Analytical Methods最新文献

A Förster resonance energy transfer (FRET)-based fluorescent probe (NCA) was developed for highly sensitive and selective detection of hydrogen sulfide (H₂S). In this design, coumarin (CA) serves as the fluorescent donor and nitrobenzoxadiazole (NB) acts as an energy acceptor and reactive site. Upon exposure to H₂S, cleavage of the NB unit interrupts the FRET process and restores CA fluorescence, producing a 16-fold signal enhancement at 463 nm with a detection limit of 0.11 µM. Under optimized conditions (Britton–Robinson (BR) buffer, pH 8, 15 min), NCA enables rapid and selective detection of H₂S over competing biological species. Practical applications were demonstrated by integrating NCA into a smartphone-assisted test strip platform, which achieved recoveries of 98.7–109.9% in tap and lake water. Furthermore, NCA successfully imaged both endogenous and exogenous H₂S in human lung carcinoma (A549) cells with low cytotoxicity. These results highlight the potential of NCA as a versatile tool for environmental monitoring and biological studies of H₂S.

Fipronil is a broad-spectrum insecticide that is widely applied in agriculture, household, and public health applications. However, its abuse can lead to environmental pollution and endanger human health. Therefore, it is important to develop a simple and low-cost method for detecting fipronil. In this study, a novel fluorescence sensor for the detection of fipronil in the environment was prepared by combining molecular imprinting technology (MIT) with a metal–organic framework (MOF) surface modified upconversion micro-particle (UCMP) composite. The results showed that the fluorescence intensity of UCMPs@UiO-66-(COOH)₂@MIP decreased linearly as the fipronil concentration increased in the range of 0.1–0.8 mg mL⁻¹. Under the optimal conditions, the imprinting factor reached 3.01, and the limit of detection (LOD) was 0.058 mg mL⁻¹. This method exhibits good specificity and quantitative detection capability for fipronil over a wide concentration range. At the spiked concentration levels of 0.2, 0.4, 0.6, and 0.8 mg mL⁻¹, the recovery range of fipronil in water reached 82.04–90.73% with a relative standard deviation (RSD) of 2.47–5.18%, which indicates the potential of this molecularly imprinted fluorescent sensor for environmental detection.

Iodinated X-ray contrast media (ICM) have emerged as persistent contaminants due to their high polarity, persistence and biological inertness. In this work, a sampling method for monitoring the time-integrated concentrations of six ICMs, iohexol, iopamidol, iomeprol, iopromide, iodixanol and ioversol, in sewage effluents has been developed, using diffusive gradients in the thin-films (DGT) technique based on a graphene nanosheet gel as the binding layer and commercial polyethersulfone membrane as the diffusion layer (G-DGT). The uptakes of the G-DGT for the six ICMs were evaluated in synthetic solutions and found to be independent of pH in the range of 4–9, ionic strength ranging from 1 × 10⁻⁴ to 0.1 mol L⁻¹, and dissolved fulvic acid and tannic acid ranging from 0 to 20 mg L⁻¹. Three spiked freshwater samples showed good precision and good agreement between C_DGT and C_SOLN, confirming that G-DGT is capable of accurately determining the six ICMs in freshwater samples. The time-integrated concentrations of ioversol and iopamidol can be determined with better reproducibility with respective to the grab sampling technique, enabling accurate monitoring of outflows from a clinical practice. These results illustrate that G-DGT is an effective sampling tool for obtaining time-integrated concentrations of ICMs in complex sewage effluent.

This study employed a combined analytical approach utilizing EDXRF, XRD, FTIR, and thermal dilatometry (TD) to comprehensively analyze the raw material characteristics, provenance, mineral composition, and firing temperatures of Shang dynasty grey pottery excavated from the Shuyuanjie (SYJ) site. Based on significant differences in the SiO₂, K₂O, and CaO content, the grey pottery bodies can be classified into three distinct raw material types. The chemical compositions of pottery from the SYJ and Xiaoshuangqiao (XSQ) sites are highly similar, suggesting a possible common raw material source. The principal phases within the grey pottery bodies are quartz and microcline, with some samples containing trace amounts of cristobalite and rutile. XRD and FTIR analyses confirmed that this batch of grey pottery underwent high-temperature firing, with firing temperatures all exceeding 750 °C. Thermal dilatometry analysis (using a single heating cycle combined with the first derivative curve) determined that the firing temperatures of the grey pottery range between 870 °C and 990 °C; all samples are underfired bodies. For pottery of unknown firing histories, water absorption and apparent porosity cannot serve as reliable proxies for determining the high or low firing temperature of the body.

Creatinine is a compound naturally produced by the body through biochemical processes involving the metabolism of creatine phosphate in the muscles. It serves as an important biomarker for assessing kidney function, while also acting as a strong indicator of thyroid dysfunction and muscle injury. Therefore, the development of analytical methods aimed at rapid and efficient determination of creatinine is extremely important to assist in the diagnosis of these dysfunctional changes in the body, especially in relation to renal failure. In this context, the present study describes a fast, inexpensive, sensitive and highly reliable analytical methodology for the direct determination of creatinine in hemodialysis wastewater, artificial urine (simulating human urine) and bovine serum albumin (simulating human blood) samples. The method employs an electrochemical sensor based on a glassy carbon electrode (GCE) modified with copper nanoparticles (GCE-CuNPs). The GCE-CuNPs sensor was developed through amperometric modification of the GCE surface with CuNPs, followed by electroactivation via cyclic voltammetry in a 0.1 mol L⁻¹ NaOH medium. Optimization studies identified the following parameters for optimal sensor performance: an electrodeposition time of 120 s, in an unstirred solution of CuSO₄ 6.0 mmol L⁻¹ (precursor solution), an electrodeposition potential of −0.20 V and amperometric detection potential of 0.70 V. The developed electrochemical sensor exhibited a linear response for creatinine determination in the concentration range of 0.025 to 1.0 mmol L⁻¹ with I_ap (µA) = 0.029 [creatinine] (mmol L⁻¹) + 1.92 × 10⁻⁷ (R² = 0.9964), limit of detection (LOD) of 19.0 µmol L⁻¹, limit of quantification (LOQ) of 58.0 µmol L⁻¹ and sensitivity of 0.029 µA mmol⁻¹ L. Additionally, the GCE-CuNPs sensor showed good repeatability, selectivity and average recoveries around 102.5% (n = 5). Finally, the GCE-CuNPs sensor was successfully applied for the determination of creatinine in hemodialysis wastewater, bovine serum albumin and artificial urine samples, demonstrating its practical utility.

During the metabolic process of benzene and its derivatives in living organisms, a series of metabolic products are produced. These metabolites have significant application value in environmental monitoring, occupational health and disease diagnosis. The detection of specific metabolites of benzene series substances can accurately reflect the true level of exposure. In this study, a method based on UPLC-MS/MS was developed for the determination of eight benzene biometabolites in urine. The target substances in urine samples were extracted using HLB columns, separated by gradient elution with HSS T3 liquid chromatography columns, and detected by tandem mass spectrometry. The results showed good linearity in the linear range with correlation coefficients greater than 0.999 for all eight substances. The recoveries were all in the range of 80–120%, and the detection limits were lower than 0.011 ng mL⁻¹. The method is simple to operate, the accuracy and precision meet the detection requirements, and it can be applied to the detection of real samples.

Cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) share similar functional groups, such as thiol (–SH) and amino (–NH₂), but differ in their spatial structures. These structural differences can lead to distinct binding behaviors with fluorescent probes that possess multiple reactive sites, resulting in diverse reaction products and thereby producing distinct color and fluorescence responses. Based on this principle, a phenyl selenide-substituted coumarin probe (PSeC) capable of distinguishing GSH from Cys and Hcy is designed and synthesized in this work. The probe itself is non-fluorescent, but exhibits strong fluorescence upon reacting with biothiols. Within the PSeC structure, both the phenyl selenide and aldehyde groups serve as potential reaction sites for biothiol interaction, yielding characteristic fluorescence emissions—green for Cys and Hcy, and red for GSH. The probe displayed fluorescence enhancement factors of 90-fold for GSH, 142-fold for Hcy, and 29-fold for Cys. Moreover, the response time toward Cys was markedly longer than those toward Hcy and GSH, enabling discrimination of the three biothiols through distinct fluorescence channels and kinetic behaviors. Furthermore, the probe demonstrated the capability to differentiate Hcy and GSH in living cells based on their unique fluorescence signatures.

Antibiotic resistance genes (ARGs) are emerging pollutants that pose significant threats to both the environment and human health. Rapid detection of ARGs is essential for monitoring their levels and controlling their spread. However, traditional detection methods are often time-consuming and require specialized equipment, leading to delays. To address this issue, this study developed a novel method for visual microarray detection of ARGs, including sul1, tetA, qepA, macB, and vanR. This method employs ARG-specific dual probes combined with silver staining signal cascade amplification technology. A centrifuge-free concentration device has been developed that can directly enrich nucleic acid fragments from environmental samples, with traditional nucleic acid extraction and PCR amplification being eliminated. Using a dual probe combined with silver staining enhancement dual probe amplification technology, rapid high-throughput detection of low-concentration ARG is achieved. No specialized equipment is required, and on-site visual detection of ARG was realized. The detection method can detect target genes (sul1, tetA, qepA, macB, and vanR) within a concentration range of 0.411 µg mL⁻¹ to 55.9 µg mL⁻¹, with the lowest detectable target gene concentration being 0.411 µg mL⁻¹. This study marks the first integration of a centrifuge-free concentration device, specific dual probes, and silver staining signal cascade amplification technology to establish a rapid visual detection method for ARGs using a microarray. The developed detection method holds significant potential not only for the detection and monitoring of ARGs but also as a prototype for devising future detection strategies.

Microfluidic devices have proven to be a valuable innovation in medical and biological research, offering a fast and efficient platform for testing. Among the materials used for constructing microfluidic channels, off-stoichiometry thiol–ene (OSTE) polymers are especially promising due to their ease of fabrication and lower small-molecule absorption compared to the current gold-standard material, polydimethylsiloxane (PDMS). However, some studies have indicated that there are challenges with binding molecules to the surface thiol groups as they are easily oxidized in air. In this study, a novel linker was synthesized and evaluated for its performance at binding proteins to the surface of OSTE polymer, using a custom-built spectroscopic measurement system. In addition, the results obtained were compared to regular enzyme-linked immunosorbent assay (ELISA) plates and performance of the linker in functionalized microfluidic chips was investigated. Our results indicate that the synthesized linker binds proteins to the OSTE surface and can offer a similar performance to ELISA plates in protein concentration tests highlighting its potential for use in microfluidic chip functionalization.

Advances in proteomics are reshaping our understanding of cancer biology by enabling the direct quantification of proteins and their modifications in complex biological systems. Among emerging mass spectrometry techniques, Data-Independent Acquisition (DIA) has established itself as a transformative approach for cancer proteomics. DIA offers unprecedented depth, reproducibility, and scalability by systematically fragmenting all precursor ions across defined mass ranges, allowing comprehensive proteome coverage and retrospective data analysis. This review highlights the fundamental principles of DIA-MS, recent technological developments—including spectral library-free workflows, and their impact on cancer research. We discuss the application of DIA in tumor classification, biomarker discovery, therapeutic target identification, and treatment response monitoring. Particular attention is given to its compatibility with clinical samples such as formalin-fixed paraffin-embedded (FFPE) tissues and its integration into large-scale efforts like CPTAC. Current challenges with the technique will be explored, including data analysis complexity and standardization, and future directions that could bring DIA-MS closer to clinical utility. DIA-MS is rapidly evolving into a cornerstone technology for precision oncology, with the potential to bridge research and clinical practice through robust, high-resolution proteomic profiling.