Simultaneous electrochemical determination of epinephrine and uric acid at 1-butyl-4-methyl-pyridinium tetrafluroborate ionic liquid modified carbon paste electrode: A voltammetric study

Determination of Salicylic Acid Using a Highly Sensitive and New Electroanalytical Sensor

Background:

A drug sensor (salicylic acid, in this case) was designed and made up of this research. The senor was made by modification of paste electrode (MPE) with CuO-SWCNTs and 1-hexyl-3-methylimidazolium chloride (HMICl). The MPE/CuO-SWCNTs/HMICl showed catalytic activity for the oxidation signal of salicylic acid in phosphate buffer solution.

Methods:

Electrochemical methods were used as a powerful strategy for the determination of salicylic acid in pharmaceutical samples. Aiming at this goal, carbon paste electrode was amplified with conductive materials and used as a working electrode.

Results:

The MPE/CuO-SWCNTs/HMICl was used for the determination of salicylic acid in the concentration range of 1.0 nM – 230 µM using differential pulse voltammetric (DPV) method. At pH=7.0, as optimum condition, the MPE/CuOSWCNTs/HMICl displayed a high-quality ability for the determination of salicylic acid in urine, pharmaceutical serum, and water samples.

Conclusion:

The MPE/CuO-SWCNTs/HMICl was successfully used as a new and high performance working electrode for the determination of salicylic acid at a nanomolar level and in real samples.

Recent Advantages of Mediator Based Chemically Modified Electrodes; Powerful Approach in Electroanalytical Chemistry

Background:

Modified electrodes have advanced from the initial studies aimed at understanding electron transfer in films to applications in areas such as energy production and analytical chemistry. This review emphasizes the major classes of modified electrodes with mediators that are being explored for improving analytical methodology. Chemically modified electrodes (CMEs) have been widely used to counter the problems of poor sensitivity and selectivity faced in bare electrodes. We have briefly reviewed the organometallic and organic mediators that have been extensively employed to engineer adapted electrode surfaces for the detection of different compounds. Also, the characteristics of the materials that improve the electrocatalytic activity of the modified surfaces are discussed.

Objective:

Improvement and promotion of pragmatic CMEs have generated a diversity of novel and probable strong detection prospects for electroanalysis. While the capability of handling the chemical nature of the electrode/solution interface accurately and creatively increases , it is predictable that different mediators-based CMEs could be developed with electrocatalytic activity and completely new applications be advanced.

Properties and Recent Advantages of N,N’-dialkylimidazolium-ion Liquids Application in Electrochemistry

:

N,Nʹ-dialkylimidazolium-ion liquids is one of the important ionic liquids with a wide range of application as conductive electrolyte and in electrochemistry. The modified electrodes create a new view in fabrication of electroanalytical sensors. Many modifiers have beeen suggested for modification of electroanalytical sensor since many years ago. Over these years, ionic liquids and especially room temperature ionic liquids have attracted more attention due to their wide range of electrochemical windows and high electrical conductivity. N,Nʹ-dialkylimidazolium-ion liquids are one of the main important ionic liquids suggested for modification of bare electrodes and especially carbon paste electrodes. Although many review articles have reported onthe use of ionic liquids in electrochemical sensors, no review article has been specifically introduced so far on the review of the advantages of N,Nʹ-dialkylimidazolium ionic liquid. Therefore, in this review paper we focused on the introduction of recent advantages of N,Nʹ-dialkyl imidazolium ionic liquid in electrochemistry.

Fabrication of Electrochemical Sensor for Epinine Determination Amplified with MgO/CNTs Nanocomposite and Ionic Liquid

Background:

Catecholamines are a large group of pharmacological and biological compounds that are widely used in biological systems. These compounds are prepared both naturally and synthetically with many key roles in the human body and its activities. Therefore, many researchers focused on the identification and determination of catecholamines in biological samples.

Methods:

MgO/SWCNTs were synthesized through the chemical precipitation method. In addition, cyclic voltammetry, differential pulse voltammetry, and chronoamperometric methods were used for the electro-oxidation reaction study of epinine at the surface of the modified electrode.

Results:

Carbon paste electrode (CPE) modified with MgO/SWCNTs nanocomposite and 1-butyl- 3-methylimidazolium methanesulfonate (BMMS) was used as an electrochemical sensor for the determination of epinine. The results showed a linear dynamic range of 5.0 nM-250 μM with a detection limit of 0.1 nM for epinine determination using MgO/SWCNTs/BMMS/CPE as a sensor.

Conclusion:

In the present study, a highly sensitive electrochemical sensor was designed and fabricated as an analytical tool for the determination of epinine. MgO/SWCNTs/BMMS/CPE was successfully used for the determination of epinine in water and dextrose saline with an acceptable recovery range of 98.7%-102.72%.

Sonochemical synthesis of bismuth(III) oxide decorated reduced graphene oxide nanocomposite for detection of hormone (epinephrine) in human and rat serum

Herein, we report an efficient electrochemical sensor strategy for determination of epinephrine based on Bi₂O₃ nanoparticle decorated reduced graphene oxide nanocomposite (Bi₂O₃@RGO). The Bi₂O₃@RGO was prepared by simple ultrasonic method and then it's morphological and crystal structure aspects were well characterized by physiological instruments. The electrode-electrolyte interfacial properties were examined to ensure the catalytic ability of composite sensing towards EP. The composite was deposited on the multi-conventional screen-printed electrode and was found to be desirable performance toward EP oxidation. The amperometric EP sensing exhibited good reproducible and sensitive which able to detect as low as concentration of 2.14 nM. Furthermore, good reproducibility, long-term stability and repeatability were obtained from the electrode in experiment. Moreover, the EP sensing method was successfully applied in human and rat blood serum, the recoveries were validated by HPLC method. It indicates the reliability of the method in practical analysis.

Nickel oxide nanoparticles/ionic liquid crystal modified carbon composite electrode for determination of neurotransmitters and paracetamol

Ionic liquid crystals mimic the natural bio-based ionic liquid crystals such as cell membrane structures in their interactions with drugs.

Determination of epinephrine in human serum using a Pt electrode modified by polyaniline–poly(3-methylthiophene)–poly(3,3′-diaminobenzidine)

A Pt electrode modified by polyaniline–poly(3-methylthiophene)–poly(3,3′-diaminobenzidine) was used for amperometric determination of epinephrine in a solution of NaHSO4/Na2SO4 (pH 2.0). For these studies, potentials between 0.40 and 0.50 V were applied, and the best response was obtained at 0.45 V. The limit of detection, limit of quantification, and the linear dynamic range were 1.23 × 10−4, 4.10 × 10−4, and 4.10 × 10−4 to 100.0 mmol L−1, respectively. These results were compared with determinations using Pt electrodes that were coated and uncoated with homopolymers. To check the accuracy of the developed method and the matrices interference, determination of epinephrine was performed in human serum samples using this modified electrode. The epinephrine concentrations were adjusted to 1.0 and 5.0 mmol L−1, and recovery values were calculated as 100.4% and 96.8%, respectively. It is significant that the determination of epinephrine was carried out at a lower potential (0.45 V) than the oxidation potential of epinephrine (0.65 V) without any matrix effect.

Ag ion irradiated based sensor for the electrochemical determination of epinephrine and 5-hydroxytryptamine in human biological fluids

A promising and highly sensitive voltammetric method has been developed for the first time for the determination of epinephrine (EP) and 5-hydroxytryptamine (5-HT) using 120 MeV Ag ion irradiated multi-walled carbon nano tube (MWCNT) based sensor. The MWCNT were irradiated at various fluences of 1e12, 3e12 and 1e13 ions cm(-2) using palletron accelerator. The simultaneous determination of EP and 5-HT has been carried out in phosphate buffer solution of pH 7.20 using square wave voltammetry and cyclic voltammetry. Experimental results suggested that irradiation of MWCNT by Ag ions enhanced the electrocatalytic activity due to increase in effective surface area and insertion of Ag ions, leading to a remarkable enhancement in peak currents and shift of peak potentials to less positive values as compared to the unirradiated MWCNT (pristine). The developed sensor exhibited a linear relationship between peak current and concentration of EP and 5-HT in the range 0.1-105 μM with detection limit (3σ/b) of 2 nM and 0.75 nM, respectively. The practical utility of irradiation based MWCNT sensor has been demonstrated for the determination of EP and 5-HT in human urine and blood samples.