Trends in electrochemical nanosensors for the analysis of antioxidants

Antioxidants play a very critical role in many biological processes in which free radicals are present. The physiological part of these compounds prevents damage to cellular components from arising because of chemical reactions involving free radicals. Oxidation mechanisms appear continuously in living metabolism, and reactive oxygen species are taken from outside step-up oxidation events. Many attempts have been made rapid, economical, and user-friendly analytical approaches for detecting and determining antioxidant capacity in recent years. Electrochemical techniques offer an alternative and powerful strategy for determining antioxidant content as they allow simple and inexpensive detection. This review discusses information about antioxidants, their classification, mechanism of action, ...

Antifibrotik İlaç Pirfenidonun Tayinine Yönelik Elektrokimyasal Çalışmalar ve Uygulamaları

Akciğer hastalıkları, yüksek mortaliteye sahip, dünyanın ciddi sağlık sorunlarından biridir. İdiyopatik pulmoner fibrozis, esas olarak yaşlı yetişkinlerde ortaya çıkan ve akciğerlerde görülen, nedeni bilinmeyen, kronik bir hastalık olarak tanımlanır. Pirfenidon (5−metil−1−fenil−2−[1H] −piridon), yan etkileri az olan bir antifibrotik ajandır. Bu tez çalışmasında Pirfenidon'un tayini için ilk defa elektrokimyasal yöntem geliştirilmiştir. Pirfenidon'un elektrokimyasal davranışını incelemek için yalın elektrot ile daha hassas tayini için moleküler baskılanmış nanosensör ile çalışmalar yapılmıştır. Çalışma elektrodu olarak camsı karbon elektrot (CKE) kullanılmıştır. Pirfenidon'un elektrokimyasal davranışı için yalın CKE ile dönüşümlü voltametri (DV), diferansiyel puls voltametris...

Acyl thiourea derivatives: Versatile tools for chemosensing and heavy metal remediation

Selcuk, Ozge | Nangyallai, Azizi | Nural, Yahya

The increasing environmental pollution, particularly from heavy metals and hazardous anions, poses a significant threat to global health and ecosystems. The unique structural features of these compounds, including multiple coordination sites, enhanced electron density, favorable steric effects, and stabilized metal-ligand complexes, enable their effective application in both chemosensing and heavy metal remediation. As chemosensors, acyl thiourea derivatives exhibit high sensitivity and selectivity in detecting various cations, anions, and neutral species, making them valuable tools for in situ environmental analysis. Additionally, their ability to efficiently adsorb heavy metals like Cu2+, Hg2+, Cd2+, U4+, Pb2+, Pt4+, and Pd2+, along with the removal of Cl− from acidic wastewater, demonst...

Recent advances in electrochemical sensing devices for pharmaceutical and biomedical diagnosis

The most recent advancements in electrochemical sensors created to track drugs and biomarkers used in medication and disease detection are summarized in this chapter. New sensors continue to be developed using various chemical or biological detecting materials. Additionally, mass production technology, which is excellent for the microelectronics industry, enables the development of exceedingly compact, replicable, and inexpensive (disposable) sensor devices. These devices are paired with compact, user-friendly instrumentation powered by microprocessors. Pollution control will surely benefit greatly from ‘smart’ sensors and other advancements in selective and stable identification elements, such as distant electrodes, molecular devices, multi-parameter sensor arrays, micromachining, and nan...

Analytical Methods for Determination of Antiviral Drugs in Different Matrices: Recent Advances and Trends

Viruses are the main pathogenic substances that cause severe diseases in humans and other living things. They are among the most common microorganisms, and consequently, antiviral drugs have emerged to prevent and treat viral infections. Antiviral drugs are an essential drug group considering their prescription and consumption rates for different diseases and indications. Therefore, it is crucial to develop accurate and precise analytical methods to detect antiviral drugs in various matrices. Chromatographic techniques are used frequently for the quantification purpose since they allow simultaneous determination of antivirals. Electrochemical methods have also gained importance since the analysis can be performed quickly without the need for pretreatment. Spectrophotometric and spectrofluo...

Development of Nanoparticle-Modified Ultramicroelectrodes and Their Electroanalytical Application

An ultramicroelectrode is an electrode whose characteristic dimensions are smaller than 25 μm. They have been used in electrochemistry for the last 30 years and can be used in studying extremely small sample volumes. Due to these advantages, ultramicroelectrodes have revolutionized electrochemical applications and methodologies. They have also transformed the time/space accessibility of experimentation. Nanomaterials are materials whose dimensions are at the nanometer scale (1–100 nm) or assembled at this range. When compared to conventional materials the structure and properties of nanomaterials are essentially changed. They show chemical, physical, and electronic properties that are not seen in other materials or even materials from which the nanoparticles were prepared. Nanomaterials ar...

Layer-by-layer modification strategies for electrochemical detection of biomarkers

In the last decades, the use of electrochemical and electrode modification-based biosensors has aroused great research interest in widely different applications such as medical diagnostics, drug analysis, environmental monitoring, food analysis, and biochemical analysis. Moreover, the use of various nanomaterials for electrode modifications and the production of these modifications based on the layer-by-layer film deposition techniques have provided significant advantages in the production of stable and sensitive sensors that provide a large surface area. In this review, the applications of electrochemical methods developed for the determination of major biomarkers that are important in the diagnosis of different diseases are discussed. In three main categories, diseases and related biomar...

Phosphodiesterase-3 Enzyme Inhibitor Drug Milrinone Interaction with DNA and HSA: Electrochemical, Spectroscopic and Molecular Docking

In this study, the interaction between the phosphodiesterase-3 enzyme inhibitor drug milrinone and biomolecules was investigated by electrochemical, fluorescence spectroscopy, and molecular docking studies for the first time. The interaction between milrinone and biomolecules was investigated according to the decrease in deoxyguanosine oxidation signals of milrinone and calf thymus double-stranded deoxyribonucleic acid (ct-dsDNA) by cyclic voltammetry and differential pulse voltammetry. In fluorescence spectroscopy studies, a competitive study was conducted on ct-dsDNA by adding a well-known fluorescent methylene blue and ct-dsDNA solution. The fluorescent results showed that milrinone had a higher affinity for ct-dsDNA binding compared to methylene blue. Interaction studies show that milr...

Electrochemical determination of phosphodiesterase-3 enzyme inhibitor drug Milrinone with nanodiamond modified paste electrode

Milrinone (MIL) is an essential cardiac inotrope drug for cardiovascular disease. In this study, a simple nanosensor based on a nanodiamond carbon paste electrode modified with flower-like ZnO particles was developed to determine MIL electrochemically rapidly and accurately. The flower-like ZnO nanoparticles were synthesized by a simple and cheap sonochemical method. The structure and morphology of the ZnO nanoparticles were investigated by Fourier transform infrared spectrometer and scanning electron microscopy. The electron transfer properties of bare carbon paste electrodes, nD@CPE, CPE/ZnO, and flower-like carbon paste electrodes modified with ZnO and decorated with nanodiamonds (nD@CPE/ZnO) were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). ...

Polymeric Nanofibers as Electrodes for Sensors

The chapter is meant to examine the performance of electrodes blended with nanofibers. This study concerns the synthesis, characterization, and applications of electrodes and polymeric nanofibers. Electrospinning is a basic, simple, and adaptable strategy for creating submicron and nano size filaments. Owing to their enormous surface territory and permeable design, electrospun nanofibers can be utilized widely in biomedical, ecological, defensive attire, and sensors applications. Nano filaments of micron measurement and various compound organizations were prepared. Sensors are set up instruments of synthetic investigation utilized in both electrochemical and optical detecting modes. They permit understanding into ion concentrations in different examples, offering reliable performance. One ...

Rapid determination of uracil in biological fluids at mercury thin film electrode for early detection of potential 5-fluorouracil toxicity due to dihydropyrimidine dehydrogenase deficiency

Determination of plasma uracil was reported as a method for evaluation of Dihydropyrimidine dehydrogenase (DPD) activity that is highly demanded to ensure the safe administration of 5-fluorouracil (5-FU)-based therapies to cancer patients. This work reports the development of a simple electroanalytical method based on adsorptive stripping square wave voltammetry (AdSWV) at mercury film-coated glassy carbon electrode (MF/GCE) for the highly sensitive determination of uracil in biological fluids that can be used for diagnosis of decreased DPD activity. Due to the formation of the HgII–Uracil complex at the electrode surface, the accuracy of the measurement was not affected by the complicated matrices in biological fluids including human serum, plasma, and urine. The high sensitivity of the d...

Electroanalytical Investigation and Simultaneous Determination of Etodolac and Thiocolchicoside at a Non-Modified Glassy Carbon Electrode in Anionic Surfactant Media

In this study, a differential pulse voltammetry method was designed for the simultaneous determination of etodolac and thiocolchicoside in a tablet dosage form. This method is a sensitive, costless and reproducible one initially designed for the simultaneous determination of etodolac and thiocolchicoside using bare/unmodified glassy carbon electrode in the presence of sodium dodecyl sulfate. At optimized conditions, the method showed linear responses with etodolac and thiocolchicoside concentration in the range of 1 mu M to 80 mu M. The limits of detection and quantification were calculated as 0.11 mu M and 0.38 mu M for etodolac and 0.20 mu M and 0.67 mu M for thiocolchicoside, respectively.

Fundamentals of Aptamers and Aptamers-Based Biosensors

Antibodies or enzymes have long dominated the field of sensors and analysis, based on their most effective capture capacity for many target molecules as biorecognition. Because of this, immunoassay has developed into one of the best platforms for biosensors, including clinical diagnostics. Although widely acknowledged as a conventional biosensor for identifying various analyte targets, antibody- or enzyme-based platforms are nevertheless limited in their recognition of many targets, such as hazardous small compounds or non-immunogenic target analytes. Additionally, designing for these compounds is difficult. Aptamers have drawn a lot of attention as an antibody competitor since their initial discovery in 1990 due to their several advantages over antibodies. The fact that aptamer's tar...

Nanomaterials and signal amplification toward foodborne pathogen biosensor

Foodborne pathogens pose important risks to both human health and food safety worldwide. Contamination of foodborne pathogens negatively affects human and environmental health and causes enormous economic losses. Therefore, accurate, rapid, and sensitive detection is a critical step to ensure food safety. Traditional methods, including culture and colony counting, immunology-based, and polymerase chain reaction-based methods for detecting foodborne pathogens, are often cumbersome and cannot provide the desired level of sensitivity. While the cost increases due to time-consuming sample preparation procedures, these methods require bulky equipment that allows analysis only under laboratory conditions. Biosensors are valuable because of their ease of use, portability, relatively low cost, and...

Designing a selective electrochemical nanosensor based on molecularly imprinted polymer for detection of pirfenidone

In this study, an electrochemical determination of pirfenidone(PIR), an antifibrotic drug, was developed for the first time with a bare glassy carbon electrode(GCE) and a molecularly imprinted polymer(MIP)-based nanosensor. A molecularly imprinted polymer(MIP) incorporating o-phenylenediamine(o-PD), chitosan(CHIT), ionic liquid(IL), and diamond nanoparticles(DiaNPs) was utilized to modify a glassy carbon electrode(GCE), developing a stable and selective electrochemical nanosensor(MIP/CHIT@IL@DiaNPs/GCE) for PIR detection. The designed MIP/CHIT@IL@DiaNPs/GCE was characterized by electrochemical impedance spectroscopy(EIS), cyclic voltammetry(CV), scanning electron microscopy(SEM) and atomic force microscopy(AFM). The [Fe(CN)6]3−/4− redox couple was used as a probe to characterize the nanose...

Surfactant-Based Sensors in Chemical and Biochemical Detection

Surfactants are compounds that have both hydrophilic and hydrophobic properties due to their structures and are widely used in many industrial products, daily life, and many electrochemical studies. The hydrophobic parts usually consist of long hydrocarbon chains, while the hydrophilic parts can contain many different functional groups. These substances, also called surface active agents, reduce the surface tension in their aqueous solutions. For this reason, in addition to their use as emulsifiers, they also have antibacterial properties, are solubilizers, and are used as detergents. Although the use of synthetic surfactants is common in general, biosurfactants, which are called green surfactants, are also being studied intensively. In this chapter, the role of surfactants in electrochemi...