“Off–on–off” type of selectively pH-sensing 8-hydroxyquinoline-substituted gallium(iii) corrole

2019 ◽  
Vol 43 (46) ◽  
pp. 18012-18017 ◽  
Author(s):  
Fangjian Cai ◽  
Fei Xia ◽  
Yingxin Guo ◽  
Weihua Zhu ◽  
Bo Fu ◽  
...  
Keyword(s):  
Ph Sensing ◽  
Wide Region ◽  
Ph Values ◽  
Fluorescent Response

We herein reported the synthesis and pH sensing property of a novel gallium corrole derivatives based on 8-hydroxyquinoline. Ga-corrole derivative showed good fluorescent response upon changing the pH values in the wide region of pH 1 to 12.

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.

scholarly journals Real-time diagnosis of sentinel lymph nodes involved to breast cancer based on pH sensing through lipid synthesis of those cells

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Zohreh S. Miripour ◽  
Parisa Aghaee ◽  
Fereshteh Abbasvandi ◽  
Parisa Hoseinpour ◽  
Mohammad Parniani ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Real Time ◽  
Diagnostic Method ◽  
Carbonic Acid ◽  
Lipid Synthesis ◽  
Sentinel Lymph Nodes ◽  
Ph Sensing ◽  
Ph Values ◽  
Litmus Paper ◽  
Time Diagnosis

Abstract Lipid synthesis is the recently found metabolism of cancer cells after their metastasis to lymph nodes (LNs). Carbonic acid is the main byproduct of the lipid metabolism in such cells which resulted in acidification of LN ambient. Hence, calibrated pH sensing could be a diagnostic method to find involved LNs. Here, we designed a simple pH sensing method by a syringe containing sterile PBS and embedded by litmus paper to intraoperatively check the pH of LN fluid. Injected phosphate buffer saline (PBS) would homogenize the LN fluid and litmus needle would detect the pH of the LN. We presented an experimental pathological calibration for the pH values in correlation with cancerous states of the LNs. This system named metabolism based metastatic lymph diagnoser (MMLD) could be a real-time noninvasive tool for precise and fast diagnosis of involved LNs.

Evaluation of Acridine in Nafion as a Fluorescence-Lifetime-Based pH Sensor

2003 ◽  
Vol 57 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Alan G. Ryder ◽  
Sarah Power ◽  
Thomas J. Glynn
Keyword(s):  
Excited State ◽  
Fluorescence Lifetime ◽  
Light Emitting Diode ◽  
Ph Sensor ◽  
Average Lifetime ◽  
Ph Sensing ◽  
Light Emitting ◽  
Ph Response ◽  
Ph Values ◽  
The Impact

We report a novel fluorescence-lifetime-based pH sensing method that utilizes acridine incorporated into Nafion (AcNaf) as the fluorescent indicator. The AcNaf sensor is excited using a 380 nm light emitting diode (LED) and the fluorescence lifetimes are measured at 450 and 500 nm. The fluorescence behavior of acridine as a function of pH in aqueous phosphate buffers and incorporated into the Nafion membrane has been investigated. The results show that incorporating acridine into Nafion changes the apparent ground-state pKa from ∼5.45 to ∼9, while the apparent excited-state pKa* is only slightly changed (∼9.4 in 0.1 M phosphate buffer). The AcNaf film shows a good pH response with a change in average lifetime of ∼19 ns (at an emission wavelength of 450 nm) over the pH 8 to 10 range. We also show that excited-state protonation does not occur in the AcNaf sensor film and that chloride quenching cannot occur because of the permselective nature of Nafion. We also discuss how the unique structure of Nafion affects the fluorescence behavior of acridine at various pH values and examine the impact of buffer concentration on apparent pKa and pH sensing ability.

scholarly journals Weak acids induce PGE2 production in human oesophageal cells: novel mechanisms underlying GERD symptoms

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daichi Sadatomi ◽  
Toru Kono ◽  
Sachiko Mogami ◽  
Naoki Fujitsuka
Keyword(s):  
Transient Receptor Potential ◽  
Squamous Carcinoma ◽  
Weak Acid ◽  
Prostaglandin E ◽  
Ph Sensing ◽  
Weak Acids ◽  
Ph Values ◽  
Squamous Carcinoma Cells ◽  
Cox 2 ◽  
Gerd Symptoms

AbstractThe role of weak acids with pH values in the range of 4–7 has been implicated in the symptoms of gastroesophageal reflux disease (GERD). Prostaglandin E2 (PGE2) is associated with heartburn symptom in GERD patients; however, the precise productive mechanisms remain unclear. In this study, we revealed that exposure to weak acids increases PGE2 production with a peak at pH 4–5, slightly in human normal oesophageal cells (Het-1A), and robustly in oesophageal squamous carcinoma cells (KYSE-270). Release of PGE2 from the oesophageal mucosa was augmented by weak acid treatment in rat. Chenodeoxycholic acid (CDCA), a bile acid, upregulated cyclooxygenase-2 (COX-2) expression in Het-1A and KYSE-270 and induced PGE2 production in KYSE-270 cells. Weak acid-induced PGE2 production was significantly inhibited by cytosolic phospholipase A2 (cPLA2), ERK, and transient receptor potential cation channel subfamily V member 4 (TRPV4), a pH-sensing ion channel, inhibitors. Hangeshashinto, a potent inhibitor of COX-2, strongly decreased weak acid- and CDCA-induced PGE2 levels in KYSE-270. These results indicated that weak acids induce PGE2 production via TRPV4/ERK/cPLA2 in oesophageal epithelial cells, suggesting a role in GERD symptoms like heartburn. Interventions targeting pH values up to 5 may be necessary for the treatment of GERD.

Synthesis of Push-Pull Phenazines Possessing pH-Responsive Absorption Spectra and their Application in Selective Detection of Fe3+ Ions and Aromatics

Synlett ◽  
2018 ◽  
Vol 29 (08) ◽  
pp. 1014-1019 ◽  
Author(s):  
Subhadeep Banerjee ◽  
Apeksha Phadte ◽  
Anjan Chattopadhyay ◽  
P. Bhavana ◽  
Keisham Singh
Keyword(s):  
Ph Value ◽  
Theoretical Calculations ◽  
Oxidation Potential ◽  
Selective Detection ◽  
Ph Sensing ◽  
Ph Responsive ◽  
Spectrophotometric Detection ◽  
High Ph ◽  
Ph Values ◽  
Internal Charge Transfer

Phenazines bearing electron-donor and electron-acceptor groups with high pH-sensing behavior were synthesized in moderate to good yields. Theoretical calculations on the frontier molecular orbitals and experimental oxidation potential measurements under variable pH values provide evidence for extensive internal charge transfer at high pH value. The well-known strong affinity of the catecholate moiety present in our phenazines is utilized for spectrophotometric detection of Fe3+ ion. Fluorescence-quenching behavior of the prepared phenazines is utilized for detection and distinction of electron-rich and electron-poor aromatics.

Nanofabricated Sensing Electrodes in a Batteryless Endoluminal Sensing Telemeter for Diagnosis of Gastroesophageal Reflux Disease (GERD)

2010 ◽  
Author(s):  
Lun-Chen Hsu ◽  
Wen-Ding Huang ◽  
Shou-Jiang Tang ◽  
Stuart Spechler ◽  
H. F. Tibbals ◽  
...  
Keyword(s):  
Gastroesophageal Reflux Disease ◽  
Gastroesophageal Reflux ◽  
Reflux Disease ◽  
Sensor Data ◽  
Ph Sensing ◽  
Impedance Sensing ◽  
Ph Values ◽  
Sensing System ◽  
Dual Sensor ◽  
Wireless Capsule

Gastroesophageal reflux disease (GERD) is recognized the primary risk factor associated with esophageal cancers. Therefore, monitoring GERD symptoms accurately is important for early diagnosis of such cancers. In this work, interdigitated impedance sensing electrodes and nanofabricated IrOx-based pH sensing electrodes were made on the flexible substrates that can be easily embedded into an implantable device. The dual sensor electrodes were integrated into a batteryless wireless capsule packaged with biocompatible material for implant applications. The proposed sensing system has been tested with stimulated solutions of different pH values recording modulated sensor data in terms of frequency shifts to verify its performance. The experimental results showed that the impedance electrodes responded to ion content variations and the pH electrodes identified the pH values of various pH solutions. Our sensing system has demonstrated the ability to detect gastroesophageal reflux activities more accurately, which could help doctors to provide precise treatment methods, consequentially lowering the risks of esophageal cancer development.

Organelle-targeting surface-enhanced Raman scattering (SERS) nanosensors for subcellular pH sensing

Nanoscale ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 1622-1630 ◽  
Author(s):  
Yanting Shen ◽  
Lijia Liang ◽  
Shuqin Zhang ◽  
Dianshuai Huang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Raman Scattering ◽  
High Sensitivity ◽  
Surface Enhanced Raman Scattering ◽  
Ph Sensing ◽  
Ph Values ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Organelle Targeting

A series of surface-enhanced Raman scattering (SERS) nanosensors with high sensitivity and targeting function was prepared for the quantification and monitoring of pH values in mitochondria, nucleus, and lysosome.

scholarly journals Graphene-Based Raman Spectroscopy for pH Sensing of X-rays Exposed and Unexposed Culture Media and Cells

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2242 ◽  
Author(s):  
Carlo Camerlingo ◽  
Alessandro Verde ◽  
Lorenzo Manti ◽  
Roberta Meschini ◽  
Ines Delfino ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Ph Value ◽  
Culture Media ◽  
Biological Fluids ◽  
X Rays ◽  
Ph Sensing ◽  
X Ray ◽  
Graphene Layers ◽  
Ph Values ◽  
Metabolic Activities

Graphene provides a unique way of sensing the local pH level of substances on the micrometric scale, with important implications for the monitoring of cellular metabolic activities where proton excretion could occur. Accordingly, an innovative biosensing approach for the quantification of the pH value of biological fluids, to be used also with small amounts of fluids, was realized and tested. It is based on the use of micro-Raman spectroscopy to detect the modifications of the graphene doping level induced by the contact of the graphene with the selected fluids. The approach was preliminarily tested on aqueous solutions of known pH values. It was then used to quantify the pH values of cell culture media directly exposed to different doses of X-ray radiation and to media exposed to X-ray-irradiated cells. The Raman response of cells placed on graphene layers was also examined.

scholarly journals Optical pH Sensing in Milk: A Small Puzzle of Indicator Concentrations and the Best Detection Method

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 177
Author(s):  
Olga Voskoboynikova ◽  
Aleksey Sukhanov ◽  
Axel Duerkop
Keyword(s):  
Optical Sensors ◽  
Detection Method ◽  
Ph Sensor ◽  
Photometric Determination ◽  
Bromocresol Purple ◽  
Ph Sensing ◽  
Ph Indicator ◽  
Ph Values ◽  
Sensor Membrane ◽  
Precision And Accuracy

Optical chemical sensors can yield distinctively different responses that are dependent on the method applied for readout and evaluation. We therefore present a comprehensive study on the pH determined non-continuously with optical sensors in real milk samples by either photometry or colorimetry (via the RGB-readout of digital images) compared to the pH values obtained electrochemically by potentiometry. Additionally, the photometric determination of pH was conducted with single-wavelength and a dual wavelength ratiometric evaluation of the absorbance. It was found that both the precision and accuracy of the pH determined by photometry benefit from lower concentrations of bromocresol purple, which served as the pH indicator inside the sensor membrane. A further improvement is obtained by the ratiometric evaluation of the photometric sensor response. The pH values obtained from the colorimetric evaluation, however, gain in precision and accuracy if a higher concentration of the indicator is immobilized inside the sensor membrane. This has a major impact on the future fabrication of optical pH sensor membranes because they can be better tuned to match to the most precise and accurate range of the planned detection method.

Evaluation of dissolution properties of silymarin capsules at different pH values

Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
A Uzunovic ◽  
S Pilipovic ◽  
A Elezovic ◽  
A Sapcanin ◽  
O Rahic
Keyword(s):  
Ph Values ◽  
Dissolution Properties
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