An alternative approach to develop a highly sensitive and selective chemosensor for the colorimetric sensing of cyanide in water

An elastohydrodynamic lubrication model is proposed for line contacts under pressurized ambient conditions often encountered in hydraulic pumps, submarine machinery and many other submerged systems. It has been demonstrated that the film forming behavior under such conditions is essentially different from that in conventional elastohydrodynamic lubrication contacts. The numerical simulation results are regressed to develop new central and minimum film thickness equations for Newtonian fluids as functions of ambient pressure, speed, load, and material parameters. An alternative approach is also discussed which involves the use of existing film thickness formulas with ambient viscosity and pressure–viscosity coefficient pertaining to the desired pressure range. A film thickness enhancement of more than 100% over conventional elastohydrodynamic lubrication case is observed. This enhancement is shown to be highly sensitive to the pressure–viscosity coefficient. Besides, the effect of shear-thinning behavior is also investigated and it is found to lower the film thickness enhancement, especially at high ambient pressures.

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Hydrothermal synthesis of core–shell structured TbPO4:Ce3+@TbPO4:Gd3+nanocomposites for magnetic resonance and optical imaging

Dalton Transactions ◽

10.1039/c4dt00249k ◽

2014 ◽

Vol 43 (32) ◽

pp. 12321-12328 ◽

Cited By ~ 16

Author(s):

Xiao-yan Kuang ◽

Huan Liu ◽

Wen-yong Hu ◽

Yuan-zhi Shao

Keyword(s):

Hydrothermal Synthesis ◽

Magnetic Resonance ◽

Cancer Diagnosis ◽

Early Cancer ◽

Core Shell ◽

Promising Alternative ◽

Non Invasive ◽

Early Cancer Diagnosis ◽

Alternative Approach ◽

Highly Sensitive

Multi-modal imaging based on multifunctional nanoparticles provides deep, non-invasive and highly sensitive imaging and is a promising alternative approach that can improve the sensitivity of early cancer diagnosis.

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Mercaptosuccinic-Acid-Functionalized Gold Nanoparticles for Highly Sensitive Colorimetric Sensing of Fe(III) Ions

Chemosensors ◽

10.3390/chemosensors9100290 ◽

2021 ◽

Vol 9 (10) ◽

pp. 290

Author(s):

Nadezhda S. Komova ◽

Kseniya V. Serebrennikova ◽

Anna N. Berlina ◽

Svetlana M. Pridvorova ◽

Anatoly V. Zherdev ◽

...

Keyword(s):

Gold Nanoparticles ◽

Drinking Water ◽

Detection Limit ◽

Analytical Signal ◽

Colorimetric Sensor ◽

World Health ◽

Colorimetric Sensing ◽

Functionalized Gold Nanoparticles ◽

Mercaptosuccinic Acid ◽

Highly Sensitive

The development of reliable and highly sensitive methods for heavy metal detection is a critical task for protecting the environment and human health. In this study, a qualitative colorimetric sensor that used mercaptosuccinic-acid-functionalized gold nanoparticles (MSA-AuNPs) to detect trace amounts of Fe(III) ions was developed. MSA-AuNPs were prepared using a one-step reaction, where mercaptosuccinic acid (MSA) was used for both stabilization, which was provided by the presence of two carboxyl groups, and functionalization of the gold nanoparticle (AuNP) surface. The chelating properties of MSA in the presence of Fe(III) ions and the concentration-dependent aggregation of AuNPs showed the effectiveness of MSA-AuNPs as a sensing probe with the use of an absorbance ratio of A530/A650 as an analytical signal in the developed qualitative assay. Furthermore, the obvious Fe(III)-dependent change in the color of the MSA-AuNP solution from red to gray-blue made it possible to visually assess the metal content in a concentration above the detection limit with an assay time of less than 1 min. The detection limit that was achieved (23 ng/mL) using the proposed colorimetric sensor is more than 10 times lower than the maximum allowable concentration for drinking water defined by the World Health Organization (WHO). The MSA-AuNPs were successfully applied for Fe(III) determination in tap, spring, and drinking water, with a recovery range from 89.6 to 126%. Thus, the practicality of the MSA-AuNP-based sensor and its potential for detecting Fe(III) in real water samples were confirmed by the rapidity of testing and its high sensitivity and selectivity in the presence of competing metal ions.

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Polyacrylonitrile/CoCl2 Nanofibers Based Humidity Sensor for Human Breath and Ambient Humidity Monitoring

10.21203/rs.3.rs-313024/v1 ◽

2021 ◽

Author(s):

Xiaoqiang Li ◽

Pang Zengyuan ◽

Li Mengjuan ◽

Jin Yang

Keyword(s):

Humidity Sensor ◽

Dual Function ◽

Colorimetric Sensing ◽

Promising Candidate ◽

Human Breath ◽

Ambient Humidity ◽

Sem Image ◽

Hybrid Nanofibers ◽

Highly Sensitive ◽

Humidity Monitoring

Abstract A novel humidity sensor was constructed using the hybrid nanofibers of polyacrylonitrile/CoCl2 (PAN/CoCl2), which were fabricated by electrospinning. Scanning electron microscopy (SEM) image demonstrated that the diameter of PAN/CoCl2 nanofibers ranged from 100 - 500 nm. Energy-dispersive X-ray spectrometer (EDS) analysis confirmed that Co and Cl elements were homogeneously dispersed on the PAN nanofibers. CoCl2 on the surface of PAN nanofibers play a dual function in humidity sensing performances. First, CoCl2 serves as an indicator, which can change the color of nanofibers from blue to white-pink as the relative humidity changed from 11 to 98 %, to realize the colorimetric sensing. Second, CoCl2 could remarkably improve the electric sensing performance. As a result, the PAN/CoCl2 nanofibers offered much enhanced response currents compared to the pristine PAN nanofibers, as the humidity changed from RH 11 to 98 %. In addition, the PAN/CoCl2 nanofibers based humidity sensor was employed to monitor human breath and the ambient humidity, which demonstrated the excellent sensitivity of this humidity sensor. Therefore, we believe that the highly sensitive and simply designed PAN/CoCl2 humidity sensor is a promising candidate for various applications in the field of humidity monitoring.

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