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- Cioffi, Nicola, et al.
(författare)
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Electrosynthesis and characterization of gold nanoparticles for electronic capacitance sensing of pollutants
- 2011
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Ingår i: Electrochimica Acta. - : Elsevier Science B.V., Amsterdam.. - 0013-4686 .- 1873-3859. ; 56:10, s. 3713-3720
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, gold/surfactant core/shell colloidal nanoparticles with a controlled morphology and chemical composition have been obtained via the so-called sacrificial anode technique, carried out in galvanostatic mode. As synthesized Au-NPs had an average core diameter comprised between 4 and 8 nm, as a function of the electrochemical process experimental conditions. The UV-Vis characterization of gold nanocolloids showed clear spectroscopic size effects, affecting both the position and width of the nanoparticle surface plasmon resonance peak. The nanomaterial surface spectroscopic characterization showed the presence of two chemical states, namely nanostructured Au(0) (its abundance being higher than 90%) and Au(I). Au-NPs were then deposited on the top of a capacitive field effect sensor and subjected to a mild thermal annealing aiming at removing the excess of stabilizing surfactant molecules. Au-NP sensors were tested towards some gases found in automotive gas exhausts. The sensing device showed the largest response towards NOx, and much smaller - if any - responses towards interferent species such as NH3, H-2, CO, and hydrocarbons.
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| 2. |
- Cotrone, Serafina, et al.
(författare)
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Phospholipid film in electrolyte-gated organic field-effect transistors
- 2012
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Ingår i: Organic electronics. - : Elsevier. - 1566-1199 .- 1878-5530. ; 13:4, s. 638-644
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Tidskriftsartikel (refereegranskat)abstract
- A totally innovative electrolyte-gated field effect transistor, embedding a phospholipid film at the interface between the organic semiconductor and the gating solution, is described. The electronic properties of OFETs including a phospholipid film are studied in both pure water and in an electrolyte solution and compared to those of an OFET with the organic semiconductor directly in contact with the gating solution. In addition, to investigate the role of the lipid layers in the charge polarization process and quantify the field-effect mobility, impedance spectroscopy was employed. The results indicate that the integration of the biological film minimizes the penetration of ions into the organic semiconductor thus leading to a capacitive operational mode as opposed to an electrochemical one. The OFETs operate at low voltages with a field-effect mobility in the 10−3 cm2 V−1 s−1 range and an on/off current ratio of 103. This achievement opens perspectives to the development of FET biosensors potentially capable to operate in direct contact with physiological fluids.
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