Ultrasensitive electrochemical sensor for the detection of carbamazepine based on gadolinium vanadate nanostructure decorated functionalized carbon nanofiber nanocomposite

A ratiometric electrochemical sensor for antiepileptic drug of carbamazepine based on electroactive Ni2+-terephthalic acid MOF

Carbamazepine (CBZ), an anticonvulsant and mood stabilizer used extensively for epilepsy, requires a reliable and sensitive monitoring assay for assessing and optimizing the dosage administered to epileptic patients. In this work, spherical nickel-based metal-organic framework materials (Ni-MOFs) consisting of nanosheets were synthesized and cast on glassy carbon electrode (GCE) to prepare a novel ratiometric CBZ electrochemical sensor. The electrochemical test results showed that the Ni-MOF-based sensor had a pair of reversible redox peaks at +0.54 V and +0.39 V, respectively, originating from the Ni3+/Ni2+ pair. Meanwhile, CBZ presented an intense irreversible oxidation peak at +1.22 V on the sensor, and its peak current intensity was significantly higher than that on bare GCE and Nafion/GCE. This enhancement can be ascribed to the synergistic effects of the extensive electroactive surface area and the superior electron transfer kinetics of the Ni-MOF, as evidenced by comprehensive physical and electrochemical characterizations. Further, ratiometric sensing detection of CBZ can be achieved by measuring the ratio (R) of oxidation peak currents between CBZ and Ni-MOF, using the Ni-MOF's oxidation peak as the internal reference signal. Under the optimal experimental conditions, the sensor can detect CBZ in the concentration range from 20 to 300 μM with the detection limit as low as 1.03 μM. The recoveries of 94.2-103.3 % were obtained when the sensor was used for the determination of CBZ in serum samples, which demonstrated that the sensor has potential applications in the monitoring of CBZ residues in biological samples.

Electrochemical sensors: Types, applications, and the novel impacts of vibration and fluid flow for microfluidic integration

Electrochemical sensors are part of a diverse and evolving world of chemical sensors that are impacted by high demand and ongoing technological advancements. Electrochemical sensors offer benefits like cost-efficiency, short response time, ease of use, good limit of detection (LOD) and sensitivity, and ease of miniaturization while providing consistent analytical results. These sensors are employed in various fields-such as healthcare and diagnostics, environmental monitoring, and the food industry-to detect bacteria, viruses, heavy metals, pesticides, and more. In this review, we provide a comprehensive overview of electrochemical sensing techniques, with a focus on enhancing sensor performance through the integration of vibration and hydrodynamic flow in microfluidic systems. We present a structured comparison of these methods, utilizing tables to highlight the approaches most effective for performance enhancement. Additionally, we classify various electrochemical sensing applications, offering insights into the practical utilization of these two techniques for lowering the LOD. Finally, we present a comparative analysis of relevant studies, highlighting how hydrodynamic flow and vibration impact the sensing mechanism. We also explore the potential of these techniques to facilitate the development of automated, high-throughput microfluidic platforms, thereby optimizing their functionality and efficiency.

A high-performance aptasensing interface based on pseudo-AuNBs@Ti3C2Tx MXene nanocomposite for non-invasive measurement of carbamazepine in human biofluids

For the first time, a novel aptasensing interface based on smart integration of pseudo-gold nanobons (AuNBs) and Ti3C2Tx MXene is introduced for high selective detection of carbamazepine (CBZ). The large specific surface area achieved from the proposed nanocomposite increases the targeted immobilization of the Apt sequence on the surface via AuNBs as the linkage. It embeds a high-performance grafting platform for trapping CBZ with high sensitivity and accuracy in human biofluids and pharmaceutical formulations. The molecular dynamic (MD) simulation method that exhibits how the Apt binds to CBZ in a conformation-switching assay format from a molecular view is a valid certification for the interaction of CBZ on the developed aptasensing interface. The aptasensor measured CBZ from 1 fM to 100 nM with a superior detection limit (LOD) value of 330 aM compared with other reported CBZ sensors. Due to using biocompatible and non-toxic compounds, consuming low energy and chemicals the greenness of the proposed strategy has been certified by the international scoring system.

A Comprehensive Review of the Recent Developments in the Electroanalytical Methods for the Therapeutic Monitoring of Antiepileptic Drugs

Epilepsy is a serious neurological disease that impacts all facets of a patient's life, including their socioeconomic situation. The failure to identify underlying epileptic signatures in their early stages might result in severe harm to the central nervous system (CNS) and permanent adverse changes to some organs. Therefore, numerous antiepileptic drugs (AEDs) are frequently used to control and treat the frequency of seizures. Since clinical effects and plasma concentration are directly correlated, determining AED levels in various samples has drawn a lot of interest in the optimization of drug doses. In the past several years, various generations of AEDs have appeared, and a variety of techniques have been widely used to analyze AEDs, including HPLC, chromatography, spectrometry, and electrochemical methods such as voltammetric, potentiometric, and others that can help in the analysis of these drugs because of their special benefits, which include quick analysis, high sensitivity, high selectivity, low cost, and dependable results. For the first time, this review article details the most recent advancements in the electrochemical measurement techniques used in the analysis of some of the most effective drugs in the three generations of AEDs in various samples using diverse electrode types, including glassy carbon electrodes (GCE), gold electrodes, pencil graphite electrodes (PGE), and other types. In addition to summarizing their mode of action and side effects. Finally, we will present the prospects for the development of electrochemical platforms for the determination of the next generation of AEDs.

CNT functionalized GdCoBi ternary metal oxide nanocomposite for electrochemical detection of perfluorooctanoic acid and energy storage applications

Perfluorooctanoic acid "Forever Chemical" presents substantial ecological challenges owing to its persistence and resistance to degradation. The study introduces a novel approach by integrating ternary metal oxides-Gd2O3, Co3O4, and Bi2O3 with carbon nanotubes to develop a versatile electrode material, CNT@GdCoBi NCs, which demonstrates dual functionality as both an electrochemical sensor for PFOA and a component for energy storage devices. The electrode exhibits outstanding electrochemical sensing performance, with a detection limit for PFOA of 4.9 ppb. Interference tests reveal the electrode's high selectivity for PFOA, with a tolerance limit of ≤ 5 %. Practical application on various fruits, vegetables, and water samples shows an average relative standard deviation (%RSD) between 4.8 % and 5.6 %, underscoring the practical effectiveness of the CNT@GdCoBi NCs electrode. Furthermore, the CNT@GdCoBi NCs exhibit remarkable supercapacitor performance, achieving a specific capacitance of 1197 F/g at 2 A/g, which is 1.5 times higher than that of GdCoBi NCs. At a current density of 2 A/g, the symmetric supercapacitor device demonstrates a specific capacitance of 269 F/g, along with a high energy density of 52 Wh/kg at a power density of 500 W/kg. Additionally, the CNT@GdCoBi NCs electrode maintains good durability, retaining 94 % of its capacitance after 10,000 cycles.

Determination of Antiepileptics in Biological Samples-A Review

Epilepsy remains a disease that affects many people around the world. With the development of new drugs to treat this condition, the importance of therapeutic drug monitoring continues to rise and remains a challenge for the medical community. This review article explores recent advances in the detection of antiepileptic drugs across various sample types commonly used for drug monitoring, with a focus on their applications and impact. Some of these new methods have proven to be simpler, greener, and faster, making them easier to apply in the context of therapeutic drug monitoring. Additionally, besides the classic use of blood and its derivatives, there has been significant research into the application of alternative matrices due to their ease of sample collection and capacity to reflect drug behavior in blood. These advances have contributed to increasing the efficacy of therapeutic drug monitoring while enhancing its accessibility to the population.

Recent Advances on Electrochemical Sensors for Detection of Contaminants of Emerging Concern (CECs)

Contaminants of Emerging Concern (CECs), a new category of contaminants currently in the limelight, are a major issue of global concern. The pervasive nature of CECs and their harmful effects, such as cancer, reproductive disorders, neurotoxicity, etc., make the situation alarming. The perilous nature of CECs lies in the fact that even very small concentrations of CECs can cause great impacts on living beings. They also have a nature of bioaccumulation. Thus, there is a great need to have efficient sensors for the detection of CECs to ensure a safe living environment. Electrochemical sensors are an efficient platform for CEC detection as they are highly selective, sensitive, stable, reproducible, and prompt, and can detect very low concentrations of the analyte. Major classes of CECs are pharmaceuticals, illicit drugs, personal care products, endocrine disruptors, newly registered pesticides, and disinfection by-products. This review focusses on CECs, including their sources and pathways, health effects caused by them, and electrochemical sensors as reported in the literature under each category for the detection of major CECs.

ZIF-67-Derived Co/N-Doped Carbon-Functionalized MXene for Enhanced Electrochemical Sensing of Carbendazim

Herein, ZIF-67-derived Co and N-doped carbon (Co/NC) particle-modified multilayer MXene (MXene@Co/NC) was developed as remarkable electrode material for carbendazim (CBZ) detection. MXene as a substrate provides an excellent conductive framework and plentiful accessibility sites. Co/NC particles embedding in MXene can not only prevent the interlayer stacking of MXene but also contribute a great deal of metal catalytic active sites and finally improve the adsorption and catalytic properties of the composite. Accordingly, the MXene@Co/NC electrode displays excellent electrocatalytic activity toward CBZ oxidation. Experimental parameters such as pH value, accumulation time, MXene@Co/NC modification volume and constituent materials' mass ratios were optimized. Under optimal conditions, the as-prepared sensor based on MXene@Co/NC holds a broad linearity range from 0.01 μM to 45.0 μM with a low limit of detection (LOD) of 3.3 nM (S/N = 3, S means the detection signal, while N represents the noise of the instrument). Moreover, the proposed sensor displays excellent anti-interference ability, superior reproducibility, excellent stability, and successfully achieves actual applications for CBZ detection in a lettuce sample.

Efficient light-driven hydrogen evolution and azo dye degradation over the GdVO4@g-C3N4 heterostructure

A straightforward hydrothermal technique was used for the synthesis of a g-C₃N₄/GdVO₄ (CN/GdV) heterostructure as an alternate material for energy and environmental applications. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the synthesized g-C₃N₄ (CN), GdVO₄ (GdV), and the CN/GdV heterostructure. The characterization results revealed the distribution of GdV over CN sheets. The as-fabricated materials were tested for their capacity to evolve hydrogen gas and degrade two azo dyes (Amaranth; AMR and Reactive Red2; RR2) in the presence of visible light. When compared to pure CN and GdV, the efficiency of CN/GdV toward hydrogen evolution was high, with H₂ evolution of 8234, 10 838, and 16 234 μmol g^-1 in 4 h, respectively. The CN/GdV heterostructure was able to degrade 96% and 93% of AMR (60 min) and RR2 (80 min), respectively. The enhanced activity with CN/GdV could be attributed to the type-II heterostructure and decreased recombination of charge carriers. The intermediate analysis of AMR and RR2 degradation was conducted using mass spectrometry (MS). The mechanism of photocatalysis was investigated and is discussed based on the optical and electrochemical characterizations. The efficient photocatalytic characteristics of CN/GdV could promote further research on metal vanadate nanocomposite materials.

Enhanced laccase production by mutagenized Myrothecium verrucaria using corn stover as a carbon source and its potential in the degradation of 2-chlorophen

Chlorophenols are widely used in industry and are known environmental pollutants. The degradation of chlorophenols is important for environmental remediation. In this study, we evaluated the biodegradation of 2-chlorophenol using crude laccase produced by Myrothecium verrucaria. Atmospheric and room temperature plasma technology was used to increase laccase production. The culture conditions of the M-6 mutant were optimized. Our results showed that corn stover could replace glucose as a carbon source and promote laccase production. The maximum laccase activity of 30.08 U/mL was achieved after optimization, which was a 19.04-fold increase. The biodegradation rate of 2-chlorophenol using crude laccase was 97.13%, a positive correlation was determined between laccase activity and degradation rate. The toxicity of 2-CP was substantially reduced after degradation by laccase solution. Our findings show the feasibility of the use of corn stover in laccase production by M. verrucaria mutant and the subsequent biodegradation of 2-chlorophenol using crude laccase.