Talanta最新文献

The development of a novel multifunctional adsorbent for the sensitive detection and capture of antibiotic residues in environmental and food samples presents a significant challenge. In this study, we synthesized a pioneering nanocomposite, ILs@PC, by encapsulating task-specific ionic liquids (ILs) within nitrogen-doped porous carbon (PC) derived from metal-triazolate frameworks. This ILs@PC nanocomposite functions as a multifunctional adsorbent in dispersive solid-phase extraction (DSPE), enabling simultaneous sorptive removal, sensitive detection, and molecular sieve selection. The ILs@PC demonstrated enhanced adsorption efficiency and sensitivity for sulfonamide antibiotics (SAs) compared to the pristine PC, attributed to the nanoconfinement effect of the ILs and the influence of pore volume on this effect. When integrated with high-performance liquid chromatography (HPLC), the ILs@PC-based DSPE method achieved a detection limit of 0.75-1.88 μg L^-1 for SAs, along with satisfactory recoveries of 86.0 %-111.9 %. Additionally, a portable syringe device was developed to facilitate rapid on-site extraction and enrichment of SAs. The practicality of this method was validated through its successful application in detecting SAs in real samples, including lake water and milk. This approach highlights its potential for efficient and rapid monitoring of antibiotic residues in both environmental and food systems.

Drug-induced liver injury (DILI) is a crucial factor that poses a significant threat to human health. DILI process leads to the changes of reactive oxygen species and reactive nitrogen species content in cells, which leads to oxidative and nitrosative stress in cells. However, the high reactivity of hypochlorous acid (HOCl) and peroxynitrite (ONOO⁻), combined with a lack of in situ imaging techniques, has hindered a detailed understanding of their roles in DILI. Therefore, this paper reports a novel sequence-activatable dual-locked molecular probe HA-P3 for the identification and imaging of two DILI-related biomarkers. First, HA-P3 selectively reacts with reactive oxygen species HOCl to leave the recognition receptor diethyl thiocarbamate to form HA-P2. Subsequently, HA-P2 reacts with ONOO⁻, liberating the fluorophore 4-hydroxy-1,8-naphthalimide, which emits a strong fluorescence signal. The two-step reaction effectively reduces the probability of false positive in predicting DILI. HA-P3 achieved the sensitive detection of HOCl and ONOO^- in different cells and zebrafish. Furthermore, HA-P3 can distinguish between normal liver cells and hepatoma cells and monitored the elevated levels of HOCl and ONOO⁻ during acetaminophen (APAP)-induced cellular damage. It is worth noting that in the APAP-induced mouse model, the positive correlation between HOCl and ONOO^- and DILI was revealed, providing strong direct evidence for the relationship between oxidative/nitrosative stress and DILI.

A total of 57 European, Canadian and North American postage stamps, all in red shades, were analyzed with the main goal of unraveling which pigments or dyes were used to produce the red color in the period dated from 1841 to 1899. Both non-destructive techniques, including X-Ray Fluorescence (XRF), Fiber Optics Reflectance Spectra (FORS), and Steady State Fluorescence Spectroscopy, and destructive methods such as High-Performance Liquid Chromatography coupled with Diode-Array Detection (HPLC-DAD) and Electrospray Ionization High-Resolution Mass Spectrometry (ESI-HRMS), were utilized for a comprehensive analysis. The examined red shades were identified as originating from either a single pigment or dye, or a combination of both. XRF analysis detected red lead/litharge in 14 postage stamps, vermilion in 8 and iron oxide in 4. The mapping results obtained by this technique were shown to be very important in the determination of inorganic pigments. Most specimens contained a natural organic dye, with carminic acid being the most prevalent, appearing in 30 samples. In contrast, alizarin was identified in only 3 of the examined postage stamps. A synthetic dye, eosin Y, first synthesised by Heinrich Caro in 1871, was detected in 11 stamps and suggested by FORS and steady-state fluorescence in 6 others printed from 1879 onwards. HPLC-HRMS provided more detailed information on the natural colorant. In 19 samples both organic and inorganic dyes or pigments were found to coexist. It has been shown that spectroscopic techniques, when used with an appropriate database, can play a role in suggesting the presence of certain compounds that are subsequently detected by other techniques.

The dried matrix spot (DMS) method, initially developed for neonatal blood screening, has gained prevalence in various research fields for its efficiency in handling small sample volumes and its adaptability to diverse analytical techniques. This study presents the results of the first systematic investigation of direct multi-element analysis in DMS of human blood and plasma samples with Particle Induced X-ray Emission (PIXE). Internal standard addition was used to address the issue of DMS heterogeneity and to eliminate the need for determining the sample volume equivalent, allowing a single-spot (single-punch) measurement. The method was tested for linearity, accuracy, precision and limit of detection (LOD) using reference materials. It was applied to samples from healthy volunteers and compared to analysis results obtained by ICP-OES showing good agreement. Sample volumes as low as 50 μL were sufficient for the quantification of Na, Mg, P, S, K, Ca, Fe, and Zn in whole blood, and Na, Mg, P, S, K, and Ca in plasma samples without significant matrix effects being observed. Chlorine, which is also an electrolyte element present in high enough concentrations for determination by PIXE, was not addressed in this study due to a lack of reference materials. The results highlight PIXE as a viable alternative to other techniques that are sensitive to matrix issues, require larger sample volumes and/or sample treatment. Overall, this work establishes DMS sampling as being suitable for direct multi-element analysis of biological samples by PIXE, offering detection limits at the mg/L level which is sufficient for determination of electrolyte and essential trace elements and paving the way for its broader application in clinical and research settings.

The growing modern industry has promoted the development of gas sensors for environmental monitoring and safety checks. However, the traditional chemical resistance gas sensor still has some disadvantages such as high power consumption and limited detection, mainly due to the lack of charge transfer ability of sensing materials. In this paper, an ordered UV-activated gas sensor with mesoporous ZnO/TiO₂ nanotube composite was prepared by precisely controlling the growth of ZnO on the inner wall of TiO₂ nanotube. Based on the synergistic effect of Knudsen diffusion, photoactivation, and in situ heterojunction amplification, the charge transfer performance under room temperature of ZnO/TiO₂ nanotube composites is improved. Compared to TiO₂ nanotube sensor, the ZnO/TiO₂ sensor has a 10-fold enhanced response to NO₂, and the detection limit is as low as 50 ppb. Moreover, we studied the performance of ZnO/TiO₂ sensor on NO₂ in campus, street entrance and chemical plant, and comparing with commercial sensor, found that the detection error and detection limit of our sensor is lower, which proves the sensor has great application prospect in practical detection. This work provides a successful method for in-situ construction of ordered mesoporous materials and gives a solution for the design of advanced photoelectric gas sensors.

This study reports the development and implementation of a straightforward, rapid, and cost-effective voltammetric technique for piroxicam (PIR) detection at nanomolar concentrations in biological and environmental samples. The method involved the use of a screen-printed electrode (SPE) enhanced with a combination of Printex L6 carbon (PL6C) and polyaniline-based activated carbon (PAC) on a chitosan film crosslinked with epichlorohydrin (CTS:EPH). The detection was carried out using square-wave adsorptive anodic stripping voltammetry (SWAdASV) in a 0.10 mol L^-1 phosphate buffer solution at pH 6.0. The approach employed yielded a low limit of detection of 4.5 × 10^-9 mol L^-1 and a linear range of 5.0 × 10^-8 to 8.8 × 10^-6 mol L^-1 (r = 0.999). The PAC-PL6C-CTS:EPH/SPE sensor was effectively employed for PIR detection in synthetic urine and river water samples, where its reliability was proven through addition and recovery tests. The results obtained from the application of the proposed voltammetric method closely matched those recorded under high-performance liquid chromatography (HPLC), which was used as a reference method. The findings show that the technique proposed in this study offers a simple, quick, and highly effective alternative mechanism for PIR detection in both biological and environmental matrices.

The individualized administration and pharmacokinetics profiling are integral to the safe use of antibody drugs in immunotherapy. Here, we propose an electrochemical platform for the highly sensitive and selective detection of antibody drugs, taking advantage of the affinity capture by the peptide mimotopes together with the signal amplification by the biologically-driven RAFT polymerization (BDRP). Briefly, the BDRP-based platform involves the capture of antibody drugs by peptide mimotopes, the labeling of multiple reversible addition-fragmentation chain-transfer (RAFT) agents to the glycan chains of antibody drugs, and the BDRP-enabled controlled recruitment of numerous redox labels. The BDRP-based signal amplification relies on the reduction of RAFT agents by NADH coenzymes into the carbon-centered radicals, which can propagate efficiently into long polymer chains by reacting with the ferrocene-derivated monomers, recruiting numerous redox labels to the glycan chains of antibody drugs. The BDRP is conducted at the physiological temperature (i.e., 37 °C) and in the absence of external stimuli or radical sources, holding the advantages of biological compatibility and desirable simplicity over conventional RAFT polymerization approaches. The developed platform is highly selective and the detection limit in the presence of rituximab as the target was determined to be 0.14 ng/mL. Moreover, the applicability of the BDRP-based platform in the sensitive assay of antibody drugs in serum samples has been validated. In view of the biocompatibility, desirable simplicity, and cost-effectiveness, the BDRP-based platform shows great promise in the quantitative assay of antibody drugs.

A manganese porphyrin wrapped DNA dendrimer (Mn-DD) was developed through enzyme-free DNA self-assembly and simple and mild groove binding of porphyrin. The Mn-DD not only possessed plenty of manganese porphyrin to amplify the chemiluminescence (CL) signal, but also can be modified with diverse groups via DNA hybridization. Combined with an immunosensor array, Mn-DD can be utilized for CL immunoassay of multiple mycotoxins as a universal tag. Under optimal conditions, Mn-DD-based CL imaging immunoassay of aflatoxin B₁ (AFB₁), ochratoxin A (OTA), and zearalenone (ZEN) exhibited broad linear ranges over 4 orders of magnitude and detection limits as low as 0.87, 0.75, and 0.79 pg mL^-1, respectively. It was also utilized in the examination of real coix seed samples, yielding reliable results. High sensitivity, as well as simple operation, low reagent dosage, acceptable accuracy and stability showed the tag and the approach broad application prospects in quality control of food and medicine.

The rapid advancement of the Internet of Things has created a substantial demand for portable gas sensors. Nevertheless, the development of gas sensors that can fulfill the demanding criteria of high sensitivity and rapid response time continues to pose a considerable challenge. Herein, an in-situ anchoring strategy is proposed to construct CNTs@MOF heterostructure to establish strong electronic coupling and charge relocation for enhancing the monitoring capabilities of isopropanol (freshness markers for fruits) at room temperature. The in-situ anchoring process prevents Zn-MOF (ZIF-8) self-aggregation, ensuring efficient transport channels for target analytes and enhancing active site utilization. Moreover, the synergistic effect of each component in the composite is optimized. Consequently, the gas sensor based on the CNTs@ZIF-8 heterostructure achieved an ultrahigh isopropanol response of 57.87 (40 ppm, R_a/R_g) at room temperature and 60% relative humidity, exhibiting rapid response kinetics (38 s, 30 ppm) and durability. This study offers a fresh perspective on the structural design of oxygen-inert CNTs materials.

Array sensing employs cross-identification among analytes and various sensing units to identify substances or complex systems. This manuscript presents a fluorescence ratio sensing array based on lectin responses for the accurate identification of different bacteria. This strategy uses a saccharide-sensitive polymer as the sensing unit within the sensor. By incorporating various saccharides, it regulates the properties of the single sensing unit at the molecular level, altering its interaction with the analyte. This modulation leads to the generation of multiple distinct detection signals for the target, effectively facilitating the goal of array sensing. This approach streamlines the design and construction of the array sensor, while simultaneously enhancing detection efficiency. Not only does this sensing strategy achieve the differentiation and quantification of various types of lectins, but it also enables the identification of different bacterial species based on their unique lectin response profiles. This research introduces a novel approach that simplifies the construction of array sensors and simultaneously furnishes a potent tool for diagnosing and assessing bacterial infections within clinical settings.