Manganese oxide anchored on carbon modified halloysite nanotubes: An electrochemical platform for the determination of chloramphenicol

Employing Pd nanoparticles decorated on halloysite nanotube/carbon composite for electrochemical aptasensing of HER2 in breast cancer patients

An effective biosensing platform is described based on halloysite nanotube/carbon composite decorated with Pd nanoparticles (HNT/C@Pd NPs). A novel electrochemical aptasensor was designed using the proposed nano-platform to determine human epidermal growth factor receptor 2 (HER2), a breast cancer biomarker. Inherently, aptasensing interfaces provide high sensitivity and selectivity for tumor markers owing to the high specific surface area of HNT/C and good conductivity stems from deposition of Pd NPs into HNT/C composite. With a correlation coefficient of 0.996, the electrochemical aptasensor demonstrated a wide linear range from 0.03 ng/mL to 9 ng/mL. The limit of detection (LOD) of the established assay was 8 pg/mL based on S/N = 3 method. Further, the designed biosensor demonstrated acceptable selectivity, good reproducibility, and high stability. The applicability of the impedimetric sensor in human serum samples was also examined and compared to enzyme-linked immunosorbent assay (ELISA) assay (p-value >0.05). Based on the results, it was found that the proposed methodology can be used in quantification of breast cancer markers for early diagnosis and treatment.

Few Layer Ti3C2 MXene-Based Label-Free Aptasensor for Ultrasensitive Determination of Chloramphenicol in Milk

Quantitative detection of veterinary drug residues in animal-derived food is of great significance. In this work, a simple and label-free electrochemical aptasensor for the highly sensitive detection of chloramphenicol (CAP) in milk was successfully developed based on a new biosensing method, where the single- or few-layer Ti3C2 MXene nanosheets functionalized via the specific aptamer by self-assembly were used as electrode modifiers for a glassy carbon electrode (aptamer/Ti3C2 MXene/GCE). Differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy (SEM), atomic force microscope (AFM), and so on were utilized for electrochemical and morphological characterization. Under the optimized conditions, the constructed aptasensor exhibited excellent performance with a wider linearity to CAP in the range from 10 fM to 1 μM and a low detection limit of 1 fM. Aptamer/Ti3C2 MXene/GCE demonstrated remarkable selectivity over other potentially interfering antibiotics, as well as exceptional reproducibility and stability. In addition, the aptasensor was successfully applied to determine CAP in milk with acceptable recovery values of 96.13% to 108.15% and relative standard deviations below 9%. Therefore, the proposed electrochemical aptasensor is an excellent alternative for determining CAP in food samples.

A review on nanomaterial-based electrodes for the electrochemical detection of chloramphenicol and furazolidone antibiotics

To grow food for people, antibiotics were used, and these antibiotics can accumulate in the human body through food metabolism, which may have remarkably harmful effects on human health and safety. Therefore, low-cost sensors are needed for the detection of antibiotic residues in food samples. Recently, nanomaterial-based electrochemical sensors such as carbon nanoparticles, graphene nanoparticles, metal oxide nanoparticles, metal nanoparticles, and metal-organic nanostructures have been successfully used as sensing materials for the detection of chloramphenicol (CP) and furazolidone (FZ) antibiotics. However, additional efforts are still needed to fabricate effective multi-functional nanomaterial-based electrodes for the preparation of portable electrochemical sensor devices. The current review focuses on a quick introduction to CP and FZ antibiotics, followed by an outline of the current electrochemical analytical methods. In addition, we have discussed in-depth different nanoparticle supports for the electrochemical detection of CP and FZ in different matrices such as food, environmental, and biological samples. Finally, a summary of the current problems and future perspectives in this area are also highlighted.

Unraveling the hazardous impact of diverse contaminants in the marine environment: Detection and remedial approach through nanomaterials and nano-biosensors

Marine pollution is one of the most underlooked forms of pollution as it affects most aquatic lives and public health in the coastal area. The diverse form of the hazardous pollutant in the marine ecosystem leads the serious genetic level disorders and diseases which include cancer, diabetes, arthritis, reproductive, and neurological diseases such as Parkinson's, Alzheimer's, and several microbial infections. Therefore, a recent alarming study on these pollutants, the microplastics have been voiced out in many countries worldwide, it was even found to be in the human placenta. In recent times, nanomaterials have demonstrated their potential in the detection and remediation of sensitive contaminants. In this review, we presented a comprehensive overview of the source, and distribution of diverse marine pollution on both aquatic and human health by summarizing the concentration of diverse pollutions (heavy metals, pesticides, microbial toxins, and micro/nano plastics) in marine samples such as soil, water, and seafood. Followed by emphasizing its ecotoxicological impact on aquatic animal life and coastal public health. Also discussed are the applicability and advancements of nanomaterials and nano-based biosensors in the detection, prevention, and remediation of diverse pollution in the marine ecosystem.

Advances of Drugs Electroanalysis Based on Direct Electrochemical Redox on Electrodes: A Review

The strong development of mankind is inseparable from the proper use of drugs, and the electroanalytical research of drugs occupies an important position in the field of analytical chemistry. This review mainly elaborates the research progress of drugs electroanalysis based on direct electrochemical redox on various electrodes for the recent decade from 2011 to 2021. At first, we summarize some frequently used electrochemical data processing and electrochemical mechanism research derivation methods in the literature. Then, according to the drug therapeutic and application/usage purposes, the research progress of drugs electrochemical analysis is classified and discussed, where we focus on drugs electrochemical reaction mechanism. At the same time, the comparisons of electrochemical sensing performance of the drugs on various electrodes from recent studies are listed, so that readers can more intuitively compare and understand the electroanalytical sensing performance of each modified electrode for each of the drug. Finally, this review discusses the shortcomings and prospects of the drugs electroanalysis based on direct electrochemical redox research.

Past and Present of Electrochemical Sensors and Methods for Amphenicol Antibiotic Analysis

Amphenicols are broad-spectrum antibiotics. Despite their benefits, they also present toxic effects and therefore their presence in animal-derived food was regulated. Various analytical methods have been reported for their trace analysis in food and environmental samples, as well as in the quality control of pharmaceuticals. Among these methods, the electrochemical ones are simpler, more rapid and cost-effective. The working electrode is the core of any electroanalytical method because the selectivity and sensitivity of the determination depend on its surface activity. Therefore, this review offers a comprehensive overview of the electrochemical sensors and methods along with their performance characteristics for chloramphenicol, thiamphenicol and florfenicol detection, with a focus on those reported in the last five years. Electrode modification procedures and analytical applications of the recently described devices for amphenicol electroanalysis in various matrices (pharmaceuticals, environmental, foods), together with the sample preparation methods were discussed. Therefore, the information and the concepts contained in this review can be a starting point for future new findings in the field of amphenicol electrochemical detection.

Laser-enabled flexible electrochemical sensor on finger for fast food security detection

Today's rampant abuse of antibiotics and lean meat powder disturbs environment and threatens public human health. Therefore, fast in-site detection of antibiotics or lean meat powder residue could avoid potential risks. In this work, flexible graphene electrodes (FGE) were easily and facilely patterned and prepared by CO₂ laser at room environment, which was coupled with a portable electrochemical analyzer for electronic signal transmission. Laser-enabled flexible electrochemical sensor on finger can be used for rapid real-time in-site electrochemical identification of chloramphenicol (CAP), clenbuterol (CLB) and ractopamine (RAC) in meat. The electrochemical response of CAP, CLB and RAC is investigated with the limit of detection of 2.70, 1.29 and 7.81 μM and the linear range of 10-200, 5-80 and 25-250 μM in phosphate buffer saline (PBS) pH 7.0, correspondingly. The minimum detection concentrations of CAP, CLB and RAC were 20, 10 and 30 μM, respectively, in actual samples of pork. And the minimum detection concentrations of CAP, CLB and RAC were 10, 5 and 25 μM in milk, respectively. Such an integrated sensing platform enriches application of sensors on finger in food security and provides information that prevents drug containments from entering food chain.

Development of an electrochemical sensor based on a cobalt oxide/tin oxide composite for determination of antibiotic drug ornidazole

A schematic illustration of the electrochemical performance towards sensing of ODZ at the Co₃O₄/SnO₂/GCE.