In Situ Nanocoating on Porous Pyrolyzed Paper Enables Antibiofouling and Sensitive Electrochemical Analyses in Biological Fluids

2022 ◽  
Author(s):  
Caroline Y. N. Nicoliche ◽  
Aline M. Pascon ◽  
Ítalo R. S. Bezerra ◽  
Ana C. H. de Castro ◽  
Gabriel R. Martos ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Electrochemical Analyses

Fabrication of chemically and in situ modified carbon paste electrodes for the potentiometric determination of chlorpromazine HCl in pure pharmaceutical preparations, urine and serum

2017 ◽  
Vol 41 (24) ◽  
pp. 15612-15624 ◽  
Author(s):  
Gehad G. Mohamed ◽  
Eman Y. Z. Frag ◽  
M. A. Zayed ◽  
M. M. Omar ◽  
Sally E. A. Elashery
Keyword(s):  
Biological Fluids ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Carbon Paste ◽  
Chlorpromazine Hydrochloride ◽  
Carbon Paste Electrodes ◽  
Urine And Serum ◽  
Modified Carbon Paste Electrodes

Newly developed modified and in situ modified carbon paste sensors were developed for the determination of chlorpromazine hydrochloride (CPZHC) in pharmaceutical formulations and biological fluids (urine and serum).

scholarly journals A platinum black-modified microelectrode for in situ olanzapine detection in microliter volumes of undiluted serum

2020 ◽  
Vol 127 (2) ◽  
pp. 291-299 ◽  
Author(s):  
Rajendra P. Shukla ◽  
Robert H. Belmaker ◽  
Yuly Bersudsky ◽  
Hadar Ben-Yoav
Keyword(s):  
Liquid Chromatography ◽  
Real Time ◽  
Psychotic Disorders ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
In Situ Monitoring ◽  
Blood Levels ◽  
Platinum Black ◽  
Serum Samples

AbstractOlanzapine is a thienobenzodiazepine compound. It is one of the newer types of antipsychotic drugs used in the treatment of schizophrenia and other psychotic disorders. Several methods have been reported for analyzing olanzapine in its pure form or combined with other drugs and in biological fluids. These methods include high-performance liquid chromatography and liquid chromatography-tandem mass spectroscopy. Although many of the reported methods are accurate and sensitive, they require the use of sophisticated equipment, lack in situ analysis, and require expensive reagents. Moreover, several of these methods are cumbersome, require prolonged sample pretreatment, strict control of pH, and long reaction times. Here we present the development of a miniaturized electrochemical sensor that will enable minimally invasive, real-time, and in situ monitoring of olanzapine levels in microliter volumes of serum samples. For this purpose, we modified a microfabricated microelectrode with a platinum black film to increase the electrocatalytic activity of the microelectrode towards olanzapine oxidation; this improved the overall selectivity and sensitivity of the sensor. We observed in recorded voltammograms the anodic current dose response characteristics in microliter volumes of olanzapine-spiked serum samples that resulted in a limit of detection of 28.6 ± 1.3 nM and a sensitivity of 0.14 ± 0.02 µA/cm2 nM. Importantly, the platinum black-modified microelectrode exhibited a limit of detection that is below the clinical threshold (65–130 nM). Further miniaturizing and integrating such sensors into point-of-care devices provide real-time monitoring of olanzapine blood levels; this will enable treatment teams to receive feedback and administer adjustable olanzapine therapy.

scholarly journals Shape-preserving amorphous-to-crystalline transformation of CaCO3 revealed by in situ TEM

2020 ◽  
Vol 117 (7) ◽  
pp. 3397-3404 ◽  
Author(s):  
Zhaoming Liu ◽  
Zhisen Zhang ◽  
Zheming Wang ◽  
Biao Jin ◽  
Dongsheng Li ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Biological Fluids ◽  
Amorphous State ◽  
In Situ Tem ◽  
Dependent Manner ◽  
Amorphous Calcium Carbonate ◽  
Shape Preserving ◽  
Structural Water ◽  
Concentration Dependent Manner

Organisms use inorganic ions and macromolecules to regulate crystallization from amorphous precursors, endowing natural biominerals with complex morphologies and enhanced properties. The mechanisms by which modifiers enable these shape-preserving transformations are poorly understood. We used in situ liquid-phase transmission electron microscopy to follow the evolution from amorphous calcium carbonate to calcite in the presence of additives. A combination of contrast analysis and infrared spectroscopy shows that Mg ions, which are widely present in seawater and biological fluids, alter the transformation pathway in a concentration-dependent manner. The ions bring excess (structural) water into the amorphous bulk so that a direct transformation is triggered by dehydration in the absence of morphological changes. Molecular dynamics simulations suggest Mg-incorporated water induces structural fluctuations, allowing transformation without the need to nucleate a separate crystal. Thus, the obtained calcite retains the original morphology of the amorphous state, biomimetically achieving the morphological control of crystals seen in biominerals.

scholarly journals Particle-by-Particle in Situ Characterization of the Protein Corona via Real-Time 3D Single Particle Tracking Microscopy

2021 ◽  
Author(s):  
Xiaochen Tan ◽  
Kevin Welsher
Keyword(s):  
Real Time ◽  
Particle Tracking ◽  
Single Particle ◽  
Biological Fluids ◽  
Protein Corona ◽  
Single Particle Tracking ◽  
Ex Situ ◽  
High Background ◽  
Particle Nature

<p>Nanoparticles (NPs) adsorb proteins when exposed to biological fluids, forming a dynamic protein corona that affects their fate in biological environments. A comprehensive understanding of the protein corona is lacking due to the inability of current techniques to precisely measure the full corona <i>in situ</i> at the single particle level. Herein, we introduce a 3D real-time single-particle tracking spectroscopy to "lock-on" to single freely-diffusing polystyrene NPs and probe their individual protein coronas. The diffusive motions of the tracked NPs enable quantification of the "hard corona" using mean-squared displacement analysis. Critically, this method's particle-by-particle nature enabled a lock-in-type frequency filtering approach to extract the full protein corona, despite the typically confounding effect of high background signal from unbound proteins. From these results, the dynamic <i>in situ </i>full protein corona is observed to contain double the number of proteins than are observed in the <i>ex situ</i> measured "hard" protein corona.</p><br>

Improved analysis of picomole quantities of lithium, sodium, and potassium in biological fluids

1994 ◽  
Vol 267 (4) ◽  
pp. F695-F701 ◽  
Author(s):  
M. Shalmi ◽  
J. D. Kibble ◽  
J. P. Day ◽  
P. Christensen ◽  
J. C. Atherton
Keyword(s):  
Biological Fluids ◽  
Atomic Absorption Spectrophotometry ◽  
Sodium Reabsorption ◽  
Interference Effects ◽  
Puncture Site ◽  
Matrix Interferences ◽  
Sample Matrix ◽  
Absorption Spectrophotometry ◽  
Sodium And Potassium

The analysis of picomolar lithium, sodium, and potassium by electrothermal atomic absorption spectrophotometry was studied using a Perkin-Elmer Zeeman 3030 spectrophotometer. With ordinary pyrolytically coated graphite tubes, a number of interference effects associated with the sample matrix were observed. In particular, the lithium and potassium absorbance signal was depressed by chloride, an effect shown to be dependent on the preatomization heating. When an in situ tantalum-coated atomization surface was used, matrix interferences observed in lithium and potassium analyses were abolished, and the linear range for the potassium assay was extended. Technical difficulties encountered during sodium analysis at the primary wavelength were effectively circumvented by analysis at a less-sensitive wavelength (303.3 nm), at which tantalum coating also prevented significant chloride interference. The improved microanalyses were employed to reevaluate the handling of lithium, sodium, and potassium along the proximal convoluted tubule (PCT) of the anesthetized rat. The average tubular fluid-to-plasma concentration ratios for lithium [(TF/P)Li] and sodium [(TF/P)Na] were 1.13 +/- 0.08, n = 26, and 0.99 +/- 0.07 (n = 26), respectively. The tubular fluid-to-plasma ultrafiltrate concentration ratio for potassium [(TF/UF)K] was 1.09 +/- 0.05 (n = 13). Ratios did not change significantly with puncture site along the PCT for any of the ions. (TF/P)Li and (TF/UF)K were significantly greater than (TF/P)Na, indicating that lithium and potassium reabsorption do not directly parallel sodium reabsorption in the PCT.

scholarly journals Boron Doped Diamond Electrodes for Direct Measurement in Biological Fluids: An In Situ Regeneration Approach

2012 ◽  
Vol 160 (1) ◽  
pp. H67-H73 ◽  
Author(s):  
Raphael Kiran ◽  
Emmanuel Scorsone ◽  
Jacques de Sanoit ◽  
Jean-Charles Arnault ◽  
Pascal Mailley ◽  
...  
Keyword(s):  
Direct Measurement ◽  
Biological Fluids ◽  
Diamond Electrodes ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
In Situ Regeneration

scholarly journals Particle-by-Particle in Situ Characterization of the Protein Corona via Real-Time 3D Single Particle Tracking Microscopy

2021 ◽  
Author(s):  
Xiaochen Tan ◽  
Kevin Welsher
Keyword(s):  
Real Time ◽  
Particle Tracking ◽  
Single Particle ◽  
Biological Fluids ◽  
Protein Corona ◽  
Single Particle Tracking ◽  
Ex Situ ◽  
High Background ◽  
Particle Nature

<p>Nanoparticles (NPs) adsorb proteins when exposed to biological fluids, forming a dynamic protein corona that affects their fate in biological environments. A comprehensive understanding of the protein corona is lacking due to the inability of current techniques to precisely measure the full corona <i>in situ</i> at the single particle level. Herein, we introduce a 3D real-time single-particle tracking spectroscopy to "lock-on" to single freely-diffusing polystyrene NPs and probe their individual protein coronas. The diffusive motions of the tracked NPs enable quantification of the "hard corona" using mean-squared displacement analysis. Critically, this method's particle-by-particle nature enabled a lock-in-type frequency filtering approach to extract the full protein corona, despite the typically confounding effect of high background signal from unbound proteins. From these results, the dynamic <i>in situ </i>full protein corona is observed to contain double the number of proteins than are observed in the <i>ex situ</i> measured "hard" protein corona.</p><br>

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