Electrochemical Synthesis of Zinc Oxide Nanostructures on Flexible Substrate and Application as an Electrochemical Immunoglobulin-G Immunosensor

Immunoglobulin G (IgG), a type of antibody, represents approximately 75% of serum antibodies in humans, and is the most common type of antibody found in blood circulation Consequently, the development of simple, fast and reliable systems for IgG detection are of considerable interest which can be achieved using electrochemical sandwich-type immunosensors. In this study we have developed an immunosensor sub-strate using an inexpensive and very simple fabrication method based on ZnO nanorods obtained through the electrodeposition of ZnO. The ZnO nanorods were treated by electrodepositing a layer of reduced gra-phene oxide to ensure an easy immobilization of the antibodies. On this substrate, the sandwich configura-tion of the immunosensor was built through different incubation steps, that were all optimized. The im-munosensor is electrochemically active thanks to the presence of gold nanoparticles tagging the secondary antibody, therefore it has been used to measure the current density of the hydrogen development reaction which is indirectly linked to the concentration of H-IgG antigens. In this way the calibration curve was constructed obtaining a linear range of 1-100 ng / ml with a detection limit of few ng / mL and good sensi-tivity.

Study of conditions of gas- discharge synthesis of Zinc oxide nanostructures under automatic UV-irradiation of the substrate by plasma

The spectroscopic characteristics of a bipolar, overstressed discharge of nanosecond duration between zinc electrodes in oxygen at a pressure p(O2) = 13.3 kPa are presented. In the process of microexplosions of inhomogeneities on the working surfaces of the electrodes in a strong electric field, zinc vapor is introduced into the discharge gap. This creates the prerequisites for the formation of zinc oxide molecules and clusters in the plasma and the synthesis of thin island zinc oxide films, which can be deposited on a dielectric substrate installed near the center of the discharge gap. The spectral characteristics of the discharge were investigated from the central part of the discharge gap 2 mm in size. The main excited components of the plasma of a vapor-gas mixture based on zinc and oxygen were established at high values ​​of the parameter E / N (where E is the electric field strength; N is the total concentration of particles in the plasma), which, when deposited outside the discharge plasma, can lead to the formation of fine nanostructured films based on zinc oxide.

Comprehensive Overview on Zinc Oxide Nanostructures

Zinc oxide is technologically important and ZnO thin layers are widely used in sensors, transducers and catalysts designing. However, after the introduction of nanoscience and nanotechnology the gear has been shifted to its smaller counterpart in contrast to its bulk one. In this review typical synthesis procedure, growth process, classical property, and a few biological perspectives of zinc oxide nanostructures have been highlighted. In coming years new synthetic strategy, benign fabrication will be introduced with plethora of versatile and beneficial applications based on zinc oxide nanostructures.