Porous manganese–cobalt oxide microspheres with tunable oxidase mimicking activity for sulfide ion colorimetric detection

2020 ◽  
Vol 56 (90) ◽  
pp. 14098-14101
Author(s):  
Xue Wang ◽  
Shiya Feng ◽  
Daiping He ◽  
Ping Jiang
Keyword(s):  
Cobalt Oxide ◽  
High Efficiency ◽  
Colorimetric Detection ◽  
Sulfide Ion

Porous MnxCo1−xO microspheres derived from Mn–Co PBA with tunable oxidase-like activity and high efficiency in S2− colorimetric detection.

A simple strategy to construct cobalt oxide-based high-efficiency electrocatalysts with oxygen vacancies and heterojunctions

2019 ◽  
Vol 326 ◽  
pp. 134979 ◽  
Author(s):  
Junwei Chen ◽  
Fangmu Wang ◽  
Xiaopeng Qi ◽  
Hui Yang ◽  
Bojun Peng ◽  
...  
Keyword(s):  
Cobalt Oxide ◽  
Oxygen Vacancies ◽  
High Efficiency ◽  
Simple Strategy

Engineering morphologies of cobalt oxide/phosphate-carbon nanohybrids for high-efficiency electrochemical water oxidation and reduction

2021 ◽  
Vol 52 ◽  
pp. 139-146 ◽  
Author(s):  
Shan-Shan Xu ◽  
Xian-Wei Lv ◽  
Yan-Mei Zhao ◽  
Tie-Zhen Ren ◽  
Zhong-Yong Yuan
Keyword(s):  
Cobalt Oxide ◽  
Water Oxidation ◽  
High Efficiency

scholarly journals Co nanoparticles decorated with N-doped carbon nanotubes as high-efficiency catalysts with intrinsic oxidase-like property for colorimetric sensing

RSC Advances ◽  
2021 ◽  
Vol 11 (63) ◽  
pp. 39966-39977
Author(s):  
Tao Chen ◽  
Jinmin Cao ◽  
Xiaofang Bao ◽  
Yu Peng ◽  
Li Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Ascorbic Acid ◽  
High Efficiency ◽  
Colorimetric Detection ◽  
Hybrid Nanocomposite ◽  
Colorimetric Sensing ◽  
Naked Eye ◽  
Co Nanoparticles

In this work, we designed a Co@N-CNTs hybrid nanocomposite as an oxidase mimic for the colorimetric detection of ascorbic acid with the naked eye.

scholarly journals Ratiometric Colorimetric Detection of Nitrite Realized by Stringing Nanozyme Catalysis and Diazotization Together

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 280
Author(s):  
Mengzhu Wang ◽  
Peng Liu ◽  
Hengjia Zhu ◽  
Bangxiang Liu ◽  
Xiangheng Niu
Keyword(s):  
Detection Limit ◽  
Signal Analysis ◽  
High Efficiency ◽  
Colorimetric Assay ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Health It ◽  
Practical Applications ◽  
Higher Sensitivity

Due to the great threat posed by excessive nitrite in food and drinking water to human health, it calls for developing reliable, convenient, and low-cost methods for nitrite detection. Herein, we string nanozyme catalysis and diazotization together and develop a ratiometric colorimetric approach for sensing nitrite in food. First, hollow MnFeO (a mixture of Mn and Fe oxides with different oxidation states) derived from a Mn-Fe Prussian blue analogue is explored as an oxidase mimic with high efficiency in catalyzing the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) oxidation to blue TMBox, presenting a notable signal at 652 nm. Then, nitrite is able to trigger the diazotization of the product TMBox, not only decreasing the signal at 652 nm but also producing a new signal at 445 nm. Thus, the analyte-induced reverse changes of the two signals enable us to establish a ratiometric colorimetric assay for nitrite analysis. According to the above strategy, facile determination of nitrite in the range of 3.3–133.3 μM with good specificity was realized, providing a detection limit down to 0.2 μM. Compared with conventional single-signal analysis, our dual-signal ratiometric colorimetric mode was demonstrated to offer higher sensitivity, a lower detection limit, and better anti-interference ability against external detection environments. Practical applications of the approach in examining nitrite in food matrices were also verified.

scholarly journals Optical Temperature Control Unit and Convolutional Neural Network for Colorimetric Detection of Loop-Mediated Isothermal Amplification on a Lab-On-A-Disc Platform

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3207 ◽  
Author(s):  
Da Ye Seul Lim ◽  
Moo-Jung Seo ◽  
Jae Chern Yoo
Keyword(s):  
High Efficiency ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Control Unit ◽  
Dna Amplification ◽  
Heating System ◽  
Isothermal Amplification ◽  
Physical Contact ◽  
Loop Mediated Isothermal Amplification ◽  
Polymeric Substrates

Lab-on-a-disc (LOD) has emerged as a promising candidate for a point-of-care testing (POCT) device because it can effectively integrate complex fluid manipulation steps using multiple layers of polymeric substrates. However, it is still highly challenging to design and fabricate temperature measurement and heating system in non-contact with the surface of LOD, which is a prerequisite to successful realization of DNA amplification especially with a rotatable disc. This study presents a Lab-on-a-disc (LOD)-based automatic loop-mediated isothermal amplification (LAMP) system, where a thermochromic coating (<~420 µm) was used to distantly measure the chamber’s temperature and a micro graphite film was integrated into the chamber to remotely absorb laser beam with super high efficiency. We used a deep learning network to more consistently analyze the product of LAMP than we could with the naked eye. Consequently, both temperature heating and measurement were carried out without a physical contact with the surface of LOD. The experimental results show that the proposed approach, which no previous work has attempted, was highly effective in realizing LAMP in LOD.

Boosting the bifunctional electrocatalytic oxygen activities of CoOxnanoarrays with a porous N-doped carbon coating and their application in Zn–air batteries

2017 ◽  
Vol 5 (34) ◽  
pp. 17804-17810 ◽  
Author(s):  
Yongchao Hao ◽  
Yuqi Xu ◽  
Nana Han ◽  
Junfeng Liu ◽  
Xiaoming Sun
Keyword(s):  
Cobalt Oxide ◽  
Porous Carbon ◽  
Carbon Coating ◽  
High Efficiency ◽  
Catalytic Performance ◽  
Good Stability ◽  
Carbon Coated ◽  
Air Battery

A N-doped porous carbon coated cobalt oxide nanoarray electrode was prepared with excellent bifunctional oxygen catalytic performance, and demonstrated good stability and high efficiency in a Zn–air battery.

Cobalt oxide nanoparticles as a novel high-efficiency fiber coating for solid phase microextraction of benzene, toluene, ethylbenzene and xylene from aqueous solutions

2014 ◽  
Vol 822 ◽  
pp. 30-36 ◽  
Author(s):  
Mohammad Bagher Gholivand ◽  
Mojtaba Shamsipur ◽  
Mohammad Shamizadeh ◽  
Rostam Moradian ◽  
Bandar Astinchap
Keyword(s):  
Aqueous Solutions ◽  
Cobalt Oxide ◽  
Solid Phase Microextraction ◽  
High Efficiency ◽  
Solid Phase ◽  
Oxide Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Fiber Coating ◽  
Benzene Toluene

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

1986 ◽  
Vol 44 ◽  
pp. 684-687
Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
High Efficiency ◽  
Fiber Optic ◽  
Image Intensifier ◽  
Detector System ◽  
Detector Plane ◽  
Secondary Electrons ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

Sign in / Sign up

Export Citation Format

Share Document