Electrochemical Chemically Based Sensors and Emerging Enzymatic Biosensors for Antidepressant Drug Detection: A Review

Major depressive disorder is a widespread condition with antidepressants as the main pharmacological treatment. However, some patients experience concerning adverse reactions or have an inadequate response to treatment. Analytical chromatographic techniques, among other techniques, are valuable tools for investigating medication complications, including those associated with antidepressants. Nevertheless, there is a growing need to address the limitations associated with these techniques. In recent years, electrochemical (bio)sensors have garnered significant attention due to their lower cost, portability, and precision. Electrochemical (bio)sensors can be used for various applications related to depression, such as monitoring the levels of antidepressants in biological and in environmental samples. They can provide accurate and rapid results, which could facilitate personalized treatment and improve patient outcomes. This state-of-the-art literature review aims to explore the latest advancements in the electrochemical detection of antidepressants. The review focuses on two types of electrochemical sensors: Chemically modified sensors and enzyme-based biosensors. The referred papers are carefully categorized according to their respective sensor type. The review examines the differences between the two sensing methods, highlights their unique features and limitations, and provides an in-depth analysis of each sensor.

Competitive Formation Zones in Carbon Nanotube Float-Catalysis Synthesis: Growth in Length vs. Growth Suppression

Catalytic synthesis of carbon nanotubes (CNT) produces numerous various byproducts such as soot, graphite platelets, catalyst nanoparticles, etc. Identification of the byproduct formation mechanisms would help develop routes to more selective synthesis of better carbon-based materials. This work reports on the identification of the formation zone and conditions for rather unusual closed multishell carbon nanocapsules in a reactor for float-catalysis synthesis of longer CNT. Structural investigation of the formed nanocapsule material along with computational fluid dynamics (CFD) simulations of the reactor suggested a nanocapsule formation mechanism, in which CNT embryos are suppressed in growth by the in-reactor turbulence. By means of TEM and FFT investigation, it is found that differently oriented single crystals of γ-Fe₂O₃, which do not have clear connections with each other, determine a spherical surface. The carbon atoms that seep through these joints do not form crystalline graphite layers. The resulting additional product in the form of graphene-coated (γ-Fe/Fe₃C)/γ-Fe₂O₃ nanoparticles can be a lightweight and effective microwave absorber.

Recent advancements in enzyme-incorporated nanomaterials: Synthesis, mechanistic formation, and applications

Over the past decade, nanotechnology has been developed and employed across various entities. Among the numerous nanostructured material types, enzyme-incorporated nanomaterials have shown great potential in various fields, as an alternative to biologically derived as well as synthetically developed hybrid structures. The mechanism of incorporating enzyme onto a nanostructure depends on several factors including the method of immobilization, type of nanomaterial, as well as operational and environmental conditions. The prospects of enzyme-incorporated nanomaterials have shown promising results across various applications, such as biocatalysts, biosensors, drug therapy, and wastewater treatment. This is due to their excellent ability to exhibit chemical and physical properties such as high surface-to-volume ratio, recovery and/or reusability rates, sensitivity, response scale, and stable catalytic activity across wide operating conditions. In this review, the evolution of enzyme-incorporated nanomaterials along with their impact on our society due to its state-of-the-art properties, and its significance across different industrial applications are discussed. In addition, the weakness and future prospects of enzyme-incorporated nanomaterials were also discussed to guide scientists for futuristic research and development in this field.

Recent Advances in Electrochemical Biosensors Based on Enzyme Inhibition for Clinical and Pharmaceutical Applications

A large number of enzyme inhibitors are used as drugs to treat several diseases such as gout, diabetes, AIDS, depression, Parkinson's and Alzheimer's diseases. Electrochemical biosensors based on enzyme inhibition are useful devices for an easy, fast and environment friendly monitoring of inhibitors like drugs. In the last decades, electrochemical biosensors have shown great potentials in the detection of different drugs like neostigmine, ketoconazole, donepezil, allopurinol and many others. They attracted increasing attention due to the advantage of being high sensitive and accurate analytical tools, able to reach low detection limits and the possibility to be performed on real samples. This review will spotlight the research conducted in the past 10 years (2007-2017) on inhibition based enzymatic electrochemical biosensors for the analysis of different drugs. New assays based on novel bio-devices will be debated. Moreover, the exploration of the recent graphical approach in diagnosis of reversible and irreversible inhibition mechanism will be discussed. The accurate and the fast diagnosis of inhibition type will help researchers in further drug design improvements and the identification of new molecules that will serve as new enzyme targets.