Synthesis of Ag–Cu alloy nanosheets for ascorbic acid detection

2021 ◽  
Vol 11 (6) ◽  
pp. 1001-1006
Author(s):  
Lijun Kong ◽  
Jiahao Chen ◽  
Zehui Peng ◽  
Jiawei Zhang ◽  
Yuan Gao ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
High Sensitivity ◽  
Soft Template ◽  
Ascorbic Acid Concentration ◽  
Detection Range ◽  
Optical Absorbance ◽  
Cu Alloy ◽  
Enzyme Method ◽  
Ascorbic Acid Detection ◽  
Excellent Stability

Metal alloy nanosheets play a very important role as catalysts, which also show obvious advantages in the field of biosensor. Compared with traditional methods, such as enzyme method, gas chromatography or optical absorbance, the detection of ascorbic acid is simpler and more stable by spectroscopy. Ag–Cu alloy nanosheets with a thickness of about 1–3 nm and an average lateral size of 3–5 nm were synthesized in this study by the soft template method. These nanosheets were used to construct a sensor for measuring the concentration of ascorbic acid. The initial UV-Vis absorption peaks for the Ag–Cu alloy nanosheets in aqueous solution were effectively quenched upon addition of ascorbic acid. As the ascorbic acid concentration was in the range of 5–250 mmol/L changes, the UV absorbance intensity for the sensor also changed. Because of its wide detection range, high sensitivity, and excellent stability, the Ag–Cu alloy sensor method may be an excellent alternative to the traditional ascorbic acid measure method.

QDs Based Photoelectrochemical Sensors for Detection of Ascorbic Acid

2021 ◽  
Vol 1033 ◽  
pp. 77-81
Author(s):  
Li Ping Tu ◽  
Guo Wei Xu
Keyword(s):  
Quantum Dots ◽  
Ascorbic Acid ◽  
Acid Concentration ◽  
Bias Voltage ◽  
Fabrication Process ◽  
Acid Solutions ◽  
Ascorbic Acid Concentration ◽  
Detection Range ◽  
Photoelectrochemical Sensor ◽  
Ascorbic Acid Sensor

By fixing Quantum Dots (QDs) on gold electrodes with dithiol compounds, a novel Ascorbic Acid sensor without any redox mediator was desighed. First, the fabrication process of sensor was described.Sencond, the characteristics of the sensor were investigated. Third,the sensor was tested in Ascorbic Acid solutions of different concentrations.From the results,it shows that the performance of photoelectrochemical sensor were influenced by the bias voltage and the amplitude of photocurrent changed with the Ascorbic Acid concentration linearly in detection range.

Simultaneous determination of ascorbic acid, dopamine and uric acid at a nitrogen-doped carbon nanofiber modified electrode

RSC Advances ◽  
2015 ◽  
Vol 5 (16) ◽  
pp. 11925-11932 ◽  
Author(s):  
Jinying Sun ◽  
Libo Li ◽  
Xueping Zhang ◽  
Dong Liu ◽  
Simin Lv ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Carbon Nanofiber ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon ◽  
Small Biomolecules ◽  
Excellent Stability

This paper demonstrates high electrocatalytic activity of NCNF/GCE towards small biomolecules. The proposed electrochemical sensor exhibits good selectivity, high sensitivity and excellent stability towards AA, DA and UA simultaneous detection.

Rapid synthesis of hollow Ni(OH)2 with low-crystallinity for the electrochemical detection of ascorbic acid with high sensitivity

RSC Advances ◽  
2016 ◽  
Vol 6 (49) ◽  
pp. 43598-43604 ◽  
Author(s):  
Delun Chen ◽  
Yang Cao ◽  
Yong Chen ◽  
Wei Huang ◽  
Bingrong Wang ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Detection Limit ◽  
Electrochemical Detection ◽  
High Sensitivity ◽  
Linear Range ◽  
Rapid Synthesis ◽  
Ascorbic Acid Detection ◽  
Low Crystallinity

Ni(OH)2 performed good properties to ascorbic acid detection with the linear range of 10 μM to 0.20 mM, the detection limit of 3 μM (S/N = 3). The sensitivity is 1747.71 μA mM−1 cm−2, which is due to the hollow Ni(OH)2 with low crystallinity.

The Effect of Stress and Warfarin on the Adrenal Gland in Relation to Spontaneous Hemorrhage, as Judged by Measurement of Adrenal Ascorbic Acid and Serum Corticosterone

1971 ◽  
Vol 26 (02) ◽  
pp. 275-288 ◽  
Author(s):  
S Chattopadhyay ◽  
D. D Johnson ◽  
G. J Millar ◽  
L. B Jaques
Keyword(s):  
Ascorbic Acid ◽  
Acid Concentration ◽  
Ascorbic Acid Concentration ◽  
Corticosterone Concentration ◽  
Serum Corticosterone ◽  
Spontaneous Hemorrhage ◽  
Combined Action ◽  
Series Of Experiments ◽  
Pituitary Adrenal Axis

SummaryRats were subjected to the following procedures: No treatment, Stressor (10% NaCl i.p.), Warfarin for 7 days, Stressor followed by Warfarin; and groups were sacrificed at intervals for assessment of spontaneous hemorrhage and of adrenal ascorbic acid concentration. There was no hemorrhage in the no treatment and stressor groups; some hemorrhage in the warfarin group; profound hemorrhage with Warfarin + Stressor. The adrenal ascorbic acid concentration was found to be lower, 8 h and again 5 days after stress, and remained lower in the warfarin + stress animals. Warfarin had no effect on adrenal ascorbic acid level.In another series of experiments in which the stress consisted of an electric current to the cage floor for 6 sec over 15 min, rats were sacrificed daily for determination of serum corticosterone concentration and occurrence of spontaneous hemorrhage. There was a statistically significant increase of serum corticosterone concentration with stress, warfarin and combined warfarin and stress treatments (P< 0.001 for all three variables). There was a significant correlation (r = 0.96 and 0.89, P< 0.01) for serum corticosterone concentration with hemorrhage score and incidence of hemorrhage in stressed rats receiving warfarin, but not in those receiving only warfarin. The results indicate an activation, rather than an exhaustion, of the pituitary-adrenal axis during the combined action of anticoagulant and stress, which results in the development of spontaneous hemorrhage.

PLASMA CORTICOSTEROID LEVELS AND ADRENAL ASCORBIC ACID AFTER INTRAVENOUS CORTICOTROPHIN INJECTIONS AND »STRESSFUL« STIMULI IN THE RAT

1962 ◽  
Vol 39 (4) ◽  
pp. 527-538 ◽  
Author(s):  
Pavo Hedner ◽  
Claus Rerup
Keyword(s):  
Ascorbic Acid ◽  
Abdominal Surgery ◽  
Response Curve ◽  
Significant Rise ◽  
Blocking Effect ◽  
High Dose ◽  
Ascorbic Acid Concentration ◽  
Unilateral Adrenalectomy ◽  
Subcutaneous Injections ◽  
Hypophysectomized Rats

ABSTRACT Measurements of plasma corticosteroid levels and adrenal ascorbic acid concentration in steroid blocked and hypophysectomized rats were performed. It was found that prednisolone and dexamethasone were effective in blocking endogenous corticotrophin release within 3–4 hours after subcutaneous injection. These agents also prevented completely the normally occurring rise in plasma corticoid levels after exposure of the rats to ether. Abdominal surgery (unilateral adrenalectomy) resulted in a slight but significant rise in plasma corticoid levels in spite of dexamethasone blockade. The values of adrenal ascorbic acid were not affected significantly. The blocking effect of two daily subcutaneous injections of a high dose of dexamethasone persisted for about one week after the last injection. The sensitivity of the plasma corticoid response was essentially the same in hypophysectomized and dexamethasone blocked rats. The lower part of the log dose response curve was found to be clearly non-linear in the plasma corticoid method following intravenous corticotrophin injection. As a consequence the dose level in quantitative assays of intravenously injected corticotrophin are, in our hands, of the same order as in the adrenal ascorbic acid depletion method.

scholarly journals Ratiometric Fluorescent Biosensors for Glucose and Lactate Using an Oxygen-Sensing Membrane

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 208
Author(s):  
Hong Dinh Duong ◽  
Jong Il Rhee
Keyword(s):  
Limit Of Detection ◽  
Oxygen Sensing ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Oxidation Reactions ◽  
Lactate Oxidase ◽  
Lactate Oxidation ◽  
Detection Range ◽  
Quenching Effect ◽  
Sensing Membrane

In this study, ratiometric fluorescent glucose and lactate biosensors were developed using a ratiometric fluorescent oxygen-sensing membrane immobilized with glucose oxidase (GOD) or lactate oxidase (LOX). Herein, the ratiometric fluorescent oxygen-sensing membrane was fabricated with the ratio of two emission wavelengths of platinum meso-tetra (pentafluorophenyl) porphyrin (PtP) doped in polystyrene particles and coumarin 6 (C6) captured into silica particles. The operation mechanism of the sensing membranes was based on (i) the fluorescence quenching effect of the PtP dye by oxygen molecules, and (ii) the consumption of oxygen levels in the glucose or lactate oxidation reactions under the catalysis of GOD or LOX. The ratiometric fluorescent glucose-sensing membrane showed high sensitivity to glucose in the range of 0.1–2 mM, with a limit of detection (LOD) of 0.031 mM, whereas the ratiometric fluorescent lactate-sensing membrane showed the linear detection range of 0.1–0.8 mM, with an LOD of 0.06 mM. These sensing membranes also showed good selectivity, fast reversibility, and stability over long-term use. They were applied to detect glucose and lactate in artificial human serum, and they provided reliable measurement results.

Impact of high temperature stress on ascorbic acid concentration in tomato

2018 ◽  
pp. 985-990
Author(s):  
V. Hernández ◽  
P. Hellín ◽  
J. Fenoll ◽  
M.V. Molina ◽  
I. Garrido ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
High Temperature ◽  
Temperature Stress ◽  
Acid Concentration ◽  
High Temperature Stress ◽  
Ascorbic Acid Concentration

scholarly journals Interference of ascorbic acid with chemical analytes

2005 ◽  
Vol 42 (6) ◽  
pp. 475-477 ◽  
Author(s):  
Qing H Meng ◽  
William C Irwin ◽  
Jennifer Fesser ◽  
K Lorne Massey
Keyword(s):  
Ascorbic Acid ◽  
Creatine Kinase ◽  
Uric Acid ◽  
Total Cholesterol ◽  
Acid Concentration ◽  
Total Bilirubin ◽  
Binding Capacity ◽  
Ascorbic Acid Concentration ◽  
Sodium Potassium ◽  
Creatine Kinase Mb

Background: Ascorbic acid can interfere with methodologies involving redox reactions, while comprehensive studies on main chemistry analysers have not been reported. We therefore attempted to determine the interference of ascorbic acid with analytes on the Beckman Synchron LX20®. Methods: Various concentrations of ascorbic acid were added to serum, and the serum analytes were measured on the LX20. Results: With a serum ascorbic acid concentration of 12.0 mmol/L, the values for sodium, potassium, calcium and creatinine increased by 43%, 58%, 103% and 26%, respectively ( P<0.01). With a serum ascorbic acid concentration of 12.0 mmol/L, the values for chloride, total bilirubin and uric acid decreased by 33%, 62% and 83%, respectively ( P<0.01), and were undetectable for total cholesterol, triglyceride, ammonia and lactate. There was no definite influence of ascorbic acid on analytical values for total CO2, urea, glucose, phosphate, total protein, albumin, amylase, creatine kinase, creatine kinase-MB, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total iron, unbound iron-binding capacity or magnesium. Conclusions: Ascorbic acid causes a false increase in sodium, potassium, calcium and creatinine results and a false decrease in chloride, total bilirubin, uric acid, total cholesterol, triglyceride, ammonia and lactate results.

Sign in / Sign up

Export Citation Format

Share Document