Electrodeposition of WO3 Nanoparticles for Sensing Applications

Santos, Lídia; Neto, Joana P.; Crespo, Ana; Baião, Pedro; Barquinha, Pedro; Pereira, Luí­s; Martins, Rodrigo; Fortunato, Elvira

doi:10.5772/61216

Cited by 18 publications

(11 citation statements)

References 69 publications

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“…Electrodeposition is a simple and reproducible technique, yet has great flexibility to produce a variety of coatings ( Ferguson et al, 2009 ). For more details about electrodeposition techniques see ( Santos et al, 2015 ). By electroplating Au or Pt, the surface roughness increases and the electrode impedance decreases ( Cui and Martin, 2003 ; Ferguson et al, 2009 ; Desai et al, 2010 ; Márton et al, 2014 ).…”

Section: Introductionmentioning

confidence: 99%

Does Impedance Matter When Recording Spikes With Polytrodes?

et al. 2018

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Extracellular microelectrodes have been widely used to measure brain activity, yet there are still basic questions about the requirements for a good extracellular microelectrode. One common source of confusion is how much an electrode’s impedance affects the amplitude of extracellular spikes and background noise. Here we quantify the effect of an electrode’s impedance on data quality in extracellular recordings, which is crucial for both the detection of spikes and their assignment to the correct neurons. This study employs commercial polytrodes containing 32 electrodes (177 μm2) arranged in a dense array. This allowed us to directly compare, side-by-side, the same extracellular signals measured by modified low impedance (∼100 kΩ) microelectrodes with unmodified high impedance (∼1 MΩ) microelectrodes. We begin with an evaluation of existing protocols to lower the impedance of the electrodes. The poly (3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT-PSS) electrodeposition protocol is a simple, stable, and reliable method for decreasing the impedance of a microelectrode up to 10-fold. We next record in vivo using polytrodes that are modified in a ‘chess board’ pattern, such that the signal of one neuron is detected by multiple coated and non-coated electrodes. The performance of the coated and non-coated electrodes is then compared on measures of background noise and amplitude of the detected action potentials. If the proper recording system is used, then the impedance of a microelectrode within the range of standard polytrodes (∼0.1 to 2 MΩ) does not greatly affect data quality and spike sorting. This study should encourage neuroscientists to stop worrying about one more unknown.

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Section: Introductionmentioning

confidence: 99%

Does Impedance Matter When Recording Spikes With Polytrodes?

et al. 2018

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“…In fact, the principal driving force for EPD is the charge and the electrophoretic mobility of the positively charged particles in the solvent under the influence of an applied electric field, where the solvent should be organic in order to avoid water electrolysis. Another type of the electrochemical deposition is the electroless (autocatalytic) deposition in the presence of a reducing agent (dissolved in the electrolyte), which acts as the electron source for the redox reaction, and no external power supply is used [23].…”

Section: Electrodeposition Methodsmentioning

confidence: 99%

Liquid-phase synthesis of nanoparticles and nanostructured materials

Karatutlu

Barhoum

Sapelkin

2018

Emerging Applications of Nanoparticles and Architecture Nanostructures

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CHAPTER 1 Liquid-phase synthesis of nanoparticles and nanostructured materials on changing their physical properties; (7) size and shape of NPs and nanostructures could be controlled quite well by the most liquid-phase synthesis methods (depending on the method used). Chemical purification and size separation techniques, such as chromatography and high-performance liquid chromatography (HPLC) are not required; (8) postsynthesis techniques are available for formation of clusters [6] and 2d superlattices [7] from the as-prepared NPs and nanostructures. The liquid-phase synthesis can be classified into: (1) top-down approaches, where bulk materials are etched in an aqueous solution for producing NPs or nanostructures, for example, the synthesis of porous silicon by electrochemical etching; and (2) bottom-up approaches, where atoms/molecules via self-assembly, in general, are gathered together to form NMs and mixed in a controlled fashion to form a colloidal solution (Fig. 1.2). NPs produced by liquid-phase synthesis methods can remain in liquid suspension for further use or may be collected by filtering or by spray drying to produce a dry powder. Liquid-phase synthesis methods from a solution of chemical compounds include, but are not limited to, chemical stain etching, colloidal methods, coprecipitation, electrochemical deposition, direct precipitation, sol-gel processing, microemulsions method, reverse micelle synthesis, hydrothermal synthesis, template methods, polyol method, and laser ablation. In this ■ ■ FIGURE 1.2 Schematic of the formation of NMs processes. Top-down versus bottom-up liquid-phase synthesis methods. ■ ■ FIGURE 1.1 Various methods for formation of NMs. The liquid-phase synthesis is reported as one of the most widespread synthesis technique together with the gas-state synthesis.

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“…Tungsten trioxide is one of the most investigated transition metal oxide materials exhibiting a wide variety of novel properties. WO3 is a n-type semiconductor material with a wide energy band gap varying from 2.6 to 3.25 eV [29,259]. nanowires produced by thermal evaporation [270]; (c) nanoflowers produced by hydrothermal method [271]; (d) microspheres produced by hydrothermal method [272].…”

Section: Tungsten Trioxidementioning

confidence: 99%

Metal oxide nanostructures for sensor applications

Nunes

Pimentel

Gonçalves

et al. 2019

Semicond. Sci. Technol.

261

119

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Human health, environmental protection and safety are just a few examples of current humankind main concerns, that drive the scientific community to develop sensors able to precisely monitor and alert to possible harms in real time. Over the years, semiconductor metal oxide-based materials have been largely employed as sensors dedicated to several applications, being particularly interesting at the nanometer scale, since it is largely known that smaller crystallite size enhances sensor's performance. Moreover, these materials are highly appealing as they can be produced by low-cost wet-chemical synthesis routes and are in general nontoxic, earth abundant and low-cost. This manuscript extensively reviews the recent developments of nanostructured semiconductor metal oxide sensors ranging from gas to humidity sensors, including ultraviolet (UV) sensors and biosensors. Zinc oxide (ZnO), titanium dioxide (TiO2), tungsten trioxide (WO3), copper oxide (CuO and Cu2O), tin oxide (SnO and SnO2), and vanadium oxide (VO2, V2O5)-based sensors either as nanoparticles or as continuous films/layers are described. Their sensing properties are correlated to size, shape, presence of defects, doping elements, amongst other relevant parameters. Different techniques and methods of fabricating these materials are addressed. The review is concluded with novel approaches for functionalization and future perspectives for sensor developments.

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Electrodeposition of WO3 Nanoparticles for Sensing Applications

Cited by 18 publications

References 69 publications

Does Impedance Matter When Recording Spikes With Polytrodes?

Does Impedance Matter When Recording Spikes With Polytrodes?

Liquid-phase synthesis of nanoparticles and nanostructured materials

Metal oxide nanostructures for sensor applications

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