scholarly journals Photoactive carbogenic nanotracers with remarkable antimicrobial properties for pH-sensing applications

2020 ◽  
Author(s):  
Joanna Stachowska ◽  
Ella Gibbons ◽  
Antonios Kelarakis ◽  
Marta Krysmann
Keyword(s):  
Antimicrobial Properties ◽  
Ph Sensing ◽  
Sensing Applications

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

scholarly journals Near-Infrared pH Sensor Based on a SPEEK–Polyaniline Polyelectrolyte Complex Membrane

Proceedings ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 11 ◽  
Author(s):  
Nedal Y. Abu-Thabit
Keyword(s):  
Polyelectrolyte Complex ◽  
Near Infrared ◽  
Response Times ◽  
Oxidative Polymerization ◽  
Ph Sensor ◽  
Ph Sensing ◽  
Ph Values ◽  
Sensing Applications ◽  
Ph Range ◽  
Speek Membrane

A polyelectrolyte complex (PEC) membrane based on sulfonated poly (ether ether ketone) and polyaniline (SPEEK-PANI) was developed for pH sensing applications. Aniline was polymerized in the presence of the SPEEK membrane by using in situ chemical oxidative polymerization to yield an ionically crosslinked SPEEK-PANI membrane. The fabricated membrane exhibited sensitivity in the physiological pH range of 2–8. The PEC membrane pH sensor showed good absorption properties in the near-infrared region (NIR). The membrane showed fast response during a de-doping process (≈90 s), while longer response times are essential for doping processes from the alkaline/neutral pH region to the acidic pH region, which is attributed to the presence of highly acidic sulfonic acid groups with a high buffering capacity in the PEC membrane. The SPEEK-PANI membrane exhibited slightly higher water uptake compared to the neat SPEEK membrane. The membrane exhibited good stability, as it was stored in 1M HCl solution for more than 2 years without physical or visual deterioration. A preconditioning step in 1M HCl ensured that the results were reproducible and allows the pH sensor to be used repeatedly. The PEC sensor membranes are suitable for applications that start at low pH values and move upwards to higher pH values in the 2–8 pH range.

Photophysical properties and pH sensing applications of luminescent salicylaldehyde derivatives

2015 ◽  
Vol 42 (5) ◽  
pp. 5027-5048 ◽  
Author(s):  
Jiaoyan Liu ◽  
Jinghui Cheng ◽  
Xiaofeng Ma ◽  
Xiangge Zhou ◽  
Haifeng Xiang
Keyword(s):  
Photophysical Properties ◽  
Ph Sensing ◽  
Sensing Applications ◽  
Salicylaldehyde Derivatives

ChemInform Abstract: Molecular Photoionic Switches with an Internal Reference Channel for Fluorescent pH Sensing Applications.

ChemInform ◽  
2010 ◽  
Vol 28 (4) ◽  
pp. no-no
Author(s):  
A. P. DE SILVA ◽  
H. Q. N. GUNARATNE ◽  
T. GUNNLAUGSSON ◽  
P. L. M. LYNCH
Keyword(s):  
Ph Sensing ◽  
Reference Channel ◽  
Internal Reference ◽  
Sensing Applications

Novel sensing materials for harsh environment subsurface pH sensing applications

2015 ◽  
Author(s):  
Congjun Wang ◽  
Xin Su ◽  
Thomas D. Brown ◽  
Paul R. Ohodnicki
Keyword(s):  
Harsh Environment ◽  
Ph Sensing ◽  
Sensing Applications

scholarly journals Direct Femtosecond Laser Fabrication of Chemically Functionalized Ultra-Black Textures on Silicon for Sensing Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 401
Author(s):  
Yulia Borodaenko ◽  
Stanislav Gurbatov ◽  
Mikhail Tutov ◽  
Alexey Zhizhchenko ◽  
Sergei A. Kulinich ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Single Step ◽  
Ph Sensing ◽  
Surface Textures ◽  
High Performing ◽  
Self Organized ◽  
Sensing Applications ◽  
Signal Amplifier ◽  
Potential Applicability

Here, we present the single-step laser-assisted fabrication of anti-reflective hierarchical surface textures on silicon locally functionalized with a photoluminescent (PL) molecular nanolayer. Using femtosecond-laser ablation of commercial crystalline Si wafers placed under a layer of a solution containing rhodamine 6G (R6G) a triethoxysilyl derivative, we fabricated ordered arrays of microconical protrusions with self-organized nanoscale surface morphology. At the same time, the laser-induced temperature increase facilitated surface activation and local binding of the R6G derivative to the as-fabricated nanotextured surface. The produced dual-scale surface textures showed remarkable broadband (visible to near-IR) light-absorbing properties with an averaged reflectivity of around 1%, and the capping molecular nanolayer demonstrated a strongly enhanced PL yield. By performing a pH sensing test using the produced nanotextured substrate, we confirmed the retention of sensory properties of the molecules attached to the surface and validated the potential applicability of the high-performing liquid-assisted laser processing as a key technology for the development of innovative multifunctional sensing devices in which the textured substrate (e.g., ultra-black semiconductor) plays a dual role as a support and PL signal amplifier.

scholarly journals A Compact Ultrawideband Antenna Based on Hexagonal Split-Ring Resonator for pH Sensor Application

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2959 ◽  
Author(s):  
Mohammad Islam ◽  
Farhad Ashraf ◽  
Touhidul Alam ◽  
Norbahiah Misran ◽  
Kamarulzaman Mat
Keyword(s):  
Ring Resonator ◽  
Coupling Effect ◽  
Ph Sensor ◽  
Split Ring Resonator ◽  
Strip Line ◽  
Ph Sensing ◽  
Uwb Antenna ◽  
Split Ring ◽  
Electrical Length ◽  
Sensing Applications

A compact ultrawideband (UWB) antenna based on a hexagonal split-ring resonator (HSRR) is presented in this paper for sensing the pH factor. The modified HSRR is a new concept regarding the conventional square split-ring resonator (SSRR). Two HSRRs are interconnected with a strip line and a split in one HSRR is introduced to increase the electrical length and coupling effect. The presented UWB antenna consists of three unit cells on top of the radiating patch element. This combination of UWB antenna and HSRR gives double-negative characteristics which increase the sensitivity of the UWB antenna for the pH sensor. The proposed ultrawideband antenna metamaterial sensor was designed and fabricated on FR-4 substrate. The electrical length of the proposed metamaterial antenna sensor is 0.238 × 0.194 × 0.016 λ, where λ is the lowest frequency of 3 GHz. The fractional bandwidth and bandwidth dimension ratio were achieved with the metamaterial-inspired antenna as 146.91% and 3183.05, respectively. The operating frequency of this antenna sensor covers the bandwidth of 17 GHz, starting from 3 to 20 GHz with a realized gain of 3.88 dB. The proposed HSRR-based ultrawideband antenna sensor is found to reach high gain and bandwidth while maintaining the smallest electrical size, a highly desired property for pH-sensing applications.

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