The evolution of hydrogen and oxygen was studied on diamond electrodes containing approximately 1021 boron atom/cm3. Voltammetry showed a wide potential window [−1.25 to +2.3 V vs. standard electrode (SHE)] without significant water decomposition. This much narrower for poor quality films with appreciable sp2 content. A redox couple observed at +1.7 indicates oxidation the surface prior evolution. extent increased Anodic polarization made hydrophilic; x‐ray photoelectron spectroscopy an...

Fast-scan cyclic voltammetry at high repetition rates was used to characterize adsorptive properties of dopamine (DA) native and modified carbon-fiber microelectrode surfaces. Disk electrodes were fabricated from Thornel P55 fibers, cylindrical electrodes, T650 fibers. Their surfaces by physisorption 2,6-anthraquinone disulfonic acid (2,6-AQDS) or chemisorption 4-carboxyphenyl catechols. Chemisorption accomplished via electrochemical reduction diazonium salts. The degree DA adsorption its...

The underlying cause of electrical stimulation-induced tissue trauma is debated. Our focus has been to study effects generating electrochemical by-products at the electrode–electrolyte interface, using pulse-clamp technique coupled with voltammetry analyze charge transfer. platinum–H2SO4 system a standard for analyzing electrochemistry on platinum-stimulating electrodes, even though chemical differences between H2SO4 and living body are obvious. Experiments were designed determine whether...

Objective. Neural prostheses employing platinum electrodes are often constrained by a charge/charge-density parameter known as the Shannon limit. In examining relationship between charge injection and observed tissue damage, electrochemistry at electrode-tissue interface should be considered. The charge-storage capacity (CSC) is used predictor of how much an electrode can inject during stimulation, but calculating from steady-state i-E curve (cyclic voltammogram) over water window...

Boron‐doped polycrystalline and near‐single‐crystal quality diamond electrodes were studied by voltammetry. A redox couple with vs. standard hydrogen electrode was detected on the but absent single‐crystal electrodes. The results strongly suggest that is associated reactivity at grain boundaries. Plasma fluorination of using in a radio frequency plasma eliminated +1.83 V did not alter potential range water stability. Cathodic polarization as‐grown, caused an irreversible addition oxygen to...

This paper reports the design, fabrication, and characterization of diamond-on-polymer microelectrode arrays. A "diamond-first" chemical release transfer process was implemented to integrate diamond electrodes, grown at temperatures >; 700 °C, on a temperature-sensitive polynorbornene-based (PNB) substrate, allowing for advantageous neural interfacing properties be utilized in flexible device. Intracortical probes with two electrodes peripheral nerve electrode arrays ten ranging area from...

This paper describes the application of a conducting diamond film as transparent electrode for attenuated total reflectance infrared (ATR-IR) spectroscopy during electrochemical experiments. The consists polycrystalline thin (4-6 μm) deposited on silicon wafer (∼50 μm). is pressed onto ZnSe ATR crystal with side in contact crystal; electrolyte (0.5 M film. We then electrochemically polarize and observe IR changes at diamond-electrolyte interface. Before polarization, spectra clearly show...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> An integrated circuit for wireless real-time monitoring of neurochemical activity in the nervous system is described. The chip capable conducting high-resolution amperometric measurements four settings input current. architecture includes a first-order <formula formulatype="inline"><tex Notation="TeX">$\Delta$</tex></formula> Notation="TeX">$\Sigma$</tex></formula> modulator (<formula...

Electrodes composed of boron-doped diamond (BDD) films on metal and semiconductor substrates have a wide range applications in electrochemistry. This research investigated short-lived species (SLS) produced by anodic polarization BDD electrodes 1.0 M solutions. Normal pulse voltammetry experiments were performed to identify anodically SLS with lifetimes less than 50 ms under open-circuit conditions. Potential step chronoamperometry investigate the steady-state concentrations at...

Adsorption and uptake of heavy metals by polymeric nanoparticles is driven a variety physicochemical processes. In this work, we examined metal synthetic melanin analyzed properties that affect the extent nanoparticles.Eumelanin were synthesized in one-pot fast process from 5,6-diacetoxy indole precursor hydrolyzed situ into dihydroxy (DHI). The method allows possibility changing level sodium ions ends up nanoparticles. Two variants DHI-melanin (low-sodium high variants) evaluated...

This paper reports on technology development at the sensor and circuit levels for wireless transmission of fast- scan cyclic voltammetry (FSCV) in neurochemical detection. Heavily conductive, boron-doped diamond is selectively deposited onto polished tip a tungsten microelectrode to fabricate versatile, implantable, micro-needle microprobes capable sensing brain. In addition, an integrated fabricated 0.5-mum CMOS processing electrochemical signals corresponding extracellular concentration...

Diamond electrodes are attractive for chemical and biological sensing but require high substrate temperatures vapor deposition therefore limited to temperature-tolerant substrates. Boron-doped, polycrystalline diamond electrode arrays on temperature-sensitive polymer substrates were fabricated using a "diamond-first" transfer process. This process rendered the normally inaccessible smooth nucleation surface of film as active surface. Cyclic voltammetry demonstrated basic electrochemical...

The predictions of Gibbs's law and the electrolyte theory about (negative) adsorption salts on surface aqueous salt solutions are compared with results an analysis very thin films skimmed by means a ‘film centrifuge’ from solution containing two different salts. separation effects observed mixtures CsCl/NaCl, BaCl2/ NaCl, BaCl2/CsCl, SrCl2/CsCl differ greatly theoretical results, but they agree so-called bubble process. centrifuge analytical methods briefly described.

High sensitivity, 1-10 nM detection, of biogenic amine neurotransmitters was achieved using fast-scan cyclic voltammetry at hydrogen-terminated diamond microelectrodes. This reduced to μM after 5-10 runs. To attempt understand the sensitivity decrease, electron transfer kinetics, baseline current, and rate-limiting step for high (μM) low (nM) concentrations were compared. Dopamine oxidation kinetics slowed repeated scans, ΔEp increased from 0.142 0.805 V. Baseline current decreased by 50%....

Boron-doped diamond (BDD) electrodes prepared by chemical vapor deposition were used to determine if phenol could be oxidized CO2 and biofilms "cleaned" from a surface. Cyclic voltammetry showed that electrolyzed the BDD oxidation products did not foul electrodes. Experiments also run with flow cell in which liter of 10 mM 0.1M H2SO4 was circulated through total organic carbon (TOC) monitored as function time current. The solution reduced ~1% &lt;0.1% no observable decrease decomposition...

This paper reports the development of mechanically-flexible, polycrystalline diamond-on-polymer electrodes for use as neural interfaces.Boron-doped diamond has a number properties that are attractive in recording, stimulation, and electrochemical sensing.However, because growth by chemical vapor deposition requires high temperatures (>800ºC), thin films cannot be directly deposited on polymer substrates.To address this limitation, transfer process was developed to incorporate onto...