scholarly journals A Simple and Sensitive Optode Sensor Glucose Based on Immobilization Benedict Into Nata Cellulose Membranes

2020 ◽  
Vol 15 (4) ◽  
pp. 404
Author(s):  
Dhony Hermanto ◽  
Rochmad Kris Sanjaya ◽  
Nurul Ismillayli
Keyword(s):  
Optimum Condition ◽  
Optical Sensor ◽  
Chemical Sensor ◽  
Limit Of Detection ◽  
Glucose Determination ◽  
Sensor Glucose ◽  
Supporting Material ◽  
Cellulose Membranes

Determination of glucose concentration in urine and blood that anyone can use at any time is Benedict reagent based chemical sensor. This optical sensor was developed by immobilizing Benedict reagent into nata cellulose as supporting material via entrapment. The nata cellulose/Benedict membrane for glucose determination has optimum condition at maximum wavelenght   of 541.57 nm, Benedict concentration of 0.4470 M, and ratio of nata cellulse mass to Benedict volume was 1:3. Characterization of optical sensor for glucose was in working range of 0-5000 ppm, limit of detection was 911,11 ppm, sensitivity was 0.0009 and reproducibility was 0.2295%.

Preparation and characterization of a novel tetrakis(4-hydroxyphenyl)porphyrin–graphene oxide nanocomposite and application in an optical sensor and determination of mercury ions

RSC Advances ◽  
2015 ◽  
Vol 5 (113) ◽  
pp. 93310-93317 ◽  
Author(s):  
Rouholah Zare-Dorabei ◽  
Rahmatollah Rahimi ◽  
Asgar Koohi ◽  
Solmaz Zargari
Keyword(s):  
Graphene Oxide ◽  
Optical Sensor ◽  
Chemical Sensor ◽  
Mercury Ions ◽  
Optical Chemical Sensor

Optical chemical sensor for determination of mercury ions.

scholarly journals Synthesis and characterization of a ZnMn2O4nanostructure as a chemical nanosensor: a facile and new approach for colorimetric determination of omeprazole and lansoprazole drugs

RSC Advances ◽  
2017 ◽  
Vol 7 (69) ◽  
pp. 43798-43811 ◽  
Author(s):  
Mostafa Y. Nassar ◽  
Eman A. El-Moety ◽  
M. F. El-Shahat
Keyword(s):  
Chemical Sensor ◽  
Combustion Method ◽  
Synthesis And Characterization ◽  
Colorimetric Determination ◽  
New Approach ◽  
Auto Combustion

ZnMn2O4nanostructure was preparedviaan auto-combustion method using different fuels, and it was used as a chemical sensor for determination of omeprazole and lansoprazole drugs.

scholarly journals Characterization of handmade Nepali paper as a platform for paper analytical device to determine anti-diabetic drug

2021 ◽  
Author(s):  
Ram Bhattarai ◽  
Sanam Pudasaini ◽  
Mukesh Sah ◽  
Bhanu Neupane ◽  
Basant Giri
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Water Contact ◽  
Regulatory Standards ◽  
Three Samples ◽  
Limit Of Quantitation ◽  
Metformin Concentration ◽  
Analytical Device

The COVID-19 pandemic has highlighted the need of eco-friendly and locally or distributed manufacturing of diagnostic and safety products. Here, we characterized five handmade papers for their potential application to make paper analytical device (PADs). The handmade papers were made from locally available plant fiber using eco-friendly method. Thickness, grammage, and apparent density of the paper samples ranged from 198 μm to 314 μm, 49 g/m2 to 117.8 g/m2, and 0.23 to 0.39 g/cm3, respectively. Moisture content, water filtration and wicking speed ranged from 5.2% to 7.1%, 35.7 to 156.7, and 0.062 to 0.124 mms-1, respectively. Further, water contact angle and porosity ranged from 76˚ to 112˚ and 79% to 83%, respectively. The best paper sample one was chosen to fabricate PADs which were used for the determination of metformin. The metformin assay on PADs followed linear range from 0.0625 to 0.5 mg/mL. The assay had limit of detection and limit of quantitation of 0.05 mg/mL and 0.18 mg/mL respectively. The new method was used to test metformin samples (n=20) collected from local pharmacies. The average amount of metformin concentration in samples was 465.6 ± 15.1mg/tablet. Three samples did not meet the regulatory standards. When compared with spectrophotometric method, PADs assay correctly predicted 18 out of 20 samples. The PADs assay on handmade paper may provide a low-cost and easy-to-use system to screening the quality of drugs and other point-of-need applications.

Optimization of a doped sol–gel glass with a nanoporous structure as a chemical sensor for the determination of cobalt(ii): analysis of food, pharmaceutical and biological samples

2020 ◽  
Vol 44 (34) ◽  
pp. 14358-14366
Author(s):  
Masood Zarei poor ◽  
Vida Rezaei
Keyword(s):  
Optical Sensor ◽  
Biological Samples ◽  
Chemical Sensor ◽  
Sol Gel ◽  
Nanoporous Structure

A PAN incorporated sol–gel glass with a nanoporous structure as an optical sensor for the detection of Co(ii).

scholarly journals Determination of hydroquinone in a square wave voltammetry procedure using a graphite-polyurethane composite electrode

2006 ◽  
Vol 31 (4) ◽  
pp. 59-62 ◽  
Author(s):  
P. Cervini ◽  
E.T.G. Cavalheiro
Keyword(s):  
Confidence Level ◽  
Square Wave Voltammetry ◽  
Composite Electrode ◽  
Limit Of Detection ◽  
Voltammetric Sensor ◽  
Square Wave ◽  
Polyurethane Composite ◽  
Wave Voltammetry

In order to a better characterization of a graphite-polyurethane composite intended to be used as a voltammetric sensor, the performance in a square wave voltammetric procedure was investigated. Using hydroquinone (HQ) as a probe, the electrode showed to be useful in square wave voltammetry with limit of detection of 0.28 µmol L-1, with recoveries between 99.1 and 101.5%. The results of the proposed method agreed with HPLC ones within 95% confidence level.

scholarly journals A novel optode sensor for the determination of palladium(II) in water and a hydrogenation catalyst

2009 ◽  
Vol 74 (3) ◽  
pp. 311-315 ◽  
Author(s):  
Hossein Tavallali ◽  
Pisheh Jahromi
Keyword(s):  
Response Time ◽  
Aqueous Solutions ◽  
Optical Sensor ◽  
Color Change ◽  
Limit Of Detection ◽  
Linear Range ◽  
Hydrogenation Catalyst ◽  
Catalyst Sample ◽  
Dynamic Linear Range

A novel optical sensor was established to determine palladium(II) based on the immobilization of 1-(2-pyridylazo)-2-naphthol (PAN) on a triacetylcellulose membrane. Palladium ions react with the immobilized PAN and cause a decrease in the absorbance of the membrane at 469 nm. The response time of the optode was 8-10 min depending on the concentration of Pd(II) ions. This sensing phase had a dynamic linear range of 0.10-12.0 ?g ml-1 palladium ions with a limit of detection of 65 ng ml-1. The sensor can readily be regenerated using an ethylenediamine solution. The sensor could be fully regenerated, and the color change was fully reversible. The method was successfully applied for the determination of Pd(II) in synthetic aqueous solutions and in a hydrogenation catalyst sample.

scholarly journals Dispersed Conducting Polymer Nanocomposites with Glucose Oxidase and Gold Nanoparticles for the Design of Enzymatic Glucose Biosensors

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2173
Author(s):  
Natalija German ◽  
Almira Ramanaviciene ◽  
Arunas Ramanavicius
Keyword(s):  
Glucose Oxidase ◽  
Conducting Polymer ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Serum Samples ◽  
Glucose Determination ◽  
Constant Potential ◽  
Good Repeatability ◽  
Graphite Rod

Biosensors for the determination of glucose concentration have a great significance in clinical diagnosis, and in the food and pharmaceutics industries. In this research, short-chain polyaniline (PANI) and polypyrrole (Ppy)-based nanocomposites with glucose oxidase (GOx) and 6 nm diameter AuNPs (AuNPs(6 nm)) were deposited on the graphite rod (GR) electrode followed by the immobilization of GOx. Optimal conditions for the modification of GR electrodes by conducting polymer-based nanocomposites and GOx were elaborated. The electrodes were investigated by cyclic voltammetry and constant potential amperometry in the presence of the redox mediator phenazine methosulfate (PMS). The improved enzymatic biosensors based on GR/PANI-AuNPs(6 nm)-GOx/GOx and GR/Ppy-AuNPs(6 nm)-GOx/GOx electrodes were characterized by high sensitivity (65.4 and 55.4 μA mM−1 cm−2), low limit of detection (0.070 and 0.071 mmol L−1), wide linear range (up to 16.5 mmol L−1), good repeatability (RSD 4.67 and 5.89%), and appropriate stability (half-life period (τ1/2) was 22 and 17 days, respectively). The excellent anti-interference ability to ascorbic and uric acids and successful practical application for glucose determination in serum samples was presented for GR/PANI-AuNPs(6 nm)-GOx/GOx electrode.

scholarly journals Determination of Atorvastatin with Voltammetric Sensors Based on Nanomaterials

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 57
Author(s):  
Ramona Oana Gunache (Roșca) ◽  
Alexandra Virginia Bounegru ◽  
Constantin Apetrei
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Products ◽  
Spectrometric Method ◽  
Background Current ◽  
Limit Of Quantification ◽  
Voltammetric Sensors ◽  
Printed Sensors ◽  
Lower Background

This paper presents an accurate and fast electrochemical method for atorvastatin determination in pharmaceutical products. Two screen-printed sensors, one—carbon based (SPCE) and one based on carbon nanotubes and gold nanoparticles (AuNP-CNT/SPCE) were used during the electrochemical analyses. At all experimental stages, cyclic voltammetry was employed, both for the characterization of the sensors and their electrochemical behavior, and for quantitative determinations. AuNP-CNT/SPCE has showed an extended active area, higher intensity peaks, better reversibility and lower background current than the unmodified sensor. For atorvastatin quantification, a calibration curve has been developed within the 1.2–606.25 µM concentration range. A linearity relation between the current of the anodic peak and concentration has been obtained in the range 1.2–53.33 µMfor both sensors. With the AuNP-CNT/SPCE sensor, low values of limit of detection, LOD (1.92 × 10−7 M) and limit of quantification, LOQ (6.39 × 10−7 M) have been obtained, which demonstrates the feasibility of the method of determining atorvastatin from real samples. Atorvastatin amount has been successfully determined from pharmaceutical products using AuNP-CNT/SPCE. The results were similar to the manufacturer’s specifications regarding the dosage per tablet and to the concentrations obtained by applying the FTIR spectrometric method.

scholarly journals CdSe/ZnS Quantum Dots As a Fluorescence Probes For Determination of Vitamin B1

2021 ◽  
Author(s):  
Reza Tirbandpaya ◽  
Abdolraouf Samadi-Maybodi
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Vitamin B1 ◽  
Fluorescence Probes ◽  
Fast Method ◽  
Excitonic Absorption ◽  
Wet Chemical ◽  
Excitonic Absorption Peak

Abstract This paper presents a new and fast method for determination of vitamin B1 (thiamine) using functionalized CdSe/ZnS quantum dots (QDs) as a sensor. In this study the core-shell CdSe/ZnS QDs with thioglycolic acid capping agents were synthesized by wet chemical method in aqueous solution. Electronic absorption was applied for size determination of the QDs, the average diameters of the synthesized quantum dots were calculated using wavelength of the first excitonic absorption peak. The methods of FESEM and FTIR were also used for characterization of the prepared samples. The results indicated that vitamin B1 could effectively quench the QDs emission and the fluorescence intensity decreased linearly with the concentration of vitamin B1 ranging from 10-7 to 10-4 molL−1 with limit of detection of 2×10-8 mol L−1. Determination of vitamin B1in pills from two pharmaceutical companies were used as real samples using this method .

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