Development of a molecularly imprinted polymer-based electrochemical sensor for the selective detection of nerve agent VX metabolite ethyl methylphosphonic acid in human plasma and urine samples.

This study focuses on the detection of ethyl methyl phosphonic acid (EMPA), a metabolite of the banned organophosphorus nerve agent VX. We developed an electrochemical sensor utilizing the molecularly imprinted polymer (MIP) based on 4-aminobenzoic acid (4-ABA) and tetraethyl orthosilicate for the selective detection of EMPA in human plasma and urine samples. The 4-ABA@EMPA/MIP/GCE sensor was constructed by a thermal polymerization process on a glassy carbon electrode and sensor characterization was performed by cyclic voltammetry and electrochemical impedance spectroscopy. The 4-ABA@EMPA/MIP/GCE sensor demonstrated impressive linear ranges 1.0 × 10-10 M-2.5 × 10-9 M for the standard solution, 1.0 × 10-10 M-2.5 × 10-9 M for the urine sample, and 1.0 × 10-10 M-1 × 10-9 M of EMPA for the plasma sample with outstanding detection limits of 2.75 × 10-11 M (standard solution), 2.11 × 10-11 M (urine), and 2.36 × 10-11 M (plasma). The sensor exhibited excellent recovery percentages ranging from 99.86 to 101.30% in urine samples and 100.62 to 101.08% in plasma samples. These findings underscore the effectiveness of the 4-ABA@EMPA/MIP/GCE as a straightforward, highly sensitive, and selective interface capable of detecting the target analyte EMPA in human plasma and urine samples.

Comparative MIP sensor technique: photopolymerization or thermal polymerization for the sensitive determination of anticancer drug Regorafenib in different matrixes.

Regorafenib (REG) is a diphenylurea derivative oral multikinase inhibitor. It plays an important role in the treatment of colorectal cancer, metastatic gastrointestinal stromal tumors, and hepatocellular carcinoma. Molecularly imprinted polymer (MIP) based glassy carbon electrodes (GCE) were fabricated using photopolymerization (PP) and thermal polymerization (TP) methods. The characterizations of the proposed sensors were investigated by electrochemical techniques, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Several parameters were studied in detail for the optimum conditions of MIP-based sensors, such as dropping volume, photopolymerization and thermal polymerization durations, removal medium and time, and rebinding time. Both sensors' analytical validation and electroanalytical performance comparison were made in different REG concentrations ranging between 0.1 nM and 2.5 nM in standard solution and commercial human serum samples. The limit of detection (LOD) of PP-REG@MIP/GCE and TP-REG@MIP/GCE were 9.13 × 10-12 M and 1.44 × 10-11 M in standard solutions and 2.04 × 10-11 M and 2.02 × 10-11 M in serum samples, respectively. The applicability of the proposed sensors was tested using commercial human serum samples and pharmaceutical form of REG with high recovery values (PP-REG@MIP/GCE and TP REG@MIP/GCE sensors, 99.56-101.59%, respectively). The selectivity of the sensor for REG was investigated in the presence of similar molecules: Sorafenib, Sunitinib, Nilotinib, and Imatinib. The developed techniques and sensors checked the possible biological compounds and ions' effects and storage stability.

Achievements of Graphene and Its Derivatives Materials on Electrochemical Drug Assays and Drug-DNA Interactions.

Graphene, emerging as a true two-dimensional (2D) material, has attracted increasing attention due to its unique physical and electrochemical properties such as high surface area, excellent conductivity, high mechanical strength, and ease of functionalization and mass production. The entire scientific community recognizes the significance and potential impact of graphene. Electrochemical detection strategies have advantages such as being simple, fast, and low-cost. The use of graphene as an excellent interface for electrode modification provides a promising way to construct more sensitive and stable electrochemical (bio)sensors. The review presents sensors based on graphene and its derivatives for electrochemical drug assays from pharmaceutical dosage forms and biological samples. Future perspectives in this rapidly developing field are also discussed. In addition, the interaction of several important anticancer drug molecules with deoxyribonucleic acid (DNA) that was immobilized onto graphene-modified electrodes has been detailed in terms of dosage regulation and utility purposes.

Chiral Sensing as a Future Challenge in Electroanalytical Chemistry: Cyclodextrin-Based Chiral Sensors.

Chirality is an academically exciting and interesting topic, as most active ingredients have chirality. Chiral enantiomers with the same molecular shape show different effects from each other in terms of pharmacological, pharmacokinetic, and toxicology. There are many examples of these differences that have caused dramatic, even fatal damage. For these reasons, it is of great importance to developing an effective method to achieve chiral identification and separation, and chiral separation methods are becoming increasingly important in both the pharmaceutical industry and clinical studies. Electrochemical techniques, which can provide many advantages over other classical methods, have attracted great interest in chiral recognition in recent years. In this review, extensive and critical research of the trends in chiral recognition in recent studies is explained. Especially the role of cyclodextrins derivatives in chiral analysis has been investigated and the studies related to this are explained and given in the tables. In addition, some remarks and future perspectives in the field of chiral recognition are also discussed in the concluding part.

The Power of Carbon Nanotubes on Sensitive Drug Determination Methods.

Nowadays, carbon nanotubes (CNTs) due to their inorganic conducting, semiconducting, and organic π-π stacking properties are becoming innovative materials. CNTs have an adjustable size, large surface area, and other significant chemical properties. Due to their excellent electrical, optical, and mechanical properties, CNTs play an important role in various application fields. In the past decade, many unique intrinsic physical and chemical properties have been intensively explored for pharmaceutical, biological, and biomedical applications. The functionalization of CNTs results in a remarkably reduced cytotoxicity and at the same time increased biocompatibility. The toxicity studies reveal that highly water-soluble and serum stable nanotubes are biocompatible, nontoxic, and potentially useful for biomedical applications. Ultrasensitive drug determination from its dosage form and/or biological samples with carbon nanotubes can be realized after surface modification. The main purpose of this review is to present recent achievements on CNTs which are investigated in electrochemical and chromatographically sensing technologies.

Current Advances in Electrochemical Biosensors and Nanobiosensors.

Electrochemical biosensors have wider interest in the last decades than other analytical techniques such as chromatography, spectrophotometry, fluorescence, migration techniques and flow systems. Since they provide practicality, sensitivity, and fast response, these systems can be integrated with labs-on-chips to obtain excellent point of care analytical platforms. They are excellent devices for wide range of analytes such as drugs, proteins, markers, bacteria, and viruses etc. due to their unique features. Electrochemical methods are also successful at molecular recognition, user friendliness, sensitive responses, requirement of small volume reactive of reagents, low cost, and applicability to point of care tests. DNA, enzyme and immunosensor based biosensors are widely used as well. According to recent studies of electrochemical biosensors, nanomaterials and polymers have been used to increase the performance of biosensors. In this review, the recent studies of electrochemical biosensors have been presented with their applications at various fields.

Application of Nanomaterials in Development of Electrochemical Sensors and Drug Delivery Systems for Anticancer Drugs and Cancer Biomarkers.

Worldwide occurrence of cancer has initiated a global effort for the development and production of various anticancer drugs. Unfortunately, high potential toxicity and mutagenic and carcinogenic side effects have been reported for most of the anticancer drugs, which cause many problems for the patient even at a slight dosage. Considering this, thanks to their outstanding features such as high sensitivity, selectivity, and cheapness, electrochemical methods have received much attention in the development of quick, precise, and reliable (bio) sensors for the monitoring of anticancer drugs and cancer biomarkers. Here, procedures and approaches presented for the development of modified electrodes based on nanomaterials employed for the anticancer drugs and cancer biomarkers sensing are reviewed. The analytical performance of the constructed electrodes including physical and electrochemical properties together with their figures of merits is highlighted. Nanomaterials offer excellent features for anticancer drugs. They improve multi-drug resistance, site-specificity and enhance efficient delivery. The premature degradation, preventing interaction with biological systems, absorption of the drugs into the selected tissues, controlling of the pharmacokinetic properties and skipping distribution profile can be performed with nanomaterials. In this review, detailed features of nanomaterials in anticancer drug delivery systems will be presented together with the application of nanomaterials in electrochemical sensors.

Current Status of Drug Delivery Approaches and Assay of Anti-Migraine Drugs.

Migraine is a chronic, painful, neurological disorder that affects approximately 15% of the population worldwide. It is a form of neurovascular headache: a disorder in which neural events result in the dilation of blood vessels that, in turn, results in pain and further nerve activation. The pathogenesis of migraine is not completely understood, but it is thought that both central and peripheral stimulations can play a role in migraine. Experimental pharmacological evidence suggests that some drugs can have actions in migraine treatment and oral drug delivery is the first choice for these drugs. However, the oral absorption of many drugs is delayed during migraine attacks. Therefore, there may be an advantage to other drug delivery routes, such as parenteral and intranasal. Moreover, nanoparticles can be used for improved drug delivery of anti-migraine agents as they can protect the encapsulated drug from biological and/or chemical degradation, and extracellular transport by P-gp efflux proteins. Various analytical studies have been performed to sensitive and selective assays of antimigraine drugs from commercial and real samples. Anti-migraines, either single or combined with other drugs, can be easily detected by several analytical methods, such as ultraviolet spectrometry, visible spectrometry, high-performance liquid chromatography, liquid chromatography-mass spectrometry, and high-performance thin layer chromatography. This review focuses on the status of antimigraine drug delivery technologies and possible routes for drug delivery. Moreover, it will present their analytical assays with different methods.

Development, optimization and in vitro evaluation of oxaliplatin loaded nanoparticles in non-small cell lung cancer.

BACKGROUND: Platinum-based chemotherapy in non-small cell lung cancer (NSCLC) has been demonstrated as a promising approach by many researchers. However, due to low bioavailability and several side effects, drug targeting to lungs by intravenous administration is not a common route of administration. OBJECTIVE: In this study, oxaliplatin loaded polycaprolactone (PCL) nanoparticles were prepared to overcome the limitations of the drug. 33 factorial design was used to evaluate the combined effect of the selected variables on the nanoparticle characteristics and to optimize oxaliplatin loaded PCL nanoparticles. METHODS: The factorial design was used to study the influence of three different independent variables on the response of nanoparticle particle size, polydispersity index (PDI), zeta potential, and encapsulation efficiency. The cellular uptakes of oxaliplatin loaded nanoparticles with different molecular weights of PCL were evaluated. Moreover, optimized nanoparticles were evaluated for their efficacy in non-small lung cancer using the SK-MES-1 cell line. RESULTS: In factorial design, it is found that the homogenization speed and surfactant ratio represented the main factors influencing particle size and PDI and did not seem to depend on the PCL ratio. While the cytotoxicity of free oxaliplatin and oxaliplatin loaded nanoparticles were similar in low drug doses (2.5 and 25 µg/mL), the cytotoxicity of oxaliplatin loaded nanoparticles on SK-MES-1 cell was found higher in higher doses (p < 0.05). Moreover, oxaliplatin nanoparticles formulated with different molecular weights of PCL did not show significant differences in cellular uptake in 1 h and 2 h. However, the uptake of PCL80000 NPs was found significantly greater than free oxaliplatin at 4 h (p < 0.05). CONCLUSION: Hence, the development of oxaliplatin loaded PCL nanoparticles can be a useful approach for effective NSCLC therapy. Development, optimization and in vitro evaluation of oxaliplatin loaded nanoparticles in non-small cell lung cancer.

Withdrawal Notice: Application of Nanomaterials in Development of Electrochemical Sensors and Drug Delivery Systems for Anticancer Drugs

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A sensitive nanocomposite design via carbon nanotube and silver nanoparticles: Selective probing of Emedastine Difumarate.

In this study, a novel and sensitive nanocomposite of carboxylate-functionalized multiwalled carbon nanotube (COOH-fMWCNT) and silver nanoparticles (AgNPs) was fabricated and used to modify a glassy carbon electrode (GCE) by a simple drop casting method. Modified electrode was then applied for selective determination of emedastine difumarate (EDD). The COOH-fMWCNT/AgNPs nanocomposite was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and cyclic voltammetry (CV). EDD showed two oxidation peaks at 0.634 and 1.2 V on the GCE surface. CV results of COOH-fMWCNT/AgNPs/GCE displayed superior electrocatalytic performance in terms of anodic peak current of EDD when compared to AgNPs/GCE, MWCNT/GCE, and COOH-fMWCNT/GCE. The experimental conditions such as effect of pH, supporting electrolyte, effect of accumulation time and potential, scan rate were optimized for getting intense current signals of the target analyte. Under optimized conditions, COOH-fMWCNT/AgNPs/GCE showed a linear current response for oxidation of EDD in the range of 1.0 × 10-7-1.0 × 10-4 M, with a limit of detection (LOD) and quantification (LOQ) of 5.25 nM, 15.9 nM, respectively, in 0.1 M phosphate buffer solution at pH 2.0 using differential pulse adsorptive stripping voltammetry technique. The proposed method was successfully applied for determination of EDD in pharmaceutical dosage form. Satisfactory recovery percentages were achieved from eye drop sample with acceptable RSD values (less than 2 %). Furthermore, the reproducibility, stability and repeatability of the modified electrode were studied.

A Review: New Trends in Electrode Systems for Sensitive Drug and Biomolecule Analysis.

Drug and biomolecule analysis with high precision, fast response, not expensive, and user-friendly methods have been very important for developing technology and clinical applications. Electrochemical methods are highly capable for assaying the concentration of electroactive drug or biomolecule and supply excellent knowledge concerning its physical and chemical properties such as electron transfer rates, diffusion coefficients, electron transfer number, and oxidation potential. Electrochemical methods have been widely applied because of their accuracy, sensitivity, cheapness, and can applied on-site determinations of various substances. The progress on electronics has allowed developing reliable, more sensitive and less expensive instrumentations, which have significant contribution in the area of drug development, drug and biomolecule analysis. The developing new sensors for electrochemical analysis of these compounds have growing interest in recent years. Screen-printed based electrodes have a great interest in electrochemical analysis of various drugs and biomolecules due to their easy manufacturing procedure of the electrode allow the transfer of electrochemical laboratory experiments for disposable on-site analysis of some compounds. Paper based electrodes are also fabricated by new technology. They can be preferred due to their easy, cheap, portable, disposable, and offering high sensitivity properties for many application field such as environmental monitoring, food quality control, clinical diagnosis, drug, and biomolecules analysis. In this review, the recent electrochemical drug and biomolecule (DNA, RNA, µRNA, Biomarkers, etc.) studies will be presented that involve new trend disposable electrodes.

Combination of Efficiency with Easiness, Speed, and Cheapness in Development of Sensitive Electrochemical Sensors.

Nowadays, electrochemical techniques can be considered as a suitable alternative technique besides UV/Vis spectroscopy, liquid chromatography, capillary electrophoresis, mass spectroscopy, NMR for evaluation and determination of different electroactive compounds. Solid electrodes such as carbon and metal-based substrates are common for electrochemical applications. Especially, during two past decades, different types of modified electrodes with these solid electrodes have been developed for fast, sensitive, and selective analysis of various important analyses (biomolecules, enzymes, and drugs) in a wide range of real samples. These applications are highly efficient, cost effective and facile fabrication procedures of the electrode modification can be employed. In the present review, at first, some recently developed high performance bare and modified electrodes are evaluated based on their outstanding properties. In the next step, developed new procedures or fabricated modified electrodes with good sensitivity based on simple and cheap protocols are introduced and discussed.

A new sensing platform based on NH2fMWCNTs for the determination of antiarrhythmic drug Propafenone in pharmaceutical dosage forms.

A novel sensor based on a modification of glassy carbon electrode (GCE) with NH2-functionalized multi-walled carbon nano-tubes (NH2fMWCNTs) is reported and its applicability to the electrochemical sensing of Propafenone (PPF) demonstrated. The electrochemical catalytic activity was also utilized as a sensitive detection method for the investigation of the detailed redox mechanism of PFF using cyclic and and differential pulse voltammetry. The surface morphology of the sensor was investigated by SEM armed with EDX probe. Electrochemical impedance spectroscopy was employed as well to define the electron transfer capability of modified and bare electrodes. Key experimental and instrumental conditions related to electrochemical determination by cyclic, differential pulse, and square wave voltammetry, such as amount of modifier, pH, scan rate, accumulation time and potential were studied and optimized. The results have shown a significant enhancement of the peak current after modifying the electrode; the calibration curves of PPF offering good linearity from 0.1 to 10 µM, limit of quantification (LOQ) being 0.03 µM and limit of detection (LOD) 0.01 µM, both when using DPV technique. The proposed sensor was successfully applied to the determination of PFF in dosage form without any special purification, separation or pre-treatment steps. The results of analyses obtained with the proposed sensor were satisfactory and fully statistically relevant.

Modern Assay Techniques for Cancer Drugs: Electroanalytical and Liquid Chromatography Methods.

In the past decades, patients who have chemotherapy treatment have considerably increased number. At this point, the development of rapid precise, and reliable methods are very important to analyze cancer drugs from their dosage forms, animals or human biological samples. Among all the analytical methods, electrochemical methods hold an important position with their unique properties such as specificity in the biological recognition process, fast response, and their reliability and do not need a pretreatment process. Chromatographic methods are also used in a wide range of analytical applications for the analyses of anticancer drugs. The power of chromatography comes from its ability to separate a mixture of analytes and determination of their concentrations. Chromatographic techniques can mainly be divided into gas, liquid, and supercritical fluid chromatography. In the frame of this information, this review is aimed to provide basic principles of electroanalytical and high-performance liquid chromatography methods for the analysis of cancer drugs. In addition, some selected applications for electrochemistry-related techniques and high-performance liquid chromatography, for the determination of anti-cancer pharmaceuticals published in the last five years are also discussed.

Recent progress on the sensitive detection of cardiovascular disease markers by electrochemical-based biosensors.

Cardiovascular disease is the most reason for deaths in all over the world. Hence, biomarkers of cardiovascular diseases are very crucial for diagnosis and management process. Biomarker detection demand is opened the important way in biosensor development field. Rapid, cheap, portable, precise, selective and sensitive biomarker sensing devices are needed at this point to detect and predict disease. A cardiac biomarker can be orderable as C-reactive protein, troponin I or T, myoglobin, tumor necrosis factor alpha, interleukin-6, interleukin-1, lipoprotein-associated phospholipase, low-density lipoprotein and myeloperoxidase. They are used for prediction of cardiovascular diseases. There are many methods for early diagnosis of cardiovascular diseases, but these have long time process and expensive devices. In recent studies, different biosensors have been developed to remove the problems in this field. Electrochemical devices and developed biosensors have many superiorities than others such as low cost, mobile, reliable, repeatable, need a little amount of solution. In this review, recent studies were presented as details for cardiovascular disease biomarkers detection using electrochemical methods.

Electrochemical Detectors in Liquid Chromatography: Recent Trends in Pharmaceutical and Biomedical Analysis.

Liquid chromatography (LC) coupled to an electrochemical (EC) detector is a complementary analytical tool compared to LC coupled with optical or mass spectrometry detectors (LC-MS). LC-EC can be applied to the determination of molecules difficult to be analyzed by other commercially available detectors. New EC detector design and new working electrode material have extended the scope of application in the field of pharmaceutical compounds analysis. Combining EC with LC-MS offers additional advantages compared to optical detectors in terms of drug stability and drug metabolism mimicry studies. Selected literature devoted to pharmacologically active compounds in their dosage forms, herbal drugs in natural products, drug residues in feed and/or in biological samples are reported in this review.