DNA sensors, electrochemical

The electrochemical DNA sensor shows impressive sensitivity and selectivity. The detection limit, estimated to be 5 pM, is competitive with previously reported HCMV DNA hybridization assays based on an enzyme label.52 Introduction of a noncomplementary DNA sequence (human ETS2 DNA gene) records an electrochemical signal consistent with background noise. The electrochemical DNA sensor is therefore selective for the HCMV DNA sequence. 

Screen-printed electrochemical DNA sensors for identification of microorganisms... 

The applications (Screen-printed electrochemical sensors for the detection of AChE inhibitor, Screen-printed electrochemical DNA sensors for identification of microorganisms, and Screen-printed electrochemical immunosensors for the detection of toxins) have been finalized to... 

E. Dominguez, O. Rincon and A. Narvaez, Electrochemical DNA sensors based on enzyme dendritic architectures an approach for enhanced sensitivity, Anal. Chem., 76 (2004) 3132-3138. 

In contrast to the amino acid, peptide, and protein conjugates, where a number of different organometallic complexes were used for labeling, DNA derivatives are by and large limited to ferrocene. This is very likely due to the attractive electrochemical properties of ferrocene. Indeed, electrochemical DNA sensors are covered in more detail in Section 1.31.5.2. Two recent reviews cover the ferrocene conjugates with nucleobases, nucleosides and nucleotides,... 

Ferrocenylated ODNs were first immobilized in a self-assembled redox-active monolayer on Au electrodes by Letsinger and co-workers.Upon hybridization of a complementary strand, the electrochemical potential of the ferrocene changes. In addition to applications as electrochemical DNA sensors, such self-assembled DNA monolayers with electro-active groups may provide information on the mechanism of electron transfer through DNA, and indirectly also on molecular mobility within short stretches of DNA. " We have recently extended this idea by the use of immobilized metallocene-labeled PNA on Au electrodes. Because PNA is an uncharged molecule, a surface with improved properties forms, and electrochemical detection, also of single mismatches, is facilitated. 

Figure 13.18 Schematic illustration of the electrochemical DNA sensor construction process. Reprinted with permission from Biosensors and Bioelectronics, VoL 51, p. 201-207, 2014. Permission awaited from Copyright 2014, Elsevier [172].

Sawada K, Oda C, Takao H, Ishida M (2007) Smart microfluidic electrochemical DNA sensors with signal processing circuits. Jpn J App Phys 46 3135-3138... 

With both single- and double-surface techniques detection of single-base mismatches (point mutations) is possible. At present principles of the electrochemical detection of the DNA hybridization event and determination of various genomic nucleotide sequences, after the PCR amplification of DNA, are known. On the other hand, a lot of work has to be done to develop and optimize inexpensive and simple electrochemical DNA sensors with performance comparable to that of DNA arrays based on optical detection. Determination of nucleotide sequences without DNA amplification represents a great challenge. To reach this goal it will be necessary to... 

Talanta (2002) Special issue on Electrochemistry of nucleic acids and development of electrochemical DNA sensors , vol. 56 805-976. 

Electrochemical DNA sensors and sensor arrays are being developed by at least three companies in the United States. Clinical Microsensors, Inc. (Pasadena CA) is... 

Yang, W. Gerasimov, J. Y. Lai, R. Y. Folding-based electrochemical DNA sensor fabricated on a gold-plated screen-printed carbon electrode. Chem. Commun. 2009, 20, 2902-2904. 

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