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Carbon composite micro- and nano-tubes-based electrodes for detection of nucleic acids.

Prasek J, Huska D, Jasek O, Zajickova L, Trnkova L, Adam V, Kizek R, Hubalek J - Nanoscale Res Lett (2011)

Bottom Line: MWCNTs were successfully prepared by using plasma enhanced chemical vapour deposition.Carbon composite electrode prepared from a mixture of glassy and spherical carbon powder and MWCNTs had the highest sensitivity to nucleic acids.Other interesting result is the fact that we were able to distinguish signals for all bases using this electrode.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Microelectronics, Brno University of Technology, Technicka 10, CZ-61600 Brno, Czech Republic. hubalek@feec.vutbr.cz.

ABSTRACT
The first aim of this study was to fabricate vertically aligned multiwalled carbon nanotubes (MWCNTs). MWCNTs were successfully prepared by using plasma enhanced chemical vapour deposition. Further, three carbon composite electrodes with different content of carbon particles with various shapes and sizes were prepared and tested on measuring of nucleic acids. The dependences of adenine peak height on the concentration of nucleic acid sample were measured. Carbon composite electrode prepared from a mixture of glassy and spherical carbon powder and MWCNTs had the highest sensitivity to nucleic acids. Other interesting result is the fact that we were able to distinguish signals for all bases using this electrode.

No MeSH data available.


Related in: MedlinePlus

Preparation and characterization of MWCNTs. (A) Set-up of the apparatus for PECVD MWCNTs direct deposition (according to [8]). (B) Surface-enhanced micrographs of the electrodes fabricated on the Ag-based thick film paste (1) without and (2) with use of 10 nm Fe catalyst (Tescan, Czech Republic).
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Figure 1: Preparation and characterization of MWCNTs. (A) Set-up of the apparatus for PECVD MWCNTs direct deposition (according to [8]). (B) Surface-enhanced micrographs of the electrodes fabricated on the Ag-based thick film paste (1) without and (2) with use of 10 nm Fe catalyst (Tescan, Czech Republic).

Mentions: Primarily, vertically aligned MWCNTs were prepared. A detailed drawing of the current set-up of the apparatus for plasma enhanced CVD MWCNTs direct deposition is shown in Figure 1A. The apparatus consisted of a micro-wave generator, working at a frequency of 2.45 GHz, with a standard rectangular waveguide, transmitting the micro-wave power through a coaxial line to a hollow nozzle electrode. Ferrite circulator protected the generator from the reflected power by re-routing it to the water load. The coaxial line and the nozzle electrode accommodated a dual gas flow. The central conductor of the coaxial line was held in place by boron nitride ceramics. The outer conductor was terminated by a flange. A stub tuner was mounted to the waveguide for load matching, and the reactive mixture of CH4/H2 was added by a concentric opening instead of the set of holes in the outer housing. The plasma torch was enclosed by a quartz tube, 200 mm in length, with a duralumin shielding wrapped around the tube. The diameter of the quartz tube was 80 mm. The standard deposition mixture consisted of argon (700 sccm), methane (32 sccm) and hydrogen (255 sccm). Argon passed through the centre, whereas methane/hydrogen passed through the outer housing. The substrate for MWNT growth, a piece of alumina with sensor structure, was fixed on the quartz holder at the variable distance from the torch nozzle. It was heated by a heat exchanger with hot gas and surface recombination. The deposition temperature was 700°C. The deposition was done on the pure silver layer without any catalyst and on the 10-nm-thick Fe catalyst using the same underlay. The SEM comparison of the electrode materials fabricated on the Ag thick film paste with and without use of catalyst is shown in Figure 1B. It clearly follows from the results obtained that both pastes are covered with vertically aligned MWCNTs.


Carbon composite micro- and nano-tubes-based electrodes for detection of nucleic acids.

Prasek J, Huska D, Jasek O, Zajickova L, Trnkova L, Adam V, Kizek R, Hubalek J - Nanoscale Res Lett (2011)

Preparation and characterization of MWCNTs. (A) Set-up of the apparatus for PECVD MWCNTs direct deposition (according to [8]). (B) Surface-enhanced micrographs of the electrodes fabricated on the Ag-based thick film paste (1) without and (2) with use of 10 nm Fe catalyst (Tescan, Czech Republic).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211478&req=5

Figure 1: Preparation and characterization of MWCNTs. (A) Set-up of the apparatus for PECVD MWCNTs direct deposition (according to [8]). (B) Surface-enhanced micrographs of the electrodes fabricated on the Ag-based thick film paste (1) without and (2) with use of 10 nm Fe catalyst (Tescan, Czech Republic).
Mentions: Primarily, vertically aligned MWCNTs were prepared. A detailed drawing of the current set-up of the apparatus for plasma enhanced CVD MWCNTs direct deposition is shown in Figure 1A. The apparatus consisted of a micro-wave generator, working at a frequency of 2.45 GHz, with a standard rectangular waveguide, transmitting the micro-wave power through a coaxial line to a hollow nozzle electrode. Ferrite circulator protected the generator from the reflected power by re-routing it to the water load. The coaxial line and the nozzle electrode accommodated a dual gas flow. The central conductor of the coaxial line was held in place by boron nitride ceramics. The outer conductor was terminated by a flange. A stub tuner was mounted to the waveguide for load matching, and the reactive mixture of CH4/H2 was added by a concentric opening instead of the set of holes in the outer housing. The plasma torch was enclosed by a quartz tube, 200 mm in length, with a duralumin shielding wrapped around the tube. The diameter of the quartz tube was 80 mm. The standard deposition mixture consisted of argon (700 sccm), methane (32 sccm) and hydrogen (255 sccm). Argon passed through the centre, whereas methane/hydrogen passed through the outer housing. The substrate for MWNT growth, a piece of alumina with sensor structure, was fixed on the quartz holder at the variable distance from the torch nozzle. It was heated by a heat exchanger with hot gas and surface recombination. The deposition temperature was 700°C. The deposition was done on the pure silver layer without any catalyst and on the 10-nm-thick Fe catalyst using the same underlay. The SEM comparison of the electrode materials fabricated on the Ag thick film paste with and without use of catalyst is shown in Figure 1B. It clearly follows from the results obtained that both pastes are covered with vertically aligned MWCNTs.

Bottom Line: MWCNTs were successfully prepared by using plasma enhanced chemical vapour deposition.Carbon composite electrode prepared from a mixture of glassy and spherical carbon powder and MWCNTs had the highest sensitivity to nucleic acids.Other interesting result is the fact that we were able to distinguish signals for all bases using this electrode.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Microelectronics, Brno University of Technology, Technicka 10, CZ-61600 Brno, Czech Republic. hubalek@feec.vutbr.cz.

ABSTRACT
The first aim of this study was to fabricate vertically aligned multiwalled carbon nanotubes (MWCNTs). MWCNTs were successfully prepared by using plasma enhanced chemical vapour deposition. Further, three carbon composite electrodes with different content of carbon particles with various shapes and sizes were prepared and tested on measuring of nucleic acids. The dependences of adenine peak height on the concentration of nucleic acid sample were measured. Carbon composite electrode prepared from a mixture of glassy and spherical carbon powder and MWCNTs had the highest sensitivity to nucleic acids. Other interesting result is the fact that we were able to distinguish signals for all bases using this electrode.

No MeSH data available.


Related in: MedlinePlus