Analytical biochemistry最新文献

Desorption ionisation on silicon mass spectrometry (DIOS-MS) allows for the detection of low molecular weight species from fluid samples. However, this method remains scarcely used for clinical diagnosis likely because of a lack of knowledge about the desorption/ionization mechanism as well as about the interplay between the surface and analyte properties which are effective in desorption/ionization, impeding the optimization of the DIOS-MS analysis. Herein, the normalized intensity of the DIOS-MS peaks at [M+H]⁺ of seven amino acids on four different porous silicon modified surfaces are investigated. These amino acids (arginine, phenylalanine, methionine, glutamine, leucine, cysteine and valine) have different isoelectric points, proton affinities, and octanol-water partition coefficients. The four selected surfaces were oxidized porous silicon (SiO₂), the same porous silicon modified with a propyl dimethyl ethoxy silane, octadecyl dimethyl ethoxy silane or 3 amino propyl dimethyl ethoxy silane (CH₃-short, CH₃-long and NH₃⁺, respectively). These surfaces present different electrical charges, alkyl chain lengths, and hydrophilic/hydrophobic properties. For each surface, the intensities of the protonated molecules ([M+H]⁺) are discussed with respect to the electrical charge and proton affinity of the amino acids, their z-distributions inside the pores (determined by time of flight secondary ion mass spectrometry profiling), their surface interaction energies (calculated by molecular dynamics simulations), the interfacial water content and the proton availability for each surface.

In this work we presented how the use of suitable electroanalytical, thermodynamic and spectroscopic methods combined with proper experimental conditions can provide comprehensive information on the interaction between metal ions and peptides in solution, as a successful strategy for studying biological systems. Our candidate peptide is calcitermin, an effective metal chelator with significant anti-Candida and antibacterial activity in the presence of divalent metals. While the bioinorganic chemistry of calcitermin with zinc and copper is quite well described in the literature, no data about nickel complexes are available; we therefore deepened calcitermin ability to form nickel complexes by different analytical techniques, including potentiometry, ultraviolet-visible absorption spectrophotometry, circular dichroism and high-resolution mass spectrometry. Moreover, for the first time we have investigated the antiviral activity of calcitermin and its metal complexes towards Herpes simplex type 1. Despite the nickel-associated slow kinetics, which requires specific experimental precautions, calcitermin forms stable complexes with this cation at different pH conditions. Both the apopeptide and its metal complexes show a random coil secondary structure, which is often characteristic of viral cellular adhesion inhibition. This research highlights that calcitermin and its metal complexes can interfere with viral infections, particularly HSV-1, most likely by altering cell membrane permeability.

This study developed a microwave-aided spectrofluorimetric method for in-vivo characterizing teneligliptin-loaded solid dispersion adsorbate (TNG-SDA) using a quality by design approach. The microwave-aided chemical reaction was applied for derivatization of non-fluorescent teneligliptin with NBD-Cl (7-chloro-4-nitrobenzoxadiazole). TNG-SDA was prepared to enhance the solubility and bioavailability of teneligliptin, a BCS (Biopharmaceutical Classification System) class II drug. The method utilized environmentally friendly solvents and employed analytical quality by design principles for optimization. Critical method parameters were identified through failure mode impact analysis and optimized using response surface modelling. The fluorescence spectra of teneligliptin exhibited linearity across the concentration range of 50-250 ng/mL, with a correlation coefficient of 0.9978. The developed method was found to be accurate, precise, robust, specific and sensitive for estimation of teneligliptin. The method was applied to evaluate in vitro dissolution, pharmacokinetics, and pharmacodynamic of TNG-SDA compared to commercial formulations. Results showed significant improvements in teneligliptin solubility and bioavailability with the developed SDA. The microwave-aided derivatized fluorescent product was characterized by mass spectrometry. The method demonstrated environmental sustainability, robustness, sensitivity, cost-effectiveness, and user-friendliness when evaluated using white analytical chemistry approaches. It provided a sensitive and green alternative to existing hyphenated techniques for nanogram-level teneligliptin detection in pharmacokinetic studies.

Flow injection analysis coupled with electrochemical detection (FIA-ECD) techniques has to be a key technological development for wide variety of applications in various domains such as synthetic analytical chemistry, materials science, biomedical and point-of-care devices. FIA-ECD techniques have to be unique due to decreasing the time of analysis, sample pre-treatment, reactions and separation-free detection for multi-analytes. In biomedical domain, various electrochemical sensors were decorated with bioactive molecules, i.e., DNA, antibodies, enzymes along with biocompatible polymers for the detection of biologically important chemicals and analytes. The flexibility and practical applicability of these sensors may serve as a new pattern for clinical and biomedical analytical instrumentations. This review covers the highlights and overview of the most successful and promising electrochemical sensors, biosensors and immunosensors integrated with the flow injection analysis platforms, fabrication and analytical parameters, pros and cons of these sensor technologies, challenges and future opportunities in point-of-care clinical analysis.

Gazeous hydrogen peroxide (H₂O₂) is commonly used for disinfection of room surfaces or sterilization of medical devices. Disinfection and sterilization processes are controlled by mean values measured at sterilizer chamber or room level. However, the surface phenomena (adsorption/ condensation) taking place on inoculum are essential and still not well-known. In the present study, a solution of water and H₂O₂ is sprayed in a room disinfection system (Glosair 400, ASP) for 12min. Condensation mass, H₂O₂ concentration, relative humidity (RH), macro zoom observations and inactivation kinetics of various microorganisms (Staphyloccocus aureus, Pseudomonas aeruginosa Candida albicans, Aspergillus niger) are reported. Macro-zoom observations reveal condensation and bubbling activities. Microbial inactivation is found optimal at low initial RH, corresponding to high H₂O₂ vapor concentration and low condensed mass. H₂O₂ concentration in the condensate is high and probably boosted by fractional condensation. In surface disinfection processes, inactivation of microorganisms occurs in presence of condensation although excessive condensation, due to high initial RH conditions or the presence of salt, decreases the microbial inactivation efficiency by dilution. While the present experimental conditions differ from those prevailing in H₂O₂ sterilization (59 % H₂O₂ under vacuum) or industrial disinfection processes (30% H₂O₂ at atmospheric pressure), they are partially transposable.

Flavonoids represent an important research topic in the analytical chemistry of secondary plant metabolites. During habitual laboratory determinations, preliminary quantitative analysis is often associated with in vitro colorimetric assessment. Total flavonoid content (TFC) is used as screening method with high relevance in the chemical analysis of plants and derived products, being typically applied before HPLC-MS phytochemical profiling. Its importance stems from affordability, simplicity, rapidity and low cost. The AlCl₃ assay, with or without NaNO₂ addition, is the most used method in the present, although less frequently used methods (using 2,4-dinitrophenylhydrazine, dimethylamino-cinnamaldehyde, or diethylene glycol) show potential for complementary and specific determinations. Given the prevalence of research papers focusing on a single method for "total flavonoid" determination, we identified the need for an objective and critical comparison of existing methodologies. Moreover, a special notice is dedicated to the past and the future of in vitro TFC determinations, in the context of recent advances in flavonoid research. The focal point of this review is to serve as a basis for laboratory protocol reorganization regarding TFC determination, as a powerful tool before mass spectrometry, as well as to present a potential complementary analysis protocol applicable to biological samples. Among the methods found in the literature, SBC was the only assay providing accurate determinations of TFC.

Brucellosis, a significant zoonotic disease, poses a threat to both livestock and human health. Infections in livestock lead to abortion, infertility, and substantial economic losses in the industry. In humans, acute brucellosis can progress to a chronic condition, resulting in multisystemic infections with high morbidity and mortality rates. Additionally, the bioterrorism potential of certain Brucella species through aerosol transmission poses risks to laboratory workers and livestock handlers. Therefore, there is an urgent need for rapid and precise diagnosis of brucellosis in both animals and humans. Even with the availability of routine diagnostic techniques that are effective they frequently have some limitations. Biosensors, as innovative techniques, have demonstrated significant potential in detecting various pathogens with high efficiency. These biosensors can identify specific analytes, biomolecules of pathogenic bacteria, secreted antibodies against bacteria, and even the bacterial body in real time. Their high sensitivity, selectivity, and user-friendly configurations make them valuable tools for diagnostics. In this comprehensive review, beside the reviewing routine diagnostic tests for detecting brucellosis and discussing the positive and negative aspects of these methods, we explore different types of biosensors and their applications in diagnosing brucellosis. We hope to show how these advancements can result in quicker and more precise disease detection by offering a thorough evaluation of these technologies performance and contrasting it with more conventional diagnostic techniques. This improves patient outcomes by lowering the complications linked to delayed diagnosis in addition to advancing scientific knowledge of brucellosis.

Aptamers, discovered in the 1990s, have marked a significant milestone in the fields of therapeutics and diagnostics. This review provides a comprehensive survey of aptamers, focusing on their diagnostic applications. It especially encapsulates a decade of aptamer, encompassing research, patents, and market trends. The unique properties and inherent stability of aptamers are discussed, highlighting their potential for various clinical applications. It goes on to introduce biosensor design, emphasizing the advantages of aptamers over antibodies as conventional molecular recognition interface. The operation and design of aptasensors are examined, with a focus on single- and dual-site binding configurations and their respective recognition modes. Paper-based sensors are highlighted as cost-effective, user-friendly alternatives that are gaining widespread adoption, particularly in point-of-care platforms.

In order to achieve high quality production of vitamin E and plant sterols, it is necessary to conduct rapid and accurate detection of fungal toxins in their production raw material (vegetable oil deodorizer distillate, VODD). In this study, the flower-like biomimetic enzyme of silver-doped ZnO was synthesized through wet chemical method and in-situ reduction method. Based on above work, a flower-like biomimetic enzyme modified glass carbon electrode was fabricated, and its excellent detection capability against fungal toxins zearalenone was confirmed through electrochemical analysis. The detection limit was 8 ng mL^-1, with a linear range of 40 ng mL^-1-25 μg mL^-1. Simultaneously, the biomimetic enzyme sensor takes only 10 minutes from preparation to completion of detection, and the RSD between the 7 repeated test results was only 0.612 %. After seven days of storage, the current response value remains 91.5 % of the initial value. In practical applications, the recovery rate of zearalenone in VODD using this sensor ranged from 98.1% to 102.08 %, yielding satisfactory results. Therefore, the novel flower-like biomimetic enzyme represents an ideal choice for developing zearalenone sensors and holds promising prospects for wide application in fungal toxins analysis.

This work represents different spectrophotometric techniques for concurrent quantification of Indacaterol (IND) and Mometasone furoate (MOM); co-formulated inhalation capsules to control asthma symptoms. Direct spectrophotometric (D⁰) approach was applied for IND assay. While, absorption factor (AF), ratio difference (RD), mean centering of the ratio spectra (MC), and continuous wavelet transform (CW) techniques were utilized for MOM quantification. The applied methods' validation was accomplished relative to the ICH guidelines. Within the linearity range of (4-20 μg/mL), these approaches provided accurate and precise assessment of IND and MOM in laboratory-synthetic mixtures and pharmaceutical formulation with determination coefficients higher than 0.9997. Moreover, the proposed methods demonstrated good detection and quantification levels. The respective LOD and LOQ for IND were (0.33 μg/mL) and (1.01 μg/mL). While, the LOD and LOQ for MOM were ranging from (0.16-0.30 μg/mL) and (0.47-0.91 μg/mL), respectively. Statistical comparison revealed no significant differences between the findings derived from the proposed methods and the reported one. The applied methods' environmental effect was cheeked using Analytical Greenness Calculator (AGREE), Blue Applicability Grade Index (BAGI), and Red-Green-Blue 12 (RGB12). All the utilized metrics showed reliable scores, approving that the proposed methods were adhered to the sustainability principles.