage.Dependingonthewayofbiosensor
fabrication, thicker films of DNA occur on the electrode's surface,
whichis sometimeseven not considered and reported.
The choice of electrode material is connected, on one hand,
with the electrochemical process of interest. DNA immobilization
at the electrode surface is an initial step that plays a major
role in the overall biosensor performance. Methods used vary
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