Electrokinetic techniques applied to electrochemical DNA biosensors

Abstract

Electrokinetic techniques are contact-free methods currently used in many applications, where precise handling of biological entities, such as cells, bacteria or nucleic acids, is needed. These techniques are based on the effect of electric fields on molecules suspended in a fluid, and the corresponding induced motion, which can be tuned according to some known physical laws and observed behaviours. Increasing interest on the application of such strategies in order to improve the detection of DNA strands has appeared during the recent decades. Classical electrode-based DNA electrochemical biosensors with combined electrokinetic techniques present the advantage of being able to improve the working electrode's bioactive part during their fabrication and also the hybridization yield during the sensor detection phase. This can be achieved by selectively manipulating, driving and directing the molecules towards the electrodes increasing the speed and yield of the floating DNA strands attached to them. On the other hand, this technique can be also used in order to make biosensors reusable, or reconfigurable, by simply inverting its working principle and pulling DNA strands away from the electrodes. Finally, the combination of these techniques with nanostructures, such as nanopores or nanochannels, has recently boosted the appearance of new types of electrochemical sensors that exploit the time-varying position of DNA strands in order to continuously scan these molecules and to detect their properties. This review gives an insight into the main forces involved in DNA electrokinetics and discusses the state of the art and uses of these techniques in recent years.

Controlling DNA/Surface Interactions for Potential Pulse‐Assisted Preparation of Multi‐Probe DNA Microarrays

“…Barton's group recently published a study on DNA array formation using a bi‐potentiostat and a two‐electrode platform, where one electrode consisted of individually connectable patterned gold lines for electrochemical activation of the copper catalyst catalyzing alkyne‐azide click reaction and local grafting of DNA sequences on the other substrate electrode . Furthermore, several approaches employing electric fields to attach ssDNA to pre‐selected positions were investigated throughout the years . One such approach was comercialized by the company Nanogen, employing an electric field to immobilize biotin‐ssDNA through an polyacrylamide gel permeation layer onto specific sites modified with streptavidin …”

“…[7] Furthermore, several approaches employing electric fields to attach ssDNA to pre-selected positions were investigated throughout the years. [8][9][10] One such approach was comercialized by the company Nanogen, employing an electric field to immobilize biotin-ssDNA through an polyacrylamide gel permeation layer onto specific sites modified with streptavidin. [11][12][13] Coupling electrochemistry with AuÀ S chemistry presents another alternative for modifying microarrays.…”

Rapid detection of blaNDM-1 in multidrug-resistant organisms using a novel electrochemical biosensor

“…Unlike the detection methods described above, electrochemical biosensors have advantages such as short analysis time, device miniaturization, high specicity and sensitivity, and low limits of detection. 17,18 An electrochemical biosensor is typically composed of biological molecule recognition elements and a signal transformer. The potential difference between the electrode surface and electrolyte solution changes when the electrochemical reactions of the chemical elements in the base electrolyte solution change.…”

Self‐Powered and Sensitive DNA Detection in a Three‐Dimensional Origami‐Based Biofuel Cell Based on a Porous Pt‐Paper Cathode

“…The sequencing and detection of DNA has attracted more attention during the last 25 years due to its application in many research and technological fields that range from forensics to clinical diagnostics. [1] Sensitive detection of specific nucleic acid sequences on the basis of the hybridization reaction can be improved by target or signal amplification strategies. [2] Up to now several methods, including electrochemical, [3] optical, [4] or mass-sensitive techniques, [5] have been applied to the detection of specific DNA sequences.…”