In addition, the customized electronic board developed in this work allows several in situ operations: (1) the nanogap fabrication from photolithographed gold probes, (2) the ZnO single wire alignment among the nanogap though dielectrophoresis, and (3) the ZnO-metal LY2874455 in vitro junction electrical testing as such and under pH variation. The main goal of this work is therefore to prepare and test a nanoscale device,
correlating the strong relationship between this website the surface chemistry of the functionalized ZnO material and the ZnO-gold electrical conductance. Figure 1 The chemical structure of the amine shell on the ZnO wires. The pH-responsive structure is attributed to the reversible protonation mechanism of the amine groups. Methods Synthetic procedures The ZnO microwires were synthesized, modifying a previous synthesis , by slowly dropping 1.48 g zinc nitrate hexahydrate Zn(NO3)2?·?6H2O (5 mmol, Sigma-Aldrich S.r.l. Milan, Italy) in 10 mL bidistilled water (Direct Q, Millipore Co., Billerica, MA, USA) into 3.35 g potassium hydroxide (60 mmol, Merck KGaA, Darmstadt, Germany) in 10 mL water under vigorous stirring. The transparent solution was then transferred in a closed Teflon vessel and placed in an oven at 70°C for 5 GF120918 mouse h. Afterwards, the formed ZnO microwires were collected by filtration, washed thoroughly with water until
neutral pH was reached, and dried in air at 60°C. Post-grafting with aminopropyl groups on the ZnO microwires was carried out with 10 mol% of the functional moiety with respect to ZnO molar
amount. In detail, 250 mg (3.075 mmol) of ZnO microwire was outgassed for 2 h in a round flask connected to a Schlenk line. Then, the atmosphere was changed to nitrogen, 10 mL of dry toluene and 0.307 mmol of aminopropyltrimethoxysilane (APTMS; 55.04 mg) were added, and the solution was refluxed for 24 h under nitrogen. The functionalized microwires (ZnO-NH2) were washed with acetone and isopropanol and many then dried at 60°C overnight (Figure 1, left). Characterization Morphological and structural characterizations were carried out by field emission scanning electron microscopy (FESEM; Dual Beam Auriga from Carl Zeiss AG, Oberkochen, Germany) and by X-ray diffraction patterns with an X’Pert diffractogram (CuKα?=?1.54 Å) in Bragg-Brentano configuration. Fourier transmission infrared (FTIR) spectroscopy was carried out in attenuated total reflectance (ATR) on a Bruker Equinox 55 (spectra are baseline substracted; Bruker Optics Inc., MA, USA). Nitrogen sorption measurements were obtained at 77 K from Quadrasorb instrument (Quantachrome Instruments, Boynton Beach, FL, USA). The Brunauer-Emmett-Teller (BET) surface area was measured by multipoint method within the relative pressure range of 0.1 to 0.3 p/p0.