scholarly journals Microelectrochemical Smart Needle for Real Time Minimally Invasive Oximetry

Biosensors ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 157
Author(s):  
Daniela Vieira ◽  
Francis McEachern ◽  
Romina Filippelli ◽  
Evan Dimentberg ◽  
Edward J Harvey ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Real Time ◽  
Surface Area ◽  
Electrochemical Detection ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Brain Dysfunction ◽  
The Brain

A variety of brain disorders such as neural injury, brain dysfunction, vascular malformation, and neurodegenerative diseases are associated with abnormal levels of oxygen. Current methods to directly monitor tissue oxygenation in the brain are expensive and invasive, suffering from a lack of accuracy. Electrochemical detection has been used as an invasiveness and cost-effectiveness method, minimizing pain, discomfort, and injury to the patient. In this work, we developed a minimally invasive needle-sensor with a high surface area to monitor O2 levels in the brain using acupuncture needles. The approach was to directly etch the iron from stainless steel acupuncture needles via a controlled pitting corrosion process, obtaining a high microporous surface area. In order to increase the conductivity and selectivity, we designed and applied for the first time a low-cost coating process using non-toxic chemicals to deposit high surface area carbon nanoparticle, catalytically active laccase, and biocompatible polypyrrole. The physicochemical properties of the materials were characterized as well as their efficacy and viability as probes for the electrochemical detection of PO2. Our modified needles exhibited efficient electrocatalysis and high selectivity toward O2, with excellent repeatability. We well engineered a small diagnostic tool to monitor PO2, minimally invasive, able to monitor real-time O2 in vivo complex environments.

Morphology dependent adsorption of methylene blue on trititanate nanoplates and nanotubes prepared by the hydrothermal treatment of TiO2

2016 ◽  
Vol 75 (2) ◽  
pp. 350-357
Author(s):  
Graham Dawson ◽  
Wei Chen ◽  
Luhua Lu ◽  
Kai Dai
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Pore Volume ◽  
Hydrothermal Reaction ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Adsorption Properties

The adsorption properties of two nanomorphologies of trititanate, nanotubes (TiNT) and plates (TiNP), prepared by the hydrothermal reaction of concentrated NaOH with different phases of TiO2, were examined. It was found that the capacity for both morphologies towards methylene blue (MB), an ideal pollutant, was extremely high, with the TiNP having a capacity of 130 mg/g, higher than the TiNT, whose capacity was 120 mg/g at 10 mg/L MB concentration. At capacity, the well-dispersed powders deposit on the floor of the reaction vessel. The two morphologies had very different structural and adsorption properties. TiNT with high surface area and pore volume exhibited exothermic monolayer adsorption of MB. TiNP with low surface area and pore volume yielded a higher adsorption capacity through endothermic multilayer adsorption governed by pore diffusion. TiNP exhibited a higher negative surface charge of −23 mV, compared to −12 mV for TiNT. The adsorption process appears to be an electrostatic interaction, with the cationic dye attracted more strongly to the nanoplates, resulting in a higher adsorption capacity and different adsorption modes. We believe this simple, low cost production of high capacity nanostructured adsorbent material has potential uses in wastewater treatment.

Highly active mixed-valent MnOxspheres constructed by nanocrystals as efficient catalysts for long-cycle Li–O2batteries

2016 ◽  
Vol 4 (43) ◽  
pp. 17129-17137 ◽  
Author(s):  
Sanpei Zhang ◽  
Zhaoyin Wen ◽  
Yang Lu ◽  
Xiangwei Wu ◽  
Jianhua Yang
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Long Cycle ◽  
Highly Active

We demonstrate a low-cost and facile strategy to synthesize mixed-valent MnOxspheres constructed from nanocrystals (~5 nm), containing MnII, MnIII, and MnIVspecies. Such highly active mixed-valent MnOxspheres with high surface area greatly improve the performance of Li–O2batteries.

scholarly journals Current Trends in Nanoporous Anodized Alumina Platforms for Biosensing Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-24 ◽  
Author(s):  
Ganesan Sriram ◽  
Pravin Patil ◽  
Mahesh P. Bhat ◽  
Raveendra M. Hegde ◽  
Kanalli V. Ajeya ◽  
...  
Keyword(s):  
Real Time ◽  
Surface Area ◽  
Chemical Stability ◽  
High Surface ◽  
High Surface Area ◽  
Key Factors ◽  
Current Trends ◽  
Anodization Process ◽  
Recent Trends ◽  
Detection Of Biomolecules

Pristine aluminum (Al) has received great deal of attention on fabrication of nanoporous anodized alumina (NAA) with arrays of nanosized uniform pores with controllable pore sizes and lengths by the anodization process. There are many applications of NAA in the field of biosensors due to its numerous key factors such as ease of fabrication, high surface area, chemical stability and detection of biomolecules through bioconjugation of active molecules, its rapidness, and real-time monitoring. Herein, we reviewed the recent trends on the fabrication of NAA for high sensitive biosensor platforms like bare sensors, gold coated sensors, multilayer sensors, and microfluidic device supported sensors for the detection of various biomolecules. In addition, we have discussed the future prospectus about the improvement of NAA based biosensors for the detection of biomolecules.

In vitro and preliminary in vivo toxicity screening of high-surface-area TiO2–chondroitin-4-sulfate nanocomposites for bone regeneration application

2015 ◽  
Vol 128 ◽  
pp. 347-356 ◽  
Author(s):  
Kavitha Kandiah ◽  
Rajendran Venkatachalam ◽  
Chunyan Wang ◽  
Suresh Valiyaveettil ◽  
Kumaresan Ganesan
Keyword(s):  
Bone Regeneration ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Toxicity Screening ◽  
In Vivo Toxicity

Reduction of bis(Oxalato)Borate on a High Surface Area Carbon Electrode

2008 ◽  
Vol 1127 ◽  
Author(s):  
John Flynn ◽  
Carl Schlaikjer
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Lithium Ion ◽  
Potential Range ◽  
Electrolytic Properties ◽  
Extensive Exchange ◽  
Soluble Species ◽  
Wide Potential

ABSTRACTLithium bis(oxalato)borate (LiBOB) has gained widespread interest as an electrolyte salt for lithium ion batteries because of its high conductivity, low cost, thermal stability, and adequate solubility in many organic solvents [1]. Cyclic voltammetric data taken on platinum [2] and carbon [3] indicate electrochemical stability over a wide potential range.We show that bis(oxalato)borate (BOB) can be reduced at about 1.75 volts anodic to lithium, by discharging electrolytes at low current density (0.1 mA/cm2) on high surface area carbon electrodes containing a mixture of acetylene and Ketjen carbon blacks. The evidence includes discharge profiles and 11B NMR data. The behavior of discharge plateaus indicates that BOB is reduced to a soluble species with electrolytic properties, and the appearance of a broad 11B NMR peak in the electrolyte indicates that the reduced species undergoes extensive exchange.

scholarly journals Silica Nanoparticles for Biomedical Application: Challenges and Opportunities

2020 ◽  
Author(s):  
E.A. Mun ◽  
B.A. Zhaisanbayeva
Keyword(s):  
Silica Nanoparticles ◽  
Surface Area ◽  
Biomedical Application ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Drug Carriers ◽  
High Reactivity ◽  
Diagnostic Tools ◽  
Gene Delivery Vectors

Over the past few decades, nanoparticles have been attracting significant attention of researches in chemical, biomedical, pharmaceutical sciences, due to their unique physicochemical properties. This includes ultra small size, large surface area, good biocompatibility and high reactivity. In particular, nanoparticles are promising for pharmaceutical and biomedical fields, as they can be applied as drug carriers and diagnostic tools. Among nanomaterials for biomedical application, silica nanoparticles exhibit great potential due to their straightforward synthesis and separation, low cost, safety, biocompatibility and possibility to further functionalization. Silica nanoparticles have been attractive for pharmaceutical science due to their unique properties, such as tunable size, high surface area and large pore volume, and potential in biomedical application as drug and gene delivery vectors and bioimaging agents. However, some of their properties remain poorly investigated. This short communication discusses the main routes for synthesis of silica nanoparticles, their properties and opportunities for their application in pharmaceutical and biomedical industries, as well as a few challenges in the development of silica-based systems that need to be overcome.

Low voltage electrolyte-gated organic transistors making use of high surface area activated carbon gate electrodes

2014 ◽  
Vol 2 (28) ◽  
pp. 5690-5694 ◽  
Author(s):  
J. Sayago ◽  
F. Soavi ◽  
Y. Sivalingam ◽  
F. Cicoira ◽  
C. Santato
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Low Voltage ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Reference Electrode ◽  
Organic Transistors ◽  
Gate Electrodes ◽  
External Reference

The use of high surface area, low cost, activated carbon gate electrodes enables low voltage (sub-1 V) operation in ionic liquid-gated organic transistors and renders unnecessary the presence of an external reference electrode to monitor the channel potential.

Preparation and Characterization of Rice Husk Ash for Adsorption of Phenol from Aqueous Solutions

2014 ◽  
Vol 625 ◽  
pp. 498-502
Author(s):  
Samah B. Daffalla ◽  
Hilmi Mukhtar ◽  
Maizatul S. Shaharun
Keyword(s):  
Aqueous Solutions ◽  
Surface Area ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Physiochemical Properties ◽  
Pseudo Second Order

In this research, the development of three (3) low-cost adsorbent materials from abundant waste rice husk was achieved via thermal treatment. The physiochemical properties of the developed adsorbents were evaluated. Their adsorption behaviours in batch system were evaluated for the removal of phenol from aqueous solutions by varying the pH (2 to 10). It was found that, the rice husk ash burned a 400oC for 1hr ‘RHA400,1’ has the highest surface area (201.36 m2.g-1) followed by RHA300,4(87.08 m2.g-1) and RHA600,1(43.22 m2.g-1), respectively. RHA400,1had shown the highest removal efficiency followed by RHA300,4and RHA600,1, towards phenol due to high surface area and porosity. The maximum uptake of phenol was found at pH 4. The adsorption kinetics was well described by both pseudo-second order and the Elovich models.

scholarly journals Modification of Microelectrode Arrays with High Surface Area Dendritic Platinum 3D Structures: Enhanced Sensitivity for Oxygen Detection in Ionic Liquids

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 735 ◽  
Author(s):  
Ghulam Hussain ◽  
Anthony O’Mullane ◽  
Debbie Silvester
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
3D Structures ◽  
Surface Areas ◽  
Enhanced Sensitivity ◽  
Redox Active ◽  
Low Concentrations ◽  
One Step

Electrochemical gas sensors are often used for identifying and quantifying redox-active analyte gases in the atmosphere. However, for amperometric sensors, the current signal is usually dependent on the electroactive surface area, which can become small when using microelectrodes and miniaturized devices. Microarray thin-film electrodes (MATFEs) are commercially available, low-cost devices that give enhanced current densities compared to mm-sized electrodes, but still give low current responses (e.g., less than one nanoamp), when detecting low concentrations of gases. To overcome this, we have modified the surface of the MATFEs by depositing platinum into the recessed holes to create arrays of 3D structures with high surface areas. Dendritic structures have been formed using an additive, lead acetate (Pb(OAc)2) into the plating solution. One-step and two-step depositions were explored, with a total deposition time of 300 s or 420 s. The modified MATFEs were then studied for their behavior towards oxygen reduction in the room temperature ionic liquid (RTIL) [N8,2,2,2][NTf2]. Significantly enhanced currents for oxygen were observed, ranging from 9 to 16 times the current of the unmodified MATFE. The highest sensitivity was obtained using a two-step deposition with a total time of 420 s, and both steps containing Pb(OAc)2. This work shows that commercially-available microelectrodes can be favorably modified to give significantly enhanced analytical performances.

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