scholarly journals Hydrogel-Based Sensors for Ethanol Detection in Alcoholic Beverages

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1199 ◽  
Author(s):  
Jan Erfkamp ◽  
Margarita Guenther ◽  
Gerald Gerlach
Keyword(s):  
Ph Value ◽  
Limit Of Detection ◽  
Swelling Pressure ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Alcoholic Beverages ◽  
Reliable Determination ◽  
Piezoresistive Pressure Sensor ◽  
Alcohol Sensor

A fast and reliable determination of the ethanol concentration is essential in the analysis of alcoholic beverages. However, different factors like pH value or salt concentration can influence the ethanol measurement. Furthermore, analytical figures of merit for the alcohol sensor, such as limit of detection, sensitivity and measurement uncertainty, are necessary for the application. In this paper, a detailed sensor characterization of a novel sensor based on ethanol-sensitive poly acrylamide hydrogels will be presented. The resulting swelling pressure of the hydrogel was transformed via a piezoresistive pressure sensor into a measurable output voltage. These kinds of sensors can be used over a large measuring range, up to 50 vol% ethanol and more, with a high sensitivity. In the range from pH 7.4 to 4, the pH value had no influence on the sensor signal. Higher salt concentrations can slightly influence the measurement. The detection limit amounts to 0.06–0.65 vol% ethanol. The concentration of a vodka sample was determined with a sufficient measuring uncertainty.

scholarly journals ZnO Tips Dotted with Au Nanoparticles—Advanced SERS Determination of Trace Nicotine

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 465
Author(s):  
Jiaying Cao ◽  
Yan Zhai ◽  
Wanxin Tang ◽  
Xiaoyu Guo ◽  
Ying Wen ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Lung Damage ◽  
Sers Substrate ◽  
Detection Range ◽  
Reliable Determination ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Long-term exposure to nicotine causes a variety of human diseases, such as lung damage/adenocarcinoma, nausea and vomiting, headache, incontinence and heart failure. In this work, as a surface-enhanced Raman scattering (SERS) substrate, zinc oxide (ZnO) tips decorated with gold nanoparticles (AuNPs) are fabricated and designated as ZnO/Au. Taking advantage of the synergistic effect of a ZnO semiconductor with morphology of tips and AuNPs, the ZnO/Au-based SERS assay for nicotine demonstrates high sensitivity and the limit of detection 8.9 × 10−12 mol/L is reached, as well as the corresponding linear dynamic detection range of 10−10–10−6 mol/L. Additionally, the signal reproducibility offered by the SERS substrate could realize the reliable determination of trace nicotine in saliva.

scholarly journals Copper-nickel oxide nanofilm modified electrode for non-enzymatic determination of glucose

2020 ◽  
Vol 10 (3) ◽  
pp. 245-255
Author(s):  
Mahsa Hasanzadeh ◽  
Zahra Hasanzadeh ◽  
Sakineh Alizadeh ◽  
Mehran Sayadi ◽  
Mojtaba Nasiri Nezhad ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Stability Loss ◽  
The Novel ◽  
Step Potential ◽  
Enzymatic Determination ◽  
Wide Range ◽  
Naoh Solution

CuxO-NiO nanocomposite film for the non-enzymatic determination of glucose was prepared by the novel modifying method. At first, anodized Cu electrode was kept in a mixture solution of CuSO4, NiSO4 and H2SO4 for 15 minutes. Then, a cathodization process with a step potential of -6 V in a mixture solution of CuSO4 and NiSO4 was initiated, generating formation of porous Cu-Ni film on the bare Cu electrode by electrodeposition assisted by the release of hydrogen bubbles acting as soft templates. Optimized conditions were determined by the experimental design software for electrodeposition process. Afterward, Cu-Ni modified electrode was scanned by cyclic voltammetry (CV) method in NaOH solution to convert Cu and Ni nanoparticles to the nano-scaled CuxO-NiO film. The electrocatalytic behavior of the novel CuxO-NiO film toward glucose oxidation was studied by CV and chronoamperometry (CHA) techniques. The calibration curve of glucose was found linear in a wide range of 0.04–5.76 mM, with a low limit of detection (LOD) of 7.3 µM (S/N = 3) and high sensitivity (1.38 mA mM-1 cm-2). The sensor showed high selectivity against some usual interfering species and high stability (loss of only 6.3 % of its performance over one month). The prepared CuxO-NiO nanofilm based sensor was successfully applied for monitoring glucose in human blood serum and urine samples.

scholarly journals Determination of cyanide in bamboo shoots by microdiffusion combined with ion chromatography–pulsed amperometric detection

2018 ◽  
Vol 5 (4) ◽  
pp. 172128 ◽  
Author(s):  
Ming Ding ◽  
Kailiang Wang
Keyword(s):  
Ion Chromatography ◽  
Limit Of Detection ◽  
Correlation Coefficients ◽  
Amperometric Detection ◽  
High Sensitivity ◽  
Practical Method ◽  
Pulsed Amperometric Detection ◽  
Bamboo Shoots ◽  
Relative Standard

A practical method for the determination of cyanide in bamboo shoots has been developed using microdiffusion preparation integrated with ion chromatography–pulsed amperometric detection (IC-PAD). Cyanide was released from bamboo shoots after Conway cell microdiffusion, and then analysed by IC-PAD. In comparison with the previously reported methods, derivatization and ion-pairing agent addition were not required in this proposed microdiffusion combined with IC-PAD method. The microdiffusion parameters were optimized including hydrolysis systems, temperature, time, and so on. Under the optimum conditions, the linear range of the calibration curve for cyanide was 0.2–200.0 µg kg −1 with satisfactory correlation coefficients of 0.9996 and the limit of detection was 0.2 µg kg −1 ( S/N  = 3). The spiked recovery range was from 92.8 to 98.6%. The intra-day and inter-day relative standard deviations of cyanide were 2.7–14.9% and 3.0–18.3%, respectively. This method was proved to be convenient in operation with high sensitivity, precision and accuracy, and was successfully applied in the determination of cyanide in bamboo shoot samples.

scholarly journals Non-enzymatic sensor for determination of glucose based on PtNi nanoparticles decorated graphene

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Risheng Li ◽  
Xu Deng ◽  
Longfei Xia
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Glucose Detection ◽  
Serum Samples ◽  
Time Curve ◽  
Current Time ◽  
Glass Carbon ◽  
Graphene Glass ◽  
Ptni Alloy

Abstract Diabetes has become a universal epidemic in recent years. Herein, the monitoring of glucose in blood is of importance in clinical applications. In this work, PtNi alloy nanoparticles homogeneously dispersed on graphene (PtNi alloy-graphene) was synthesized as a highly effective electrode material for glucose detection. Based on the modified PtNi alloy-graphene/glass carbon (PtNi alloy-graphene/GC) electrode, it is found that the PtNi alloy-graphene/GC electrode exhibited excellent electrocatalytic performance on glucose oxidation. Furthermore, the results from amperometric current–time curve show a good linear range of 0.5–15 mM with the limit of detection of 16 uM (S/N = 3) and a high sensitivity of 24.03 uAmM−1 cm−2. On account of the good selectivity and durability, the modified electrode was successfully applied on glucose detection in blood serum samples.

Novel electrochemiluminescent materials for sensor applications

2014 ◽  
Vol 174 ◽  
pp. 357-367 ◽  
Author(s):  
Lynn Dennany ◽  
Zahera Mohsan ◽  
Alexander L. Kanibolotsky ◽  
Peter J. Skabara
Keyword(s):  
Redox Reactions ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Radical Cations ◽  
Detection Sensitivity ◽  
Sensor Development ◽  
Sensor Applications ◽  
Sensor Devices ◽  
The Impact

Electrochemiluminescence (ECL) uses redox reactions to generate light at an electrode surface, and is gaining increasing attention for biosensor development due to its high sensitivity and excellent signal-to-noise ratio. ECL studies of monodisperse oligofluorene–truxenes (T4 series) have been reported previously, showing the production of stable radical cations and radical anions, generating blue ECL. The compound in this study differs from the original structures, in that there are 2,1,3-benzothiadazole (BT) units inserted between the first and second fluorene units of the quarterfluorenyl arms. It was therefore anticipated that the incorporation of these highly luminescent and ECL-active compounds into sensor development would lead to significant decreases in detection limits. In this contribution, we report on the impact of incorporating these novel complexes into sensor devices on the ECL efficiency, as well as the ability of these to improve the detection sensitivity and decrease the limit of detection using the reagent-free detection of model analytes. The real world impact of these compounds is elucidated through the comparison with more standard ECL materials such as ruthenium-based compounds. The potential for multiple applications is to be examined within this contribution.

scholarly journals Diastereomeric ratio determination by high sensitivity band-selective pure shift NMR spectroscopy

2014 ◽  
Vol 50 (19) ◽  
pp. 2512-2514 ◽  
Author(s):  
Ralph W. Adams ◽  
Liam Byrne ◽  
Péter Király ◽  
Mohammadali Foroozandeh ◽  
Liladhar Paudel ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
High Sensitivity ◽  
Reliable Determination ◽  
Ratio Determination

Pure shift NMR using band-selective decoupling allows simpler and more reliable determination of diastereomeric ratio.

scholarly journals Determination of Methadone and Tramadol in Vitreous Humor Specimens Using Dispersive LiquidLiquidMicroextractionandUltraHighPerformance Liquid Chromatography

2021 ◽  
Vol 11 (1) ◽  
pp. 31530.1-31530.9
Author(s):  
Maryam Akhgari ◽  
Keyword(s):  
Liquid Chromatography ◽  
Ph Value ◽  
Limit Of Detection ◽  
Vitreous Humor ◽  
Point Of View ◽  
Limit Of Quantification ◽  
Ultrahigh Performance Liquid Chromatography ◽  
Abused Drugs ◽  
Dispersive Liquid Liquid Microextraction

Background: Drug abuse is spreading rapidly all over the world. Methadone and tramadol are among not only the most abused opioids but also important from the forensic point of view. Therefore, we need to devise a simple and sensitive method for the sample preparation and identification of abused drugs in postmortem specimens. Methods: A simple and rapid Dispersive Liquid-Liquid Microextraction (DLLME) technique coupled with Ultrahigh Performance Liquid Chromatography (UHPLC) was developed for the extraction and analysis of methadone and tramadol from postmortem vitreous humor samples. Different parameters affecting the extraction recovery, such as the type and volume of extraction and dispersion solvents, pH value, sensitivity, and specificity, were optimized and studied. Results: Under optimized conditions, the recovery ranges were 82.3%-89.6% and 85.4%-87.1% for methadone and tramadol, respectively. The linear range was 25-100 ng/mL for both methadone and tramadol with a correlation coefficient (R2) of more than 0.98. Limit of Detection (LoD) and Limit of Quantification (LoQ) were 3 and 8 ng/mL for methadone and 6 and 16 ng/mL for tramadol. The accuracy level of the methods for methadone and tramadol detection were 99.4%-100% and 99.7%-99.9%, respectively. The method was specific enough for the qualitative and quantitative determination of methadone and tramadol. Conclusion: The obtained results showed that DLLME combined with UHPLC is a fast and straightforward method for determining methadone and tramadol in postmortem vitreous humor specimens.

scholarly journals Validation of the TSH IRMA Kit for Determination of the TSH Levels in Human Blood Serum

2018 ◽  
Vol 3 (3) ◽  
pp. 126
Author(s):  
Gina Mondrida ◽  
Sutari Sutari ◽  
Triningsih Triningsih ◽  
Sri Setyowati ◽  
V. Yulianti S ◽  
...  
Keyword(s):  
Blood Serum ◽  
Human Blood ◽  
Limit Of Detection ◽  
Specific Binding ◽  
Thyroid Stimulating Hormone ◽  
The Body ◽  
Human Blood Serum ◽  
Detection Sensitivity ◽  
Assay Precision

<p>TSH IRMA kit is a kit used for the determination of TSH (Thyroid Stimulating Hormone) levels in human blood serum. Thyroid hormone is a hormone that our bodies need for growth of the brain, bone and other tissues and regulate the metabolism in the body.<strong> </strong>TSH normal range for adult is in the range of 0.4-4.5 mIU/L, whereas for baby is about 3.0-18.0 mIU/L. Thyroid would affect the quality of optimal growth of children if disturbed. Therefore, TSH assay in the blood needs to be determined to know whether the function of the thyroid gland works normally or not. Detection of TSH in blood can be performed by Immunoradiometricassay (IRMA) method. IRMA method is one of the immunoassay techniques based on immunological reactions (antigen-antibody binding) using radionuclide <sup>125</sup>I as a tracer, that sample in small quantity can be detected.<em> </em> IRMA method was developed locally by replacing TSH IRMA kit which is costly since imported from commercial companies. Center for Radioisotope and Radiopharmaceutical Technology (PTRR) BATAN has successfully developed the TSH IRMA kit that can be used to determine the levels of TSH in human blood. TSH IRMA kit must be validated to know the limit of detection, sensitivity, accuracy, precision and the assay parameters, such as Non-Specific Binding (NSB) and Maximum Binding (MB). Validation of TSH IRMA kit had been carried out resulting in the limit of detection of 0.115 ng/mL, accuracy with a recovery of 93.6-108.0 %, intra-assay precision (% CV) QC L = 1.9848, QC M = 3.6360 % and QC H = 2.2085 % while the inter-assay precision (% CV) QC L = 11.0055, QC M = 5.6768 %  and  QC H = 5.4181 %.  It was concluded that this TSH IRMA kit showed good performance based on the % NSB and % B/T of 0.68 and 34.64 %, respectively.</p>

scholarly journals Determination of fumonisins B1 and B2 in beer

2011 ◽  
Vol 23 (No. 1) ◽  
pp. 20-26 ◽  
Author(s):  
Ľ. Daško ◽  
D. Rauová ◽  
E. Belajová ◽  
M. Kováč
Keyword(s):  
Fluorescence Detection ◽  
Phosphate Buffer ◽  
Analytical Procedure ◽  
Ph Value ◽  
Limit Of Detection ◽  
Gradient Elution ◽  
Cleaning Procedure ◽  
Peak Splitting

The aim of this study was to investigate the contamination of beer of Slovak origin with fumonisins. A suitable analytical procedure was suggested &ndash; the limit of detection at the level close to 1 &micro;g/l was achieved for both fumonisins B<sub>1</sub> and B<sub>2</sub>. The recovery was determined at 93% for fumonisin B<sub>1 </sub>and at 78% for fumonisin B<sub>2</sub>. Fluorescence detection was used after derivatisation with a mixture of o-phthaldialdehyde and 2-mercaptoethanol. Phosphate buffer usually applied resulted in a poor separation of derivatised fumonisins. Peak splitting was observed depending on the pH of the eluent. The pH value of 2.6 was found suitable for the peak splitting elimination. A convenient gradient elution metod was suggested avoiding the possible interference in fumonisin contents determination. For the preparation of samples, immunoaffinity cleaning procedure was applied. Beer samples from all domestic producers were analysed. The content of fumonisins determined was under the limit of detection in all cases. All the beers tested were produced from the barley grown in 2003. &nbsp;

MLD Method for the Determination of Major Components in MgO-Cr Refractory Products

2016 ◽  
Vol 680 ◽  
pp. 76-81
Author(s):  
Juan Juan Lu ◽  
Yu Bing Liu ◽  
Jian Xing Ren ◽  
Wei Han
Keyword(s):  
Refractory Material ◽  
Calibration Curve ◽  
High Sensitivity ◽  
Technical Difficulty ◽  
Detection Sensitivity ◽  
Dilution Ratio ◽  
Novel Approach ◽  
Accuracy And Precision ◽  
Main Components

In this paper a novel approach is presented for determination of the main components in MgO-Cr refractory material. With the approach, the intensity conversion of fused sample at different dilution ratios can be obtained by establishing the correlation between elements’ intensity and dilution ratio. MgO-Cr refractory material is fused hardly and the dilution ratio requires more than 20 in XRF analysis. Nevertheless, high dilution can reduce the detection sensitivity of low content elements. Using the technology of intensity conversion at different dilution ratio in this paper, a calibration curve was obtained with different dilution ratios. In this method, we obtained a calibration curve successfully and got the satisfactory results for MgO-Cr refractory which was fused well. The new method suggests consistent accuracy and precision with standard method, and it can also simplify the preparation process of samples. The approach shows high sensitivity, good accuracy and precision, meanwhile, it reduces the technical difficulty and labor intensity greatly in analysis method.

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