scholarly journals Determination of Uric Acid in Artificial Saliva with Compact AMP3291 Reader and Au Nanoparticles Modified Electrode

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 73
Author(s):  
Jessica Piedras ◽  
Rocio B. Dominguez ◽  
Juan Manuel Gutiérrez

Uric acid (UA) is a residual product of purines in the body and has been proposed as a valuable biomarker for Diabetes Mellitus, renal disorder, hypertension and preeclampsia. This work presents a sensing platform for nonenzymatic UA detection using a screen-printed electrode modified with gold nanoparticles (SPE-AuNps) operated with the compact and low-cost amperometric reader AMP3291. This laboratory-made instrument was designed using the analog front end LMP91000 and the microcontroller ESP32; the operational parameters like working potential, acquisition time and dynamic measuring range were configured for UA detection. The whole sensing system (AMP3291+ SPE-AuNps) was evaluated for nonenzymatic sensing of UA, showing a fast response time of 3.5 s, a sensitivity of 0.022 μA·μM−1, a linear range from 20 to 200 μM (R2 = 0.993) and a limit of detection of 11.91 μM. Throughout, a piece of commercial equipment was used for validation and noticeably the measurements with the AMP3291-based platform showed improved performance, indicating the feasibility of the developed instrument for UA monitoring and potentially for in situ decentralized applications. Finally, artificial saliva was used as model medium exhibiting interesting analytical parameters, encouraging to consider the reported system as a potentially valuable tool for monitoring UA for clinical applications in resource-limited settings.

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8255
Author(s):  
Emiliano Zampetti ◽  
Paolo Papa ◽  
Andrea Bearzotti ◽  
Antonella Macagnano

In environments polluted by mercury vapors that are potentially harmful to human health, there is a need to perform rapid surveys in order to promptly identify the sources of emission. With this aim, in this work, a low cost, pocket-sized portable mercury measurement system, with a fast response signal is presented. It consists of a preconcentrator, able to adsorb and subsequently release the mercury vapour detected by a quartz crystal microbalance (QCM) sensor. The preconcentrator is based on an adsorbing layer of titania/gold nanoparticles (TiO2NP/AuNPs), deposited on a micro-heater that acts as mercury thermal desorption. For the detection of the released mercury vapour, gold electrodes QCM (20 MHz) have been used. The experimental results, performed in simulated polluted mercury-vapour environments, showed a detection capability with a prompt response. In particular, frequency shifts (−118 Hz ± 2 Hz and −30 Hz ± 2 Hz) were detected at concentrations of 65 µg/m3 Hg0 and 30 µg/m3 Hg0, with sampling times of 60 min and 30 min, respectively. A system limit of detection (LOD) of 5 µg/m3 was evaluated for the 30 min sampling time.


Lontara ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 41-50
Author(s):  
Usman Umar ◽  
Risnawaty Alyah

Gout or gout arthritis is a disease caused by the accumulation of monosodium uric crystals in the body. Uric acid is the result of the final metabolism of purines, which is a component of nucleic acids found in the body's cell nucleus. Increased uric acid can cause disturbances in the human body such as feelings of pain. The standard system used to measure uric acid levels in the blood, in general, is an invasive system that uses blood samples and is performed in clinics, health centers, and hospitals at a high cost. This research aims to develop a non-invasive system measuring gout using Near Infrared (NIR) sensor with 940 nm LED and Photodiode as a detector at a wavelength range of 600-1300 nm. The method of developing this tool begins with the stages, conducting a literature study resulting in tool design and tool making as well as tool validation by comparing invasive and non-invasive techniques. The results of this study produce a simple gout monitoring tool with an error value of 4% and low cost and easy to use. Analysis of the results of the tests using analysis of variance P-value> 0.05 and the t-test P (T <= t) 0.45> α shows that the tool designed can be used to monitor gout.


2021 ◽  
Author(s):  
Ramesh Lal ◽  
Bhajan Lal Bhattia ◽  
Ali M. Alsalme ◽  
Asma A. Al-Othman ◽  
Ayman Nafady ◽  
...  

Abstract The gout is mainly found due to accumulation of uric acid crystals into the joints which produces the inflammatory symptoms. Thus, it is highly demanded to detect uric acid from our body. Herein, we used wet chemical method for the preparation of composite material of cobalt oxide (Co3O4) with hydroxide functionalized multi-walled carbon nanotubes (MWCNTs). The analytical techniques such as scanning electron microscopy (SEM), powder X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and Infra-red spectroscopy (FTIR) were used to characterize the composite material. The Co3O4 exhibits a dendrite morphology and very well chemically coupled with MWCNTs. The elemental analysis confirmed the presence of Co, O and C as main constituent of the composite material. The Co3O4 exhibits a cubic unit cell crystallography in the composite system. The FTIR study has revealed the characteristic bands of Co-O bands in the composite material. The cyclic voltammetry was used to study the electrochemical properties of prepared materials. The composite sample with highest percentage of MWCNTs showed an excellent electrochemical activity towards the oxidation of uric acid in phosphate buffer solution pH 7.3. The enzyme free uric acid sensor possessed a linear range of 0.1 mM to 3 mM with a quantified limit of detection of 0.005 mM. The modified electrode is stable, selective, and very sensitive towards uric acid, therefore it may be used for the monitoring of uric acid from clinical samples. The proposed composite material is low cost, and earth abundant, thus it can be of great interest for energy and biomedical fields.


Author(s):  
Khvorova L.S. ◽  
Byzov V.A.

The article is devoted to the creation of a carbohydrate product with rosehip extract in the form of sweets (glucose Fudge) with a therapeutic and preventive effect aimed at restoring the body of people exposed to intense physical and mental stress and the effects of damaging environmental factors. As carbohydrates in the recipe, simple carbohydrates (glucose) and complex carbohydrates in the form of starch molasses containing (maltose, tri - Tetra - sugars, dextrins) are used. Glucose in the formulation is the main energy ingredient, sweetener and structure-forming component that gives the product a solid consistency due to crystallization. The medicinal effect of the product is provided by rosehip extract. Numerous published studies have established its vitamin, immunostimulating and antioxidant activity, inhibition of uric acid formation and obesity, which are associated with flavonoids, other phenolic compounds, and vitamins. The list of medicinal properties of rosehip extract shows the feasibility of using it in additional nutrition of people in order to prevent diseases. For the formulation of our sweets, the extraction of crushed rosehip fruits was carried out three times with hot water at a temperature of 65-700C, followed by concentration of the extract under vacuum to 25-30% SV. The resulting extract-concentrate was introduced into the formulation in a dosage of 5.5% SV per 100 g of SV glucose Fudge, which provided the necessary dosage for the product when used from 3 (for children) to 10 sweets a day (for adults) for the prevention of colds.


2017 ◽  
Vol 68 (4) ◽  
pp. 666-670 ◽  
Author(s):  
Mirela Mihon ◽  
Catalin Stelian Tuta ◽  
Alina Catrinel Ion ◽  
Dana Niculae ◽  
Vasile Lavric

The aim of this work was the development and validation of a fast analytical method to determine the residual solvents content in radiopharmaceuticals such as: 18F-Fluorodeoxyglucose (18F-FDG), 18F-Fluoroestradiol (18F-FES), 18F-Fluorothymidine (18F-FLT),18F-Fluoromisonidazole (18F-FMISO). Radiopharmaceuticals are radioactive preparations for medical purposes used in nuclear medicine as tracers in diagnostic imaging and treatment of certain diseases. Positron Emission Tomography (PET) is a medical imaging technique that consists in introducing into the body of a small amount of a biologically active chemical compound labelled with a short lived positron-emitting radioisotope (18F, 11C, 68Ga). Residual solvents are critical impurities in radiopharmaceuticals that can affect labelling, stability and physicochemical properties of drugs. Therefore, the determination of these solvents is essential for quality control of radiopharmaceuticals. Validation of the control method for residual solvents by gas chromatography is referred by the European Pharmacopoeia using a special injection technique (head space). The parameters of the method, which comply with International Conference on Harmonization guidelines, are: accuracy, precision, linearity, limit of detection, limit of quantification and robustness. The proposed method (direct gas chromatography injection) proved to be linear, precise, accurate and robust. Good linearity was achieved for all the solvents and correlation coefficients (R2) for each residual solvent were found more than 0.99.


2019 ◽  
Vol 22 (7) ◽  
pp. 496-501
Author(s):  
Fatemeh Ahmadi-Motamayel ◽  
Parisa Falsafi ◽  
Hamidreza Abolsamadi ◽  
Mohammad T. Goodarzi ◽  
Jalal Poorolajal

Background: Cigarette smoke free radicals can cause cellular damage and different diseases. All the body fluids have antioxidants which protect against free radicals. Objective: The aim of this study was to evaluate salivary total antioxidant capacity and peroxidase, uric acid and malondialdehyde levels in smokers and a nonsmoking control group. Methods: Unstimulated saliva was collected from 510 males. A total of 259 subjects were current smokers and 251 were non-smokers. The levels of salivary total antioxidant capacity, uric acid, peroxidase and malondialdehyde were measured using standard procedures. Data were analyzed with t test and ANOVA. Results: The smokers were younger and dental hygiene index was higher than healthy nonsmoking controls. The mean total antioxidant capacity in smokers and nonsmokers was 0.13±0.07 and 0.21±011, respectively (P=0.001). Smokers had significantly lower peroxidase and uric acid levels than healthy controls. In addition, the mean malondialdehyde levels in the smokers and nonsmokers were 4.55 ±2.61 and 2.79 ±2.21, respectively (P=0.001). Conclusion: Cigarette smoke produces free radical and oxidative stress, causing many side effects. Salivary antioxidant levels decreased and malondialdehyde levels increased in smokers, indicating the high oxidative stress among smokers compared to nonsmokers. Cigarette smoke had deleterious effects on main salivary antioxidants levels.


2019 ◽  
Vol 15 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Quan-Bo Zhang ◽  
Dan Zhu ◽  
Zhong Wen ◽  
Ting Yi ◽  
Qing Li ◽  
...  

Objective: To investigate the changes of serum Uric Acid (sUA), lipids and Cystatin C (CysC) in primary gout patients, and to explore the clinical significance in gout patients. Methods: : sUA, CysC, high-sensitivity C-reactive Protein (hsCRP) and other biochemical parameters were measured in 326 gout patient and 210 healthy control subjects, blood cell counts were also detected. Clinical data were collected from gout patients. Results: sUA, CysC, hsCRP, Body Mass Index (BMI), White Blood Cell (WBC) counts, neutrophil Granulocyte (GR), Monocyte (Mo), Triglycerides (TG), plasma Total Cholesterol (TC), Very Low Density Lipoprotein (VLDL), apolipoprotein B100 (apoB100), Blood Glucose (GLU), serum Creatinine (sCr) and Urea Nitrogen (BUN) were significantly increased in gout patients compared with HC subjects (P<0.01, respectively), while lymphocyte counts and High Density Lipoprotein- Cholesterol (HDL-C) were significantly decreased in gout patients compared with HC subjects (P<0.01, respectively). Positive correlations were observed between concentration of sUA and age, TG, VLDL, sCr and CysC (P<0.05, respectively). While negative correlations were observed between the concentration of sUA and HDL-C(P<0.01). Besides, Positive correlations were observed between concentration of CysC and WBC, GR, Mo, apoA1, GLU, sCr, BUN, sUA, hsCRP (P<0.05, respectively). While negative correlations were observed between the concentration of CysC and TC, LDL-C(P<0.01, respectively). Conclusions: Blood lipid profile changes in gout patients. Gout patients who suffer from lipid metabolism disorder and vascular diseases might be associated with hyperuricemia, which leads to endothelial cell damage and vascular smooth muscle cell proliferation. CysC might be a marker for renal function damage and inflammation. Hyperuricemia is the risk factor of renal disorder in gout patients.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guanhua Xun ◽  
Stephan Thomas Lane ◽  
Vassily Andrew Petrov ◽  
Brandon Elliott Pepa ◽  
Huimin Zhao

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.


Biosensors ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Donggee Rho ◽  
Seunghyun Kim

An optical cavity-based biosensor (OCB) has been developed for point-of-care (POC) applications. This label-free biosensor employs low-cost components and simple fabrication processes to lower the overall cost while achieving high sensitivity using a differential detection method. To experimentally demonstrate its limit of detection (LOD), we conducted biosensing experiments with streptavidin and C-reactive protein (CRP). The optical cavity structure was optimized further for better sensitivity and easier fluid control. We utilized the polymer swelling property to fine-tune the optical cavity width, which significantly improved the success rate to produce measurable samples. Four different concentrations of streptavidin were tested in triplicate, and the LOD of the OCB was determined to be 1.35 nM. The OCB also successfully detected three different concentrations of human CRP using biotinylated CRP antibody. The LOD for CRP detection was 377 pM. All measurements were done using a small sample volume of 15 µL within 30 min. By reducing the sensing area, improving the functionalization and passivation processes, and increasing the sample volume, the LOD of the OCB are estimated to be reduced further to the femto-molar range. Overall, the demonstrated capability of the OCB in the present work shows great potential to be used as a promising POC biosensor.


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