Genosensor design

Electrode pretreatment 50 pL of 0.1 M H2SO4 are dropped on the SPCEs and an anodic current of - - 3.0 pA is applied for 2 minutes. Then, the electrodes are washed using 0.1 M Tris buffer pH 7.2. 

Adsorption of streptavidin an aliquot of 10 pL of a lx 1 M streptavidin solution is left on the electrode surface overnight at 4°C. Then, the electrode is washed with 0.1 M Tris buffer pH 7.2 to remove the excess of protein. 

Blocking step free surface sites are blocked by placing a drop of 40 pL of a 2% (w/v) solution of BSA for 15 minutes followed by a washing step with 0.1 M Tris pH 7.2 buffer containing 1% of BSA. 

Immobilization of oligonucleotide probes onto the electrode surface 40 pL of 3 -biotynilated oligonucleotide probes (0.5 ng/mL) is left on the electrode surface for 15 minutes. Finally, the electrodes are rinsed with 2 x SSC buffer pH 7.2 containing 1% of BSA. 

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Recent developments in genosensor design with the advances in nanotechnology provide new tools in order to develop new techniques to monitor biorecognition and interaction events on solid surfaces and also in solution phase. Typical applications include environmental monitoring and control, and chemical measurements in the agriculture, food, and drug industries [8-17]. 

M.I. Pividori, A. Merkoci and S. Alegret, Electrochemical genosensor design immobilisation of oligonucleotides onto transducer surfaces and detection methods, Biosens. Bioelectron., 15 (2000) 291-303. 

The genosensor design based on Av-GEB not only is able to successfully immobilize onto the electrode surface the mecA biotin-labelled capture probe, while the hybridization with the mecA target and the mecA digoxigenin-labelled probe is occurring at the same time, but also is capable of distinguishing SNPs [58,65]. 

Figure 9.14. Schematic representation of genosensor design. Reproduced with permission from Wiley InterScience [11].

In this section, a genosensor for the simultaneous detection of two of the principal causative bacteria of community acquired pneumonia is developed using a dual screen-printed sensor. The genosensor design is the same that the used in the previous section (see Fig. 9.14). 

As it has been commented, the genosensor design is the same that was used in section 9.4.3.2, with some variations... 

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