Selective Electrode Research Articles

Wearable Electrochemical Sensor for Sweat-Based Potassium Ion and Glucose Detection in Exercise Health Monitoring.

The increasing prevalence of wearable devices has sparked a growing interest in real-time health monitoring and physiological parameter tracking. This study focuses on the development of a cost-effective sweat analysis device, utilizing microfluidic technology and selective electrochemical electrodes for non-invasive monitoring of glucose and potassium ions. The device, through real-time monitoring of glucose and potassium ion levels in sweat during physical activity, issues a warning signal when reaching experimentally set thresholds (K+ concentration at 7.5 mM, glucose concentrations at 60 μM and 120 μM). This alerts users to potential dehydration and hypoglycemic conditions. Through the integration of microfluidic devices and precise electrochemical analysis techniques, the device enables accurate and real-time monitoring of glucose and potassium ions in sweat. This advancement in wearable technology holds significant potential for personalized health management and preventive care, promoting overall well-being, and optimizing performance during physical activities.

A rational study of transduction mechanisms of different materials for all solid contact-ISEs

The new era of solid contact ion selective electrodes (SC-ISEs) miniaturized design has received an extensive amount of concern. Because it eliminated the requirement for ongoing internal solution composition optimization and created a two-phase system with stronger detection limitations. Herein, the determination of venlafaxine HCl is based on a comparison study between different ion- to electron transduction materials (such as; multiwalled carbon nanotubes (MWCNTs), polyaniline (PANi), and ferrocene) and illustrating their mechanisms in their applied sensors. Their different electrochemical features (such as bulk resistance (Rb**), double-layer capacitance (Cdl), geometric capacitance (Cg), and specific capacitance (Cp)) were evaluated and discussed by using the Electrochemical Impedance Spectroscopy (EIS), Chronopotentiometry (CP), and Cyclic Voltammetry (CV) experiments. The results indicated that each transducer's influence on the proposed sensor's electrochemical characteristics is determined by their unique chemical and physical properties. The electrochemical features vary for different solid contact materials used in transduction mechanisms. The results confirm that the MWCNT sensor revealed the best electrochemical behavior with the potentiometric response of a near-Nernestian slope of 56.1 ± 0.8 mV/decade with detection limits of 3.8 × 10−6 mol/L (r2 = 0.999) and a low potential drift (∆E/∆t) of 34.6 µV/s. Also, the selectivity study was performed in the presence of different interfering species either in single or complex matrices. This demonstrates excellent selectivity, stability, conductivity, and reliability as a VEN-TPB ion pair sensor for accurately measuring VEN in its various formulations. The proposed method was compared to HPLC reported technique and confirmed no significant difference between them. So, the proposed sensors fulfill their solutions' demand features for VEN appraisal.

Fabrication of a new magnesiun-ion selective electrode (Mg-ISE) based on photopolymer of poly(Tetrahydrofurfuryl Acrylate)(pTHFA) thin-films

This study has succeeded in fabricating Magnesium-ion selective electrode (Mg-ISE) using membrane poly (Tetrahydrofurfuryl acrylate) (pTHFA) synthesized by photopolymer technique. In this study, several experiments have been carried out which included optimization of pTHFA composition, performance testing of the Mg-ISE sensor, selectivity testing, pH effects and validation using real samples. Validation testing has been done by comparing the test results of the Mg-ISE sensor with the standard method using titration techniques. In the optimization study, the optimum composition of 1:1 mol ratio (KTpClPB/Ionophore) was obtained, where the KTpClPB used was 1 mg while the Ionophore used was Magnesium Ionophore III. The resulting Nernstian number is 26.9 mV/decade with a linear range of 0.1–10−6 M. Meanwhile, the resulting limit of detection (LoD) x[is]x was found to be 7.6 × 10−7 M. The Mg-ISE sensor also shows good selectivity with several ions, except with Ca2+-ion. In addition, the sensor can also work well for 9 weeks with an operating range at pH 4–9.

Construction of Dopamine Hydrochloride Liquid Selective Electrodes

Three liquid selective electrodes were synthesized based on particle pair to selective dopamine chloride. The construction electrodes consist of phosphomolybdicacid (dopamine), di-n-butyl phosphate, Di-n-butyl phthalate, and di-octylphenyl phosphonate as plasticizers materials. The construction of preparing probes was examined potentially with successes Nernstain response around 52.50 and 50. 50 mV/decade for electrodes on both DBPH and DOPH were as plasticizers, respectively. The most direct ranges concentrations of dopamine in drug form were found to be around 2.5×10-5-1.0×10-2 for DBPH and 4.30×10-5 -1.0×10-1 M for DOPH. The detection limits were reached to 2.31×10-6 in DBPH and 5. 63×10-6 M in DOPH electrode type. While third electrode relied on di-n-butyl phosphate (DPH), a non-Nernstain equivalent of around 19.10 mV/decade with a range of concentration about 2.2×10-5 -1.0×10-1 with a detection limit equivalent to 6.35×10-6. The pH values in the experimental application were asses to obtain the best determination of dopamine concentration at 10-3M. The optimisation of both electrodes DBPH and DOPH achieved good agreements to lifetime, selectivity, potentiometric techniques and accuracy of measurements. At the same time the standard expansion, various standard expansions and potentiometric titration result in an immediate strategy for the assurance of dopamine in drug form.

Effects of combination of tramadol and sildenafil citrate (Viagra) on hepatic and renal function parameters in Male Albino Rats

Erectile dysfunction, premature ejaculation and pleasure seeking have increased the use of sildenafil citrate, tramadol and their combination by youths who believe these drugs could positively impact their sexual life. Sildenafil citrate and tramadol are metabolized in the liver, and their by-products excreted through the kidneys, making these organs possible targets for toxicity. Aim: This study evaluates the effects of combination of tramadol and sildenafil citrate on hepatic and renal function parameters in male albino rats. Methodology: A total of forty-nine (49) male albino rats weighing between 150 to 180g were used for the study. Sildenafil citrate and tramadol were administered to the rats by means of oral gavage for 28 days. The liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined using the Reitman-Frankel method. Alkaline phosphatase (ALP) was determined using the Colorimetric endpoint method. Total protein (TP) was determined using the biuret method. Albumin (ALB) was determined using the bromocresol green method. Sodium (Na+), potassium (K+) and chloride (CL-) were determined using ion selective electrode (ISE) method. Bicarbonate (HCO3-) was determined using titrimetric method. Urea was determined using Urease bertholet method. Creatinine was determined using Jaffe-Slot method. Results: There were no significant differences (P>.05) in the liver enzymes ALT, AST and ALP in all the treatment groups compared to the negative control. Total protein (TP) and albumin (ALB) also showed no significant differences (P>.05) in the groups, compared to the negative control. there were no significant differences (P>.05) in the electrolyte levels in the treatment groups, compared to the negative control. Urea and creatinine levels were also not significantly different (P>.05) in the treatment groups, compared to the negative control. Conclusion: Administration of sildenafil citrate singularly and in combination with tramadol, at recommended and double doses for 28 days, did not impact the liver and was also non-toxic to the kidneys.

Electropolymerization of poly(phenol red) on laser-induced graphene electrode enhanced adsorption of zinc for electrochemical detection

We present a highly sensitive and selective electrode of laser-induced graphene modified with poly(phenol red) (P(PhR)@LIG) for measuring zinc nutrition in rice grains using square wave anodic stripping voltammetry (SWASV). The physicochemical properties of P(PhR)@LIG were investigated with scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier infrared spectroscopy (FT-IR) and Raman spectroscopy. The modified electrode demonstrated an amplified anodic stripping response of Zn2+ due to the electropolymerization of P(PhR), which enhanced analyte adsorption during the accumulation step of SWASV. Under optimized parameters, the developed sensor provided a linear range from 30 to 3000 μg L−1 with a detection limit of 14.5 μg L−1. The proposed electrode demonstrated good reproducibility and good anti-interference properties. The sensor detected zinc nutrition in rice grain samples with good accuracy and the results were consistent with the standard ICP-OES method.

Effects of Administration of Bouillon Cubes on Insulin Resistance, Lipid Profile and Renal Function Parameters in Female Albino Rats

Aim: To evaluate the effects of administration of bouillon cubes on insulin resistance, lipid profile and renal function parameters in female albino rats. Methodology: A total of thirty-five (35) female albino rats, weighing between 120 and 150 grams, were used for the study. The bouillon cubes, Star Maggi and Knorr were administered daily to the rats, using an oral gavage tube for 90days. Fasting plasma glucose (FPG) was determined using the Glucose oxidase method. Fasting plasma insulin (FPI) and Cystatin C levels were quantitatively determined by a rat-specific sandwich-enzyme linked immunosorbent assay (ELISA) method. Insulin resistance was determined using the homeostatic model assessment for insulin resistance (HOMA-IR) method. The electrolytes, sodium (Na+) and potassium (K+) and were determined using ion selective electrode method. Urea was determined using Urease-bertholet method. Creatinine was determined using the Jaffe-Slot method. Total Cholesterol (TC), Triglyceride (TG) and High-Density Lipoprotein Cholesterol (HDL-C) were determined by enzymatic methods. Low Density Lipoprotein Cholesterol (LDL-C) was calculated from the Friedewald’s equation. Kidney sections were stained using haematoxylin and eosin (H&E) staining technique. Quantitative analysis of monosodium glutamate (MSG) content of the bouillon cubes was analyzed using ultraviolet (UV) spectroscopy while the sodium content was analyzed using atomic absorption spectrophotometry according to the method of the American Public Health Association. Results: There were no significant differences (P>.05) in FPG, FPI and HOMA-IR in all the treatment groups. The mean cystatin C value in group E (High Dose Knorr) was significantly higher (P <.05) than the negative control and all other treatment groups. The results also show the mean sodium values in groups D (High Dose Maggi) and E (High Dose Knorr) were significantly lower (P <.05) when compared to the negative control. There were no significant differences (P >.05) in TC and HDL-C levels in the negative control, compared to the treatment groups. There were no significant differences (P >.05) in TG levels, except for group B (Low Dose Maggi) which significantly lower (P <.05) than the negative control. Also, there were no significant differences (P >.05) in LDL-C levels, except for group B (Low Dose Maggi) which significantly higher (P <.05) than the negative control. Histologic analysis of the kidneys of the treated groups showed histological changes in the architecture of the tissues indicating tissue distortion, acute tissue damage, glomerular nephritis and distorted capillaries and degeneration compared to the negative control group which showed no tissue distortion. Conclusion: Chronic exposure to bouillon cubes did not impact fasting plasma glucose, insulin and insulin resistance in the treated rats. Chronic administration of Knorr cubes impacted the integrity of the kidney as levels of cystatin C and sodium were altered in the albino rats. Histoarchitecture of the kidneys of the treated rats showed histological changes indicating tissue distortion, acute tissue damage, glomerular nephritis and distorted capillaries. Lipid profile/metabolism was relatively not affected by the administration of bouillon cubes.

Estimation of trace element of strontium ion using ion selective electrode based on a ceramic cordierite nanoparticle in some vegetarian foods

The development of an ion-selective electrode for the potentiometric measurement of strontium ions using ceramic nanoparticles (cordierite) as an ionophore was a concern in this study. The nano cordierite (Mg2Al4Si5O18) was synthesized by sol–gel method and subsequently characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, transmission electron microscope (TEM), scanning electron microscope (SEM) with EDAX unit and contact angle. The XRD results confirm the purity and crystalline structure of nanoparticles. The average crystallite size and particle size were studied by Debye-Scherrer equation, TEM, and SEM and it is found to be 16.9 and 29.29 nm which is a mesoporous structure. Cordierite nanoparticles were used to accelerate the electron transfer which refers to the extensive surface area, electrical characteristics, porous design, and nanoscale dimension. The carbon paste electrode optimization was done to study the potentiometric performance of Sr(II) ion detection. The electrode composition was 5.0 % synthetic ionophere, 28.9 % tricresylphosphate (TCP), and 65.8 % graphite powder (w/w). Stable potentiometric behavior was shown in the concentration range 1.0 × 10−6 −1.0 × 10−2 mol/L (R2 = 0.998). The electrode detection limit and response time were 5.0 × 10−7 mol/L and 6 s, respectively. As well as the electrode showed selectivity towards the Sr(II) ion in the vicinity of certain cation species. Also, it was performed without any variations in response within the pH range of 3–8. Additionally, Sr(II) ion determination was detected in some real samples (plant origin) such as legumes (kidney bean), cereals (wheat), leafy vegetables (cabbage), stems (onion), roots (carrot), fruits (tomatoes) and nuts (almond) with high recoveries and reproducibility through around 72 days. Subsequently, the outcome was assessed against the ICP technique's superior performance.

New Screen-Printed Solid Contact Ion Selective Electrode for Potentiometric Analysis of Tolterodine: Application of Analytical Eco-Scale and GAPI Metrics for Green Assessment

This research work focuses on the development and validation of a screen-printed solid contact ion-selective electrode (SP-SCE) for the potentiometric analysis of tolterodine (TOLT), a potent antimuscarinic drug. The sensor fabrication involved preparing a carbon paste electrode (CPE) modified with titanium dioxide (TiO2) nanoparticles, followed by depositing a membrane containing tolterodine phosphotungstate (TOLT-PTA) onto the electrode’s surface, then air-drying at room temperature for one day. The use of TOLT-PTA provides high selectivity for tolterodine and maintains a stable potential with a Nernstian slope. The incorporation of TiO2 nanoparticles enhances the electrode’s performance due to their high electrical conductivity and larger surface area, improving reaction rates, sensitivity, and response time. The validity of the proposed method was assessed according to ICH guidelines and IUPAC recommendations. A linear relationship was established between cell potentials and the logarithm of TOLT concentrations within (3.16 × 10−6) M to (1.00 × 10−2) M in pure form, with a Nernstian slope of 58.608 mV decade−1, a coefficient of determination (R2) of 0.9994. and an LOD of (1.58 × 10−6) M. Statistical comparisons with a previously reported method demonstrated no significant differences, indicating the accuracy of the developed method. It was used for determining TOLT in tablets successfully.

Demonstrating the Analytical Potential of a Wearable Microneedle-Based Device for Intradermal CO2 Detection.

Monitoring of carbon dioxide (CO2) body levels is crucial under several clinical conditions (e.g., human intensive care and acid-base disorders). To date, painful and risky arterial blood punctures have been performed to obtain discrete CO2 measurements needed in clinical setups. Although noninvasive alternatives have been proposed to assess CO2, these are currently limited to benchtop devices, requiring trained personnel, being tedious, and providing punctual information, among other disadvantages. To the best of our knowledge, the literature and market lack a wearable device for real-time, on-body monitoring of CO2. Accordingly, we have developed a microneedle (MN)-based sensor array, labeled as CO2-MN, comprising a combination of potentiometric pH- and carbonate (CO32-)-selective electrodes together with the reference electrode. The CO2-MN is built on an epidermal patch that allows it to reach the stratum corneum of the skin, measuring pH and CO32- concentrations directly into the interstitial fluid (ISF). The levels for the pH-CO32- tandem are then used to estimate the PCO2 in the ISF. Assessing the response of each individual MN, we found adequate response time (t95 < 5s), sensitivity (50.4 and -24.6 mV dec-1 for pH and CO32-, respectively), and stability (1.6 mV h-1 for pH and 2.1 mV h-1 for CO32-). We validated the intradermal measurements of CO2 at the ex vivo level, using pieces of rat skin, and then, with in vivo assays in anesthetized rats, showing the suitability of the CO2-MN wearable device for on-body measurements. A good correlation between ISF and blood CO2 concentrations was observed, demonstrating the high potential of the developed MN sensing technology as an alternative to blood-based analysis in the near future. Moreover, these results open new horizons in the noninvasive, real-time monitoring of CO2 as well as other clinically relevant gases.

Direct potentiometric bicarbonate/carbon dioxide sensing based on polymeric membranes doped with selective meso-bisubstituted calix[4]pyrrole ionophores.

We evaluated in this work the properties of a promising class of HCO3- ionophores, which have not been recognized previously. Three types of neutral or charged calix[4]pyrroles with meso-bisubstituted groups were evaluated as ionophores for polymeric membrane HCO3- selective electrodes. Optimizing membrane components, such as ionophores, lipophilic additives and plasticizers, yielded ISEs exhibiting Nernstian response to HCO3- with improved linear range and detection limits, while the selectivity sequence differs significantly from the Hofmeister series. Interference from important biological and environmental species was reduced significantly, especially that from SCN-, NO3-, Br- and Cl-, which are always at high concentrations in related samples. In order to provide more insights into the properties of the ionophores and performance of the proposed ISEs, the stability constants of anion-ionophore complexes in the membrane phase were determined. Studies on the influence of the sample solution pH demonstrated that the proposed ISEs can be employed in a wide pH range of 3.0-9.0 with fast response (<30 s), good reversibility and long shelf life. Moreover, the proposed ISEs were used to quantify the concentration of HCO3- and dissolved CO2 in mineral and beverage samples with good recoveries.

Water monitoring with an automated smart sensor supported with solar power for real-time and long range detection of ferrous iron.

Low-power and smart sensing systems for iron detection are necessary for in situ monitoring of water quality. Here, a potentiometric Fe2+-selective electrode (ISE) was fabricated based on cyanomethyl N-methyl-N-phenyl dithiocarbamate for the first time as an ionophore. Under optimal conditions, the ISE showed a Nernstian slope of 29.76 ± 0.6 mV per decade for Fe2+ ions over a wide concentration range from 1.0 × 10-1 to 1.0 × 10-5 M with a lower detection limit (LOD) of 1.0 × 10-6 M. The ISE interference of various cations on the potentiometric response was also investigated. The ISE had a response time less than 3 s and the lifetime was two months. Also, an automated, long-range (LoRa), wireless enabled sampling microfluidic device powered with a solar panel as an autonomous power source was developed for a continuous sampling and sensing process. The sensing platform was employed in the determination of Fe2+ in acid mine drainage and spiked water samples with an average recovery of 100.7%. This simple, inexpensive (below $350), portable sensing platform will allow for rapid real-time monitoring of ground-, drinking-, and industrial waters contaminated with iron.

Comparison of selectivity and sensitivity of various ferric selective electrodes prepared using N-((bis(dimethyl amino)methylene)carbamothioyl)benzamide.

N-((Bis(dimethyl amino)methylene)carbamothioyl)benzamide (NBMCB) was synthesized, characterized, and used as an ionophore for producing three novel ion-selective potentiometric sensors for Fe(III) determination. Firstly, using the molecular mechanic-based MMFF94 method, the most stable NBMCB's conformer and its isosteric complexes with various cations were determined. According to the Gibbs free energy results of the reaction, the thermodynamic complexation reactivity of Fe(III) and the ligand was acceptable. These results were obtained using the B3LYP approach and the 6-31G(d,p) basis set that was substituted for heavy metals by the LanL2DZ basis set. We used UV-visible spectrophotometry to confirm the tendency of NBMCB to react with Fe(III). Generally, three diverse liquid membrane ferric selective electrodes were obtained by the use of the specified ligand: classic with a liquid internal electrolyte-ferric selective electrode (LIE-FSE), solid state-FSE (SS-FSE), and coated wire-FSE (CW-FSE). The reactions exhibited Nernstian behavior across all electrodes. The limit of detection was enhanced for the SS-FSE (3 × 10-9 M) and the CW-FSE (3 × 10-7 M) in comparison with that of the LIE-FSE (7 × 10-7 M). The lifetime of the LIE-FSE was 8 weeks, while it was 10 weeks for the SS-FSE and the CW-FSE. Elimination of the internal solution reduced the limit of detection and prolonged the lifespan of the sensors. Also, the three electrodes all had a short response time of around 5-7 s. The sensors were utilized as indicator electrodes during the potentiometric titration of Fe(III) using ethylenediaminetetraacetic acid.

Selective Impedimetric Interdigitated Electrode for Sensing Gaseous, Biological, and Inorganic Targets: A State-of-the-Art Review

Selective Impedimetric Interdigitated Electrode for Sensing Gaseous, Biological, and Inorganic Targets: A State-of-the-Art Review

Stability-indicating determination of ciprofloxacin in the presence of its main photo-degradation product using solid-contact electrodes in river water

The application of membrane sensors for monitoring and evaluation of pharmaceutical environmental contaminants has become a significant aim in the past few years. Due to the wide applicability of ciprofloxacin hydrochloride (CPF) in medicine, there is a high probability of its presence in the environment, especially in surface water like river water. The long-term exposure of the river water to sunlight and the photoliability of CPF may increase its photo-degradation. Two selective and sensitive membrane electrodes were created to measure CPF when it is present with its main photo-degradant product. These were made using two ion pairing agents, which are sodium tetraphenylborate (TPB) and phosphotungstic acid (PTA). The linearity range of the manufactured electrodes was 1 × 10-6–1 × 10-2 M. The slopes of the CPF-TPB and CPF-PTA membrane electrodes are 60.1 ± 0.70 and 57.9 ± 0.90 mV/decade, respectively. The cited sensors showed adequate performance in a pH range from 2.0 to 5.0. All test parameters were fine-tuned to provide the best electrochemical performance. The manufactured membranes were successfully used to determine CPF in a sensitive way in the presence of its primary photodegradant. The cited sensors were effectively used to quantify CPF in river water samples, with no pre-treatment operations required.

Highly selective Ag foam gas diffusion electrodes for CO2 electroreduction by pulsed hydrogen bubble templation

The manuscript presents a novel approach for polymer-based Ag-DHBT-GDE fabrication, enabling highly efficient CO2 electrolysis to CO with remarkable performance and selectivity.

Removal of Fluoride from contaminated drinking water using Prosopis juliflora (Sw.) DC. Plant bark as an adsorbent

In India endemic fluorosis is considered as a major public health problem. The fluoride contamination and its removal approach attract a lot of concern from the scientific community at the global scale due to finite potable groundwater resource. In the present study, Guntral village from the Raichur district, Karnataka has been selected to know the fluoride concentration in ground water. The Groundwater samples were collected from bore wells and analyzed in the laboratory by using Ion Selective Electrode method and it was found that fluoride level from the range of 6.4-9.3 ppm from the different sampling sites. Further in order to remove fluoride, the adsorption method was followed by using Prosopis juliflora (Sw.) DC.Bark. The column method followed for removal of fluoride from the groundwater proved that 91.7 % after the treatment. Adsorption isotherm and kinetic models were well fitted to adsorption methods. It is clearly evidenced that bark of Prosopis juliflora (Sw.) DC adsorbent acts as one of the most significant and promising adsorbent for the removal of fluoride from the groundwater resources.

Chemical kinetics of silver diammine fluoride in demineralization and remineralization solutions-an in vitro study.

Silver Diammine Fluoride (SDF) is a clinical minimal intervention to manage dentin caries. Its chemistry in demineralization conditions has been investigated widely, but far less in remineralization conditions. The aim was to investigate and compare the chemical reactions when SDF is added to remineralization and demineralization solutions. 0.01 ml SDF (Riva Star) was added to deionized water (DW); demineralization (DS = pH4) and remineralization (RS = pH7.0) solutions. The time sequence of concentrations of NH4+, F-, and Ag+ were measured using ion selective electrodes (ISEs) every 2 min. The pH was also measured. Precipitates were characterized using x-ray Diffraction (XRD) and, 31P and 19F nuclear magnetic resonance spectroscopy (NMR). The concentrations of NH4+ and Ag+ showed decreasing trends in DW (-0.12 and -0.08 mM/h respectively), and in DS (-1.06 and -0.5 mM/h respectively); with corresponding increase in F- concentration (0.04 and 0.7 mM/h respectively). However, in RS, NH4+ concentration showed little change (0.001 mM/h), and Ag+ and F- concentrations were negligible. XRD results showed that precipitates (in RS only) contained AgCl, and metallic Ag. NMR showed that fluorapatite/carbonated fluorapatite (FAP/CFAP) were formed. The pH increased after SDF addition in all three solutions. SDF dissolved to release NH4+, F- and Ag + . In DW and DS, NH4+ combined with Ag+ to form diamminesilver, causing an increase of F- and pH. In RS, F- reacted with Ca2+ and (PO)43- to form FAP/CFAP, and Ag+ reacted with Cl- to form AgCl/Ag. These suggests why SDF is effective in managing dentin caries.

Classification techniques of ion selective electrode arrays in agriculture: a review.

Agriculture has a substantial demand for classification, and each agricultural product exhibits a unique ion signal. This paper summarizes the classification techniques of ion-selective electrode arrays in agriculture. Initially, data sample collection methods based on ion-selective electrode arrays are summarized. The paper then discusses the current state of classification algorithms from the perspectives of machine learning, artificial neural networks, extreme learning machines, and deep learning, along with their existing research in ion-selective electrodes and related fields. Then, the potential applications in crop and livestock growth status classification, soil classification, agricultural product quality classification, and agricultural product type classification are discussed. Ultimately, the future challenges of ion-selective electrode research are discussed from the perspectives of the sensor itself and algorithms combined with sensor arrays, which also positively impact the promotion of their application in agriculture. This work will advance the application of classification techniques combined with ion-selective electrode arrays in agriculture.

Study of Serum Magnesium, Potassium and Calcium in Acute Myocardial Infarction Patients

Introduction: A myocardial infarction happens when blood flow stops or decreases to the coronary arteries of the myocardial muscle, resulting in damage to the heart muscle. Magnesium is important electrolyte plays vital role in suppressing arrhythmias during myocardial ischemia and during reperfusion. Potassium is the most abundant cation of intracellular fluid. A significant correlation between hypokalemia and ventricular fibrillation is recorded. Calcium plays a vital role in myocardial muscle contraction. Aim: To study serum levels of magnesium, potassium and calcium in acute myocardial infarction patients. Material and methods: This was a prospective case control study conducted in Prathima Institute of medical sciences Nagunur, Karimnagar, Telangana state, India between January 2015 to December 2015. A total 50 acute myocardial infarction patients and 50 normal age and sex matched healthy controls selected for study. Serum magnesium estimated by colorimetric xylidyl blue complex method, serum potassium estimated by ion selective electrode method and serum calcium by OCPC method. Statistical analysis carried out using statistical software SPSS version 16 and p-value &lt; 0.05 considered statistically significant. Results: Serum levels of magnesium, potassium and calcium were significantly decreased in acute myocardial infarction patients when compared healthy controls and is statistically significant (&lt;0.05) Conclusion: The above study suggested decreased serum level of key elements such as magnesium, potassium and calcium in acute myocardial infarction patients when compared to healthy controls. Estimation and correction of these elements may play a pivotal role in management of patients with acute myocardial infarction