scholarly journals Protoporphyrin IX Based All-Solid-State Ion-Selective Electrodes for Choline Determination In Vitro

2021 ◽  
Vol 11 (12) ◽  
pp. 5549
Author(s):  
You Wang ◽  
Siyuan Ma ◽  
Hongqun Zou ◽  
Zhenyu Wu ◽  
Zhiyuan Luo ◽  
...  
Keyword(s):  
Solid State ◽  
Protoporphyrin Ix ◽  
Conductive Polymer ◽  
Temperature Stability ◽  
Standard Addition ◽  
Gold Wire ◽  
Fast Response ◽  
Ion Selective Electrodes ◽  
Poly Styrene Sulfonate

Protoporphyrin IX-based all-solid-state choline (Ch) ion-selective electrodes (ISEs) were fabricated and characterized. Poly (3,4-ethylene dioxythiophene) doped with poly (styrene sulfonate) (PEDOT/PSS) functioning as an ion-to-electron transducer was electropolymerized on the gold wire (0.5 mm diameter). The conductive polymer was covered with a Ch selective membrane containing protoporphyrin IX as an ionophore, which exhibited a lower detection limit of 0.49 μM with the potentiometric method. The Ch sensor performed a wide linear range from 1 μM to 1 mM, a fast response time of less than 5 s, and a decent selectivity of common inorganic and organic ions in the human body. Characteristics such as pH and temperature stability, life span, reproducibility and repeatability were also investigated to be satisfied. With the background of artificial cerebrospinal fluid, the recovery rate in 10−5 M of Ch solution was measured by the standard addition method, revealing the potential for biological application.

Water uptake in the hydrophilic poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) solid-contact of all-solid-state polymeric ion-selective electrodes

The Analyst ◽  
2011 ◽  
Vol 136 (16) ◽  
pp. 3252 ◽  
Author(s):  
Jean-Pierre Veder ◽  
Roland De Marco ◽  
Graeme Clarke ◽  
San Ping Jiang ◽  
Kathryn Prince ◽  
...  
Keyword(s):  
Solid State ◽  
Water Uptake ◽  
Ion Selective Electrodes ◽  
Solid Contact ◽  
Styrene Sulfonate ◽  
Poly Styrene Sulfonate

scholarly journals Solid-Contact Ion-Selective Electrodes for Histamine Determination

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6658
Author(s):  
Siyuan Ma ◽  
You Wang ◽  
Wei Zhang ◽  
Ye Wang ◽  
Guang Li
Keyword(s):  
Biological Fluids ◽  
Gold Wire ◽  
Fast Response ◽  
Ion Selective Electrodes ◽  
Solid Contact ◽  
Long Term Stability ◽  
Artificial Cerebrospinal Fluid ◽  
Selective Membrane ◽  
Ph Range

Solid-contact ion-selective electrodes for histamine (HA) determination were fabricated and studied. Gold wire (0.5 mm diameter) was coated with poly(3,4-ethlenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) as a solid conductive layer. The polyvinyl chloride matrix embedded with 5,10,15,20-tetraphenyl(porphyrinato)iron(iii) chloride as an ionophore, 2-nitrophenyloctyl ether as a plasticizer and potassium tetrakis(p-chlorophenyl) borate as an ion exchanger was used to cover the PEDOT:PSS layer as a selective membrane. The characteristics of the HA electrodes were also investigated. The detection limit of 8.58 × 10−6 M, the fast response time of less than 5 s, the good reproducibility, the long-term stability and the selectivity in the presence of common interferences in biological fluids were satisfactory. The electrode also performed stably in the pH range of 7–8 and the temperature range of 35–41 °C. Additionally, the recovery rate of 99.7% in artificial cerebrospinal fluid showed the potential for the electrode to be used in biological applications.

scholarly journals Systematic Review and Meta-Analysis of In Vitro Anti-Human Cancer Experiments Investigating the Use of 5-Aminolevulinic Acid (5-ALA) for Photodynamic Therapy

2021 ◽  
Vol 14 (3) ◽  
pp. 229
Author(s):  
Yo Shinoda ◽  
Daitetsu Kato ◽  
Ryosuke Ando ◽  
Hikaru Endo ◽  
Tsutomu Takahashi ◽  
...  
Keyword(s):  
Systematic Review ◽  
Photodynamic Therapy ◽  
Aminolevulinic Acid ◽  
Human Cancer ◽  
Meta Analysis ◽  
Protoporphyrin Ix ◽  
Cell Types ◽  
Amino Acid Derivative ◽  
Photodynamic Diagnosis

5-Aminolevulinic acid (5-ALA) is an amino acid derivative and a precursor of protoporphyrin IX (PpIX). The photophysical feature of PpIX is clinically used in photodynamic diagnosis (PDD) and photodynamic therapy (PDT). These clinical applications are potentially based on in vitro cell culture experiments. Thus, conducting a systematic review and meta-analysis of in vitro 5-ALA PDT experiments is meaningful and may provide opportunities to consider future perspectives in this field. We conducted a systematic literature search in PubMed to summarize the in vitro 5-ALA PDT experiments and calculated the effectiveness of 5-ALA PDT for several cancer cell types. In total, 412 articles were identified, and 77 were extracted based on our inclusion criteria. The calculated effectiveness of 5-ALA PDT was statistically analyzed, which revealed a tendency of cancer-classification-dependent sensitivity to 5-ALA PDT, and stomach cancer was significantly more sensitive to 5-ALA PDT compared with cancers of different origins. Based on our analysis, we suggest a standardized in vitro experimental protocol for 5-ALA PDT.

scholarly journals Alcohol-based highly conductive polymer for conformal nanocoatings on hydrophobic surfaces toward a highly sensitive and stable pressure sensor

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jung Joon Lee ◽  
Srinivas Gandla ◽  
Byeongjae Lim ◽  
Sunju Kang ◽  
Sunyoung Kim ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Mechanical Stability ◽  
Exchange Process ◽  
Conductive Polymer ◽  
High Sensitivity ◽  
Fast Response ◽  
Pdms Surface ◽  
Practical Applications ◽  
Sensor Applications ◽  
Water Based

Abstract Conformal and ultrathin coating of highly conductive PEDOT:PSS on hydrophobic uneven surfaces is essential for resistive-based pressure sensor applications. For this purpose, a water-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) solution was successfully exchanged to an organic solvent-based PEDOT:PSS solution without any aggregation or reduction in conductivity using the ultrafiltration method. Among various solvents, the ethanol (EtOH) solvent-exchanged PEDOT:PSS solution exhibited a contact angle of 34.67°, which is much lower than the value of 96.94° for the water-based PEDOT:PSS solution. The optimized EtOH-based PEDOT:PSS solution exhibited conformal and uniform coating, with ultrathin nanocoated films obtained on a hydrophobic pyramid polydimethylsiloxane (PDMS) surface. The fabricated pressure sensor showed high performances, such as high sensitivity (−21 kPa−1 in the low pressure regime up to 100 Pa), mechanical stability (over 10,000 cycles without any failure or cracks) and a fast response time (90 ms). Finally, the proposed pressure sensor was successfully demonstrated as a human blood pulse rate sensor and a spatial pressure sensor array for practical applications. The solvent exchange process using ultrafiltration for these applications can be utilized as a universal technique for improving the coating property (wettability) of conducting polymers as well as various other materials.

Enhanced Performance of I2-Free Solid-State Dye-Sensitized Solar Cells with Conductive Polymer up to 6.8%

2011 ◽  
Vol 21 (24) ◽  
pp. 4633-4639 ◽  
Author(s):  
Jeonghun Kim ◽  
Jong Kwan Koh ◽  
Byeonggwan Kim ◽  
Sung Hoon Ahn ◽  
Hyungju Ahn ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solid State ◽  
Dye Sensitized Solar Cells ◽  
Conductive Polymer ◽  
Dye Sensitized ◽  
Sensitized Solar Cells
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