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During the COVID-19 process, determination-based analytical chemistry studies have had a major place at every stage. Many analytical techniques have been used in both diagnostic studies and drug analysis. Among these, electrochemical sensors are frequently preferred due to their high sensitivity, selectivity, short analysis time, reliability, ease of sample preparation, and low use of organic solvents. For the determination of drugs used in the SARS-CoV-2, such as favipiravir, molnupiravir, ribavirin, etc., electrochemical (nano)sensors are widely used in both pharmaceutical and biological samples. Diagnosis is the most critical step in the management of the disease, and electrochemical sensor tools are widely preferred for this purpose. Diagnostic electrochemical sensor tools can be biosensor-, nano biosensor-, or MIP-based sensors and utilize a wide variety of analytes such as viral proteins, viral RNA, antibodies, etc. This review overviews the sensor applications in SARS-CoV-2 in terms of diagnosis and determination of drugs by evaluating the most recent studies in the literature. In this way, it is aimed to compile the developments so far by shedding light on the most recent studies and giving ideas to researchers for future studies. [ABSTRACT FROM AUTHOR]

Nowadays, the rapid improvements in the medical and pharmaceutical fields increase the diversity and use of drugs. However, problems such as the use of multiple or combined drugs in the treatment of diseases and insensible use of over-the-counter drugs have caused concerns about the side-effect profiles and therapeutic ranges of drugs and environmental contamination and pollution problems due to pharmaceuticals waste. Therefore, the analysis of drugs in various media such as biological, pharmaceutical, and environmental samples is an important topic of discussion. Electrochemical methods are advantageous for sensor applications due to their easy application, low cost, versatility, high sensitivity, and environmentally-friendliness. Carbon nanomaterials such as diamond-like carbon thin films, carbon nanotubes, carbon nanofibers, graphene oxide, and nanodiamonds are used to enhance the performance of the electrochemical sensors with catalytic effects. To further improve this effect, it is aimed to create hybrid platforms by using different carbon nanomaterials together or with materials such as conductive polymers and ionic liquids. In this review, the most used carbon nanoforms will be evaluated in terms of electrochemical characterizations and physicochemical properties. Furthermore, the effect of hybrid platforms developed in the most recent studies on electrochemical sensors will be examined and evaluated in terms of drug analysis studies in the last five years. [ABSTRACT FROM AUTHOR]

The first electrochemical sensor application in the literature is described for the sensitive and selective determination of the selective Janus kinase (JAK)-1 inhibitor abrocitinib (ABR). ABR is approved by the U.S. Food and Drug Administration (FDA) for the treatment of atopic dermatitis. The molecularly imprinted polymer (MIP)-based sensor was designed to incorporate zinc nanoflower (ZnNFs)-graphene oxide (GO) conjugate (ZnNFs@GO), synthesized from the root methanolic extract (RME) of the species Alkanna cappadocica Boiss. et Bal. to improve the porosity and effective surface area of the glassy carbon electrode (GCE). Furthermore, the MIP structure was prepared using ABR as a template molecule, 4-aminobenzoic acid (4-ABA) as a functional monomer, and other additional components. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the surface and structure of the synthesized nanomaterial and MIP-based surface. Among the electrochemical methods, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were preferred for detailed electrochemical characterization, and differential pulse voltammetry (DPV) was preferred for all other electrochemical measurements using 5.0 mM [Fe(CN)6]3–/4– solution as the redox probe. The MIP-based sensor, which was the result of a detailed optimization phase, gave a linear response in the 1.0 × 10–13 – 1.0 × 10–12 M range in standard solution and serum sample. The obtained limit of detection (LOD) and limit of quantification (LOQ) values and recovery studies demonstrated the sensitivity, accuracy, and applicability of the sensor. Selectivity, the most important feature of the MIP-based sensor, was verified by imprinting factor calculations using ibrutinib, ruxolitinib, tofacitinib, zonisamide, and acetazolamide. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Tofacitinib citrate (TOF) is a Janus kinase-3 inhibitor used for rheumatoid arthritis treatment. In this study, a molecularly imprinted polymer (MIP)–based sensor was produced using acrylamide as the functional monomer via photopolymerization technique for the electrochemical determination of TOF. This study is the first one to explain the electrochemical determination of TOF with a highly selective MIP-based sensor. The surface characterization of the MIP-based sensor was performed with scanning electron microscopy and energy-dispersive X-ray spectroscopy methods, and it was expanded with electrochemical characterization by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) methods. TOF determination was performed using differential pulse voltammetry (DPV) and EIS methods in standard solution and spiked serum sample in the linear range between 1×10−11 M and 1×10−10 M. Very low limit of detection and limit of quantification values were found, confirming the sensitivity of the sensor. Recovery analysis with spiked serum and tablet samples verified the sensor's accuracy and applicability using DPV and EIS methods. The selectivity of the sensor was confirmed with imprinting factor and interference studies, and the sensor performance was controlled using non-imprinted polymer for comparison at every step. [ABSTRACT FROM AUTHOR]

Tiotropium bromide (TIO) is a long-acting bronchodilator used in the treatment of chronic obstructive pulmonary disease (COPD) and asthma. Specifically, it is used to prevent patients from worsening breathing difficulties. In this study, a new TIO-imprinted electrochemical sensor was designed to detect TIO in serum and pharmaceutical samples. Methacryloyl-L-histidine-cobalt(II) [MAH-Co(II)] has been used as a metal-chelating monomer for synthesizing selective molecularly imprinted polymer (MIP). MIP film has been developed on glassy carbon electrodes using MAH-Co(II) as the functional monomer, 2-hydroxyethyl methacrylate (HEMA) as the basic monomer, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker in the photopolymerization method. The surface characterization of the developed MAH-Co(II)@MIP/GCE electrochemical sensor was done using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Also, the electrochemical behavior of the sensor was provided by differential pulse voltammetry (DPV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. Under optimized experimental conditions, the linearity range was in the range of 10–100 fM, and the limit of detection (LOD) and limit of quantitation (LOQ) values were calculated as 2.73 fM and 9.75 fM, respectively. The MAH-Co(II)@MIP/GCE sensor was used to precisely determine TIO in capsule and commercial serum samples. The results demonstrated that the MIP could specifically recognize TIO compared to structurally related drugs and could be reliably applied to the direct determination of drugs from real samples. [ABSTRACT FROM AUTHOR]

Contamination of environmental sources such as soils, sediments and rivers and human exposure caused by several endocrine disrupting compounds (EDCs) are considered as the most challenging issues of today's world. EDCs cover a wide variety of compounds ranging from phthalates to parabens and bisphenols (BPs) are the leading group among them. BPs are widely used during the production of different plastic materials such as food and beverage containers, toys, medical equipment and baby bottles that we use in every aspect of our lives. BPs may migrate from those products to different media under certain conditions and this situation causes chronic exposure for humans and other creatures in the environment. Especially bisphenol A (BPA) and its other analogues such as bisphenol F, bisphenol S and tetrabromobisphenol that have similar structures and are preferred as alternatives to BPA cause harmful adverse effects such as endocrine disruption, neurotoxicity, genotoxicity and cytotoxicity. There are legal restrictions and prohibitions by the European Union (EU) in order to prevent possible harmful effects. Therefore, it is important to develop highly sensitive, fast, easy to use and cheap sensors for the determination of BPs in biological, environmental and commercial samples. Electrochemical sensors, which are one of the most widely, used analytical techniques, provide these conditions. Additionally, it is possible to enhance the performance of electrochemical sensors with nanomaterials, molecularly imprinted polymers or aptamer based technologies. This review aims to give comprehensive information about BPs with summarizing most recent applications of electrochemical sensors for their determination in different samples. [ABSTRACT FROM AUTHOR]

A new electrochemical sensor based on molecularly imprinted tetraethyl orthosilicate (TEOS)-based porous interface was developed for selective recognition of bisphenol F (BPF) in this study. The sensor was prepared by depositing the solution containing TEOS and L-tryptophan (L-Trp) in the presence of cetyltrimethylammonium bromide (CTAB) as a pore-maker via hydrolysis/condensation reaction on the glassy carbon electrode (GCE). While the surface morphology and structure characterization were carried out using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), electrochemical characterization was performed through electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The resulted MIP(TEOS:L-Trp)@GCE achieved a wide linear range of 1 × 10−15–1 × 10−14 M for BPF detection with an excellent detection limit of 0.291 fM. Furthermore, the recovery of BPF from spiked bottled water and serum samples varied between 98.83 and 101.03%. These results demonstrate that MIP(TEOS:L-Trp)@GCE was found to be a simple, sensitive, and selective smart interface to detect trace pollution even from complicated samples. [ABSTRACT FROM AUTHOR]

Conductive boron-doped diamond (BDD), in addition to its superior material properties, offers many important advantages that make it an interesting material for electroanalytical studies. It has been considered as an excellent electrode material for electrooxidation of drug active compounds in their dosage forms or in biological materials due to its good physical and chemical properties. It contains not only the largest solvent working potential window compared to other electrode materials, but also it has low background and capacitive currents; lower problems with passivation and it has the ability to withstand extreme potentials, corrosive, and high temperature/pressure environments. The aim of this review is not only to provide a state-of-the-art of diamond electrochemistry but also to serve as a reference point for any researcher wishing to commence work with diamond electrodes and understand electrochemical data. Therefore, it is focused on the carbon-based materials, electrochemical properties of the BDD film electrode, its fundamental research, and its electrochemical pretreatment process are discussed in detail. In this case, there are important studies to show the effective BDD drug sensors for the detection and determination of drugs and the present review critically summarizes the available data in this field between 2015 and 2020. [ABSTRACT FROM AUTHOR]

Cancer is one of the leading causes of death worldwide. It is very important to regulate drug doses for cancer patients in the treatment of cancer with drugs. Determination of drugs used as anticancer at low concentrations and determination of them with high sensitivity is of great importance for the follow-up of these drugs. Electrochemical techniques offer a wide variety of detection techniques that provide user-friendly, low-cost, and real-time monitoring compared to other conventional methods and provide low sensitivity and detection limits. By modifying the electrode surfaces with various materials, their sensitivity and detection limits can be increased. This review focuses on new electrocatalytic approaches and current developments for the electrochemical determination of anticancer drugs. In addition, anticancer drugs are classified in detail. Electrochemical sensors used in studies in recent years and verification parameters such as detection limit, linear dynamic range, sensitivity are given in tables. [ABSTRACT FROM AUTHOR]

In this study, a porous molecularly imprinted electrochemical sensor was successfully fabricated for the selective assay of bisphenol S (BPS) by introducing N-methacryloyl-l tyrosine functional monomer. The molecularly imprinted polymer (MIP)–based sensor (MA-Tyr@MIP/GCE) was prepared via photopolymerization on the glassy carbon electrode and subsequently characterized by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The analytical performance of the sensor was evaluated via CV and differential pulse voltammetry (DPV) measurements. Under the optimized conditions, the rebinding experiment demonstrated that the peak current of the porous MIP-based sensor obviously decreased with the increase of BPS concentration in the concentration range of 1–10 fM. Therefore, the detection limit was determined as 0.171 fM. It should be underlined that MA-Tyr@MIP/GCE exhibited high sensitivity and excellent selectivity because MA-TyrMA-Tyr@MIP/GCE sensor has a higher imprinting factor (IF) toward BPS in respect to competitive analogs, i.e., bisphenol A, bisphenol B, and bisphenol F. The practical application of the sensor also showed good reproducibility and stability for the detection of BPS in human serum and water samples. These results showed MA-Tyr@MIP/GCE successfully applied for the selective recognition of BPS in biological and water samples with high sensitivity and excellent selectivity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Sorafenib (SOR) is a multikinase inhibitor anticancer drug that is used in treating non-small cell lung cancer. In this work, we focused on developing nanomaterial-supported smart porous interfaces by following the molecular imprinting approach for the selective determination of SOR. Determination-based studies in the literature for SOR are limited, and they are chromatographic techniques-based; hence, there is a need in the literature to elaborate the selective and sensitive analysis/monitoring of SOR in both biological and pharmaceutical samples with more studies. The results showed that adding ZnO NPs enhanced the signal five times compared to the solo molecularly imprinted polymer (MIP). Under the optimized conditions, ZnO/AMPS@MIP-GCE showed a linear response in the concentration range between 1.0 × 10−12 and 1.0 × 10−11 M with LOD and LOQ values of 2.25 × 10−13 M and 7.51 × 10−13 M, respectively, in the serum sample. The selectivity study was conducted against common cations, anions, and compounds such as dopamine, paracetamol, ascorbic acid, and uric acid. Also, the imprinting factor (IF) analysis was performed on selected drug substances having structural similarities to SOR and the relative IF values of regorafenib, leflunomide, teriflunomide, nilotinib, axitinib, and dasatinib indicated the selectivity of the developed sensor for SOR. Finally, ZnO/AMPS@MIP-GCE was implemented to determine SOR in the spiked commercial human serum samples and tablet dosage form with bias% between −0.43 and + 0.66. This study is the first electrochemical study for the determination of SOR, and thanks to the ZnO NPs supported MIP sensor, it stands out in terms of both high sensitivity and superior selectivity. Also, this designed sensor provides controlled orientation of the template and complete removal of templates in a one-step process, allowing extremely low detection and quantification limits. [Display omitted] • First nanoparticle supported-MIP sensor for Sorafenib determination. • Accurate and effective analysis in biological and pharmaceutical samples. • High sensitivity and superior selectivity thanks to MIP. [ABSTRACT FROM AUTHOR]

Lack of timely detection or proper monitoring of diseases is still one of the most important causes of death. Developing a portable device that is small, easy to use, and can follow various parameters and factors similar to a portable laboratory is crucial for rapidly diagnosing diseases. Electroanalytical methods stand out among other methods with their easy application, low cost, high sensitivity, and ease of use. Nanomaterials are valuable materials for point-of-care (POC) diagnostics because of their excellent chemical, electrical, electrocatalytic, and physical features. This review overviews the most significant studies on electrochemical POC diagnostics using Mxenes in the last five years. Thanks to this comprehensive review, the researchers will gain an overview of sensitive, selective, low cost and effective analysis methods for electrochemical analysis. Detailed information will be given on how selectivity and sensitivity can be improved in Mxenes-based electrochemical POC sensor studies. Recent studies in this review will be discussed in detail in terms of novel diagnostic devices. Researchers will also find various experimental parameters and the methods used in the electrochemical analysis. In addition, this review will provide great convenience to researchers in finding up-to-date resources for electroanalytical analysis. • MXenes are 2D nanomaterials that exhibit significant electrical, optical, and mechanical properties as well as a unique basic composition. • The effective development of MXene nanomaterials to create advanced sensors with high selectivity and sensitivity will make a crucial contribution to medical care. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electroanalytical behavior of leflunomide (LEF) was investigated in detail using the p(ANI-o-PD)@MIP/GCE sensor. • p(ANI-o-PD)@MIP/GCE sensor gave a linearly response between 1.0 and 10 fM with a LOD of 0.291 fM for the determination of LEF. • Analytical validation parameters were obtained for p(ANI-o-PD)@MIP/GCE. • The sensor was able to determine LEF in serum samples and pharmaceutical dosage form. This study includes the electrochemical analysis of leflunomide (LEF), used in the treatment of rheumatoid arthritis, with a molecularly imprinted polymer (MIP) based sensor using different electroanalytical methods. In the design of MIPs, the choice of functional monomer is an important step in terms of the stability of the sensor. Based on the computational approach in this study, ortho -phenylenediamine (o -PD) was chosen as a functional monomer based on the comparison of interaction energies (ΔE) between LEF and monomers, aniline (ANI) was chosen as a platform to develop MIP-based sensor. Morphological characterization of the developed p(ANI- o -PD)@MIP/GCE sensor was performed using Raman spectroscopy, surface electron microscopy (SEM), contact angle measurements, and electrochemical techniques. Quantitative analysis of LEF was performed using differential pulse voltammetry. Results showed that the p(ANI- o -PD)@MIP/GCE sensor has high selectivity and sensitivity. Under optimum conditions, the linear range was found to be 1 – 10 fM (r = 0.998) and the detection limit to be 0.291 fM. Also, the sensor was applied to pharmaceutical dosage form and serum samples to detect LEF, and satisfactory recovery results of 99.46% and 99.15% were obtained. Finally, the p(ANI- o -PD)@MIP/GCE sensor was evaluated using a non-imprinted polymer (NIP)-based electrochemical sensor. The proposed sensor with good reproducibility was effectively implemented for selective and sensitive detection of LEF in pharmaceutical and human serum samples. These results show that the molecular imprinting approach in detecting LEF is a highly effective technique in the potential of the newly developed sensor. [ABSTRACT FROM AUTHOR]

Using various methods and substances for improving performance in sports is described as doping. Doping has always been a critical issue in terms of ethical and medical reasons. In this regard, the World Anti-Doping Agency (WADA) is making significant efforts. Anabolic agents (androsterone, testosterone, oxymetholone, clenbuterol, etc.), hormones, and metabolic modulators (raloxifene, meldonium, theophylline etc.) are prohibited by WADA. Therefore, sensitive and selective determination of these substances in biological and pharmaceutical samples is highly significant. Electroanalytical techniques stand out as sensitive, reliable, fast, and eco-friendly options over other methods. Nanomaterials are stable, catalytic, and easily applicable modification materials. In this context, numerous nanomaterials are used to enhance the performance of the electrochemical sensors. This review examines the latest studies between 2011 and 2021 based on the nanomaterial-based electrochemical sensors as highly sensitive, selective, user-friendly, low-cost, and rapid tools for the determination of selected prohibited substances (hormones, metabolic modulators, and anabolic agents) in biological, pharmaceutical and food samples. • Hormones, metabolic modulators, and anabolic agents are doping substances prohibited by World Anti-Doping Agency. • Nanomaterial-based electrochemical sensors provide sensitive, selective, user-friendly, low-cost, and rapid analysis. • Latest studies on the nanomaterial-based electrochemical sensors for the analysis of selected substances. [ABSTRACT FROM AUTHOR]

In this study, a novel, fast, selective, and sensitive molecularly imprinted polymer (MIP)-based electrochemical sensor was developed to determine axitinib (AXI) at low concentrations in pharmaceutical dosage forms and human serum. The newly developed MIP-based sensor (MIP@o-PD/GCE) was designed through electropolymerization of functional monomer o -phenylenediamine (o-PD) in the presence of a template molecule AXI, on a glassy carbon electrode (GCE) using cyclic voltammetry. Differential pulse voltammetry and electrochemical impedance spectroscopy (EIS) techniques were employed for removal and rebinding processes, optimization of conditions, as well as for performance evaluation of MIP@o-PD/GCE using [Fe(CN) 6 ]3−/4– as the redox probe. Under the optimum experimental conditions, MIP@o-PD/GCE shows a linear response toward AXI in a range of 1 × 10−13 M − 1 × 10−12 M. The limit of the detection value of MIP@o-PD/GCE was found as 0.027 pM while the limit of the quantification was obtained as 0.089 pM, respectively. To demonstrate the applicability and validity of the developed sensor, it was successfully applied to tablet dosage form and human serum sample. The selectivity of the sensor was qualified by comparing the binding of AXI, erlotinib, dasatinib, nilotinib, and imatinib, which are similarly structured and in the same group of anticancer drugs. MIP@o-PD/GCE sensor showed a significant selectivity toward AXI. The non-imprinted polymer (NIP) based GCE was prepared and used to control the analytical performance of the MIP-based electrochemical sensor. [Display omitted] • The first MIP study for ultra-trace assay of anti-cancer drug Axitinib. • The MIP@o-PD/GCE sensor exhibits a linear response between 0.1 pM and 1 pM AXI with LOD of 0.027 pM. • Application of AXI in pharmaceutical dosage form and human serum sample. [ABSTRACT FROM AUTHOR]

Azo-dyes such as Allura Red, Carmoisine, Amaranth, Sunset Yellow (SY), Brilliant Blue, Tartrazine (Tz), etc., are popular as food coloring agents due to their low cost and stability. SY and Tz are the most used members of this group of dyes since they have similar colors and are usually used together in food products. Despite their advantageous industrial use, they exhibit a risk toxicity profile with adverse effects such as allergy, asthma, carcinogenicity, genotoxicity, cytotoxicity, anxiety, etc. Therefore, the United States Food and Drug Administration (FDA) and European Food Safety Authority (EFSA) regulate the permissions for using these compounds to provide safe food products for consumers and prevent adverse effects both short and long-term. Considering all of these, for the analysis of azo toxic dyes, highly sensitive, low-cost, simple, and rapid sensors are necessary. Electrochemical nanosensors, which combine the unique features of electrochemistry and nanotechnology, are devices with all these advantages and are widely used for the determination of azo dyes. SY and Tz step forth as the most used food dyes in the class of azo-toxic dyes. They are often preferred together in food products, increasing the occurrence and exposure risk. Therefore, the analysis of Sunset Yellow and Tartrazine in food products has significant importance. In this review, the latest nanomaterial-based approaches for the electrochemical sensors on the analysis of SY and Tz in food samples were evaluated in terms of used nanomaterials and applied food samples. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The first MIP-based electrochemical sensor for the determination of PLB. • Great selectivity, very low LOD values, good repeatability, and reproducibility. • Highly accurate application in biological and pharmaceutical samples. In this research, a molecularly imprinted polymer (MIP)-based electrochemical sensor was developed for the first time to determine palbociclib (PLB), an oral, selective Cyclin Dependent Kinase (CDK4 and CDK6) inhibitor used in the treatment of breast cancer. Acrylamide (ACR) was selected as the functional monomer to fabricate the proposed sensor (ACR-PLB-MIP/GCE), and polymerization was performed by photopolymerization. To improve the efficiency of the MIP-based electrode for PLB measurement, several factors, including monomer ratio, removal time, removal agent, and rebinding time, were carefully optimized. Under optimal conditions and using the differential pulse voltammetry (DPV) technique, the limit of detection (LOD) of 1.35 × 10−12 M and the limit of quantification (LOQ) of 4.48 × 10−12 M were calculated for PLB analysis using ACR-PLB-MIP/GCE in standard solution. Application of the ACR-PLB-MIP/GCE sensor to commercial serum samples resulted in LOD and LOQ values of 3.33 × 10−12 M and 1.11 × 10−11 M, respectively. The sensor was also applied to the tablet sample for the detection of PLB and a satisfactory RSD% (0.95) was obtained. The results of interference studies confirmed the high selectivity of the electrode for PLB analysis. These results clearly demonstrated that the molecular imprinting approach for the detection of PLB in the novel sensor system is a highly efficient approach. [ABSTRACT FROM AUTHOR]

Ion-selective electrodes have become the largest and most widely utilized category of electrochemical sensors since the end of the last century, marked by the introduction of solid-contact electrodes. Ongoing research in potentiometric sensors predominantly focuses on innovating new variations or emerging trends of solid contact to yield devices with improved analytical parameters. Many advanced ion selective electrodes (ISEs) have proven to be highly effective in pharmaceutical practical applications. The inherent advantages of ISEs, including their simplicity, affordability, rapid analysis, precision and accuracy, on-site monitoring, acceptable limit of detection (LOD), wide linear range, and selectivity, make them promising candidates for pharmaceutical analysis. While numerous review articles have been published in recent years, addressing topics such as membrane materials, ionophores, functional materials, and applications in various fields, there seems to be a gap in the literature when it comes to a comprehensive review summarizing the extensive utilization of various solid-contact ion-selective electrodes (SC-ISEs) in pharmaceuticals and biomedical applications, based on our current knowledge. Therefore, this review article aims to fill this gap by focusing on advancements made in the past six years in the detection capabilities of SC-ISEs within pharmaceuticals. This review article provides an overview of the traditional and modified various types of SC-ISC viz carbonaceous, metal/metal oxide, composite based, and polymer-based ISE used for pharmaceutical analysis with their detection limit, stability, recovery, and target matrix sensing. Introduction of new materials viz. MXene and other polymeric materials give new dimensions in the future to enhance the selectivity and sensitivity of ISEs. Sensors developed with ISE have extraordinary potential to reduce the LOD of different surface modifications down to the pM level. They have the ability to perform analyses directly on the sample without requiring pretreatment in diagnostic laboratories. The intent is to provide an up-to-date and thorough overview of the progress made in the development of these electrodes, enhancing performance and accessibility in this specific area of research. [ABSTRACT FROM AUTHOR]

Clozapine (CLO) is an atypical antipsychotic drug indicated for the treatment of schizophrenia. The treatment effectiveness of CLO is better than that of other atypical antipsychotics, and it has the advantage of being able to determine its effectiveness by measuring its concentration in the patient's blood. Thus, sensitive, selective, and accurate determination of CLO in blood is highly significant for treatment monitoring. This study describes the design and fabrication of a molecularly imprinted polymer (MIP)-based electrochemical sensor for CLO determination. This is the first MIP-based electrochemical application in the literature for CLO determination. Employing the thermal polymerization approach, the MIP was formed on the glassy carbon electrode (GCE) using CLO as the template, trans -3-(3-Pyridyl)acrylic acid (3,3-TA) as the functional monomer, and the support of zinc oxide nanoparticles (ZnO NPs). Elaborate characterizations in terms of surface morphology and electrochemistry were performed via scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) methods. An indirect approach was employed to determine CLO in standard solution, real human biological samples, and tablet formulation, using 5 × 10−3 M [Fe(CN) 6 ]3–/4– solution as the redox probe. The limit of detection (LOD) values for the standard solution and serum sample were calculated as 2.9 × 10−11 M and 6.01 × 10−12 M, respectively. These values and recovery studies confirmed the sensor's sensitivity and feasibility. The measurements in the presence of similarly structured compounds (olanzapine and quetiapine fumarate) verified the sensor's superior selectivity. Moreover, the developed sensor's performance was compared and verified using an LC-MS/MS method using the student's t-test and F-test. [Display omitted] • Highly selective application of an electrochemical MIP sensor for CLO determination. • Successful application in real patient serum samples and tablet formulation. • Performance comparison of the MIP-based electrochemical method with LC-MS/MS. • The student's t-test and F-test confirmed the sensor's performance. [ABSTRACT FROM AUTHOR]

Phytoestrogens are non-steroidal estrogens produced from plants that can bind with the human body's estrogenic receptor site and be used as a substitute for maintaining hormonal balance. They are mainly classified as flavonoids, phenolic acids, lignans, stilbenes, and coumestans; some are resocyclic acids of lactones, which are mycotoxins and not natural phytoestrogen. Phytoestrogens have many beneficial medicinal properties, making them an important part of the daily diet. Electrochemical sensors are widely used analytical tools for analysing various pharmaceuticals, chemicals, pollutants and food items. Electrochemical sensors provide an extensive platform for highly sensitive and rapid analysis. Several reviews have been published on the importance of the biological and medicinal properties of phytoestrogens. However, this review provides an overview of recent work performed through electrochemical measurements with electrochemical sensors and biosensors for all the classes of phytoestrogens done so far since 2019. • Phytoestrogens, their classification and sources have been discussed. • Electrochemical sensors for phytoestrogens in food samples and dietary supplements. • First comprehensive review of the electrochemical assay of dietary phytoestrogens. • The advantages of new generation electrochemical sensors for phytoestrogens. • Point-of-care testing for rapid test and home test for phytoestrogens in food samples. [ABSTRACT FROM AUTHOR]

Quercetin (QUE) is a powerful antioxidant and one of the common phenolic compounds found in plants, vegetables, and fruits, which has shown many pharmacological activities. The complex nature of the matrix in which QUE is found and its importance and potential uses in diverse applications force the researchers to develop selective and sensitive sensors. In the present work, a novel molecularly imprinted polymer (MIP)-based electrochemical sensor was fabricated for the selective and sensitive determination of the QUE in plant extracts and food supplements. Tryptophan methacrylate (TrpMA) was chosen as the functional monomer, whereas the photopolymerization (PP) method was applied using a glassy carbon electrode (GCE). Electrochemical and morphological characterizations of the developed sensor (TrpMA@QUE/MIP-GCE) were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The linear range of the developed sensor was determined to be in the range of 1.0–25 pM, while the limit of detection (LOD) was calculated to be 0.235 pM. In conclusion, The TrpMA@QUE/MIP-GCE sensor might be classified as a promising platform for selective and sensitive determination of QUE not only in plant extracts but also in commercial food supplements because of its reliability, reproducibility, repeatability, stability, and fast response time. [Display omitted] • MIP-based electrochemical determination of antioxidant phenolic compound QUE. • Highly selective application in plant extracts (fruit, stem, leaf, and flower). • Accurate determination of QUE content in commercial herbal supplements. • Superior selectivity, rapid, and easy analysis compared to other studies. [ABSTRACT FROM AUTHOR]