Critical reviews in analytical chemistry最新文献

Though metal ions like copper, iron, zinc, etc. are essential, but their dyshomeostasis is associated with several disorders. Therefore, fast, sensitive, and cost-effective monitoring of these cations will have a significant impact. Many recently reported small organic molecules were able to detect a specific metal ion because of certain variations in the electron/charge transfer processes occurring in those molecules after binding with metal ions. In this context, Schiff base molecules were widely used as fluorescence turn-on/turn-off probes for the detection of metal ions like Al³⁺, Cu²⁺, Zn²⁺, Fe³⁺, Ag⁺, heavy metal ions, etc. In this article, we have reviewed the recent developments in fluorimetric chemosensing of metal ions by Schiff bases based on the photo-induced electron transfer (PET) process. A variety of examples have been discussed in which PET was used as a cation recognition mechanism. Particular focus is placed on the molecular probes used for sensing, including their design, selectivity, sensitivity, and in some cases their potential bioimaging applications.

The physiological and officinal functions of phytosterols are of great significance, and recent dietary guidelines have underscored the significance of incorporating them into a balanced diet. Furthermore, it exhibits inhibitory effects on tumor growth, stimulates cellular immunity, possesses anti-inflammatory, antioxidant, and antidiabetic properties. To gain a more comprehensive understanding of the role of phytosterols in public health, it is crucial to establish simple, rapid, eco-conscious, efficient, and highly sensitive techniques for their extraction and determination across various matrices. This review presents a thorough overview of various techniques used for extracting and analyzing phytosterols in diverse plant-derived foods, encompassing a range of advanced technologies like solid-phase extraction, microextraction, supercritical fluid extraction, QuEChERS, alongside traditional approaches. The detection techniques include liquid chromatography-based methods, gas chromatography-based methods, supercritical fluid chromatography, and other methodologies. Additionally, we conduct a thorough examination and comparison of various techniques while proposing future prospects.

Quantitative analysis of peptides in biological fluids offers a high diagnostic and prognostic tool to reflect the pathophysiological condition of the patient. Recently, methods based on liquid chromatography coupled with mass spectrometry (LC-MS) for the quantitative determination of intact peptides have been replacing traditionally used ligand-binding assays, which suffer from cross-reactivity issues. The use of "top-down" analysis of peptides is rapidly increasing since it does not undergo incomplete or non-reproducible digestion like "bottom-up" approaches. However, the low abundance of peptides and their peculiar characteristics, as well as the complexity of biological fluids, make their quantification challenging. Herein, the analytical pitfalls that may be encountered during the development of an LC-MS method for the analysis of intact peptides in biological fluids are discussed. Challenges in the pre-analytical phase, stability after sampling and sample processing, significantly impact the accuracy of peptide quantification. Emerging techniques, such as microextractions, are becoming crucial for improved sample cleanup and enrichment of target analytes. A comparison between the roles of high-resolution and low-resolution mass spectrometry in the quantification of intact peptides, as well as the introduction of supercharging reagents to enhance ionization, will be discussed.

The compositions of natural products are diverse and complex, which makes accurate analysis a challenging task. Surface-enhanced Raman spectroscopy (SERS) provides a means for the analysis of natural products. This review thoroughly examines the applications of SERS in the field of natural products, ranging from component identification and quality control to the clarification of mechanisms of action. It emphasizes SERS' capability to identify active ingredients in complex mixtures and monitor production for quality assurance. SERS can also elucidate the mechanisms of action. Nevertheless, challenges such as substrate standardization and the complexity of data processing exist. Future development will focus on innovative design, automation, and integration. Through continuous innovation and interdisciplinary collaboration, SERS is expected to play a crucial role in natural product research and development, further promoting the growth of the natural product industry. This review aims to provide a comprehensive perspective and support for natural product quality control and new drug development.

An overview of the latest advances in the design of electrochemical sensor architectures dedicated to the determination of drugs from the statin class is presented in this review. Statins are drugs widely consumed for cholesterol control, and their determination in different matrices through the application of electroanalysis is growing considering advantages such as operational simplicity, lower cost and ease of sample preparation. Within the context of statins, electrochemical sensor architectures can be subdivided into conventional/classical electrodes such as glassy carbon electrodes, carbon paste electrodes, pencil graphite electrodes, boron-doped diamond electrodes and metallic electrodes, and more modern electrode systems, including the screen-printed electrodes and 3D-printed electrodes. Thus, different aspects related to the preparation of these electrochemical sensors and analytical performance are presented, also reflecting advances in terms of designs of new architectures and possible improvements not previously reviewed. Analyzed samples, advantages and disadvantages of different implemented sensor's modification strategies and perspectives for the electroanalysis of statins are also included throughout the work.

Aroma is one of the important indexes to evaluate food quality. The formation of food aroma is based on the interaction of complex substances. The accurate quantification of aroma substances in food has significance in the analysis of aroma substances in food. In this review, the basic principle and significance of stable isotope dilution analysis is introduced, general steps for flavor analysis and its historical progress in food flavor analysis is discussed. Additionally, the application progress of stable isotope dilution analysis in food flavor analysis from 2019 to 2023 has been described in detail, which is also categorized by food. Finally, the accuracy and superiority of stable isotope dilution analysis as an accurate quantitative analysis method were discussed.

Receptor-ligand binding, which is crucial to a variety of biomedical and biochemical processes, immune responses, and signal transduction, forms the basis for many biotechnological applications. The specific binding between a receptor and a ligand is the beginning of the biological function of the receptor or ligand molecule. Therefore, a summary study of methods for quantitative determination of receptor-ligand interaction kinetics is necessary. In this review, the kinetic parameters that traditionally describe the pattern of receptor-ligand interactions are first introduced. We then summarize and analyze methods for quantitative determination of receptor-ligand interaction kinetics, including direct kinetic measurements, cytology-based measurements, computational chemistry-based measurements, and single-molecule force spectrometry technique measurements of receptor-ligand interactions. Direct measurements of the kinetics of receptor-ligand interactions are further described in methods based on surface plasmon resonance, surface-enhanced Raman spectroscopy, photoelectrochemistry, mass spectrometry binding analyses, nuclear magnetic resonance technology, and electrochemical methods. This review provides a comprehensive and accurate description of the kinetic studies of protein receptor-ligand interactions.

Camellia oil is a high-value edible seed oil, recommended by the Food and Agriculture Organization (FAO). It is essential to develop accurate and rapid analytical methods to authenticate camellia oil due to its susceptibility to adulteration. Recently, hyphenated chromatography-mass spectrometry, especially high-resolution mass spectrometry using chemometrics, has become a promising platform for the identification of camellia oil. Based on the compositional analysis, the fatty acid, sterol, phenol, and tocopherol profiles (or fingerprints) were utilized as predictor variables for assessing authenticity. The review systematically summarizes the workflow of chromatography-mass spectrometry technologies and comprehensively investigates recent metabolomic applications combined with chemometrics for camellia oil authentication. Metabolomics has significantly improved our understanding of camellia oil composition at the molecular level, contributing to its identification and full characterization. Hence, its integration with standard analytical methods is essential to enhance the tools available for public and private laboratories to assess camellia oil authenticity. Integrating metabolomics with artificial intelligence is expected to accelerate drug discovery by identifying new metabolic pathways and biomarkers, promising to revolutionize medicine.

Total reflection X-ray fluorescence spectrometry (TXRF) is a pivotal technique in modern atomic spectroscopy, distinguished by its capability for multi-element simultaneous determination, a wide dynamic concentration range, samples do not require acid digestion. Additionally, TXRF exhibits negligible matrix effects when samples are prepared as thin films. Based on these unique features, recent research efforts have increasingly employed laboratory-built TXRF systems for the determination of major and trace elements in various samples. Given the diverse and intricate nature of TXRF systems components, this paper provides an overview of critical components that constitute these systems, compares the influence of various parameters on analytical performance, and offers recommendations for component selection. Additionally, recent applications of laboratory-built TXRF in fields such as environmental monitoring, nuclear energy, and food safety are discussed, with a focus on sample preparation, analyzed elements, and quantitative analysis are presented together with analytical parameters such as detection limits and recoveries. By introducing the instrument components and their practical applications, this paper aims to guide researchers in the construction and optimization of TXRF systems, thereby promoting the advancement of TXRF in future research and practical applications.

Aptamers, as short single-stranded nucleic acids, can bind to targets in a similar way to antibodies. Relying on the advantages of low cost, high stability, and flexibility, they are widely applied in biosensors, disease therapy, and synthetic biology. As an aptamer screening method, the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) offers almost unlimited possibilities for functional aptamer generation. However, at present, the SELEX procedure has not reached a satisfactory level, and it still faces some challenges in practical application, such as the relatively blind initial library, laborious and time-consuming selection process, typically requires 9-20 rounds for screening, and the entire process generally extends over 2-3 months, and sub-optimal performance of aptamers obtained. In the past few years, researchers have made great efforts to address these obstacles. Hence, in this review, we first summarize the aptamer screening mechanism and the existing limitations of SELEX. Then analyze the principle and technical key points of the SELEX optimization screening strategy. By incorporating rational library design, novel screening awareness, and advanced screening equipment, the number of aptamer screening cycles is significantly reduced to <8 rounds, with some methods achieving single-round screenings. This has led to a considerable decrease in the overall screening time to <3 weeks, while simultaneously enhancing the performance of the aptamers. Finally, critically discuss the present challenges and future directions of aptamer screening. This review aims to provide a practical reference for designing suitable aptamer screening methods.