Analytica Chimica Acta最新文献

{"title":"Advancements in multiresidue pesticide analysis in fruits and vegetables using micro-flow liquid chromatography coupled to tandem mass spectrometry","authors":"Florencia Jesús ,&nbsp;Víctor Cutillas ,&nbsp;Ana M. Aguilera del Real ,&nbsp;Amadeo Rodríguez Fernández-Alba","doi":"10.1016/j.aca.2025.344100","DOIUrl":"10.1016/j.aca.2025.344100","url":null,"abstract":"<div><h3>Background</h3><div>A reliable analysis of pesticide residues in fruits and vegetables is crucial for food safety and regulatory compliance. Traditionally, analytical-flow liquid chromatography coupled to mass spectrometry (LC-MS/MS) has been the gold standard but, shifting to low-flow LC-MS/MS presents an improved alternative that enhances sensitivity, reduces the injected amount of sample and aligns with the principles of green analytical chemistry. Operating at micro-flow rates significantly reduces solvent consumption and organic waste, which is particularly important for routine control laboratories. This approach maintains high sensitivity, robustness, and performance, addressing the critical need for greener, efficient, and reliable methodologies for multiresidue pesticide analysis.</div></div><div><h3>Results</h3><div>This study assessed the performance of a micro-flow LC system operating at a flow rate of 50 μL min⁻¹, coupled to a triple quadrupole mass spectrometer, for the multiresidue analysis of 257 pesticides in tomato and orange matrices, in compliance with the ISO 17025. The method showed excellent retention time stability, with deviations under 2.1 s across 50 injections. Peak area repeatability was robust, with relative standard deviations of 3.4 % for tomato and 2.9 % for orange. The instrumental limits of quantification demonstrated high sensitivity, with 89 % of pesticides identified at very low concentrations (0.001–0.002 mg kg⁻¹), outperforming the traditional analytical-flow LC-MS/MS method, which identified 75–81 % of compounds. Matrix effects were minimal, with less than 20 % signal suppression or enhancement for most compounds. The method was successfully tested through the analysis of proficiency tests samples, and the analysis of 39 real samples proved its applicability for routine food monitoring.</div></div><div><h3>Significance</h3><div>This work establishes micro-flow LC-MS/MS as an innovative method for multiresidue pesticide analysis in fruits and vegetables, combining high analytical performance with significant sustainability advantages, reducing solvent consumption by over fivefold compared to the conventional analytical-flow method. These benefits underscore micro-flow LC-MS/MS as a promising, efficient, and environmentally friendly option for multiresidue pesticide analysis, positioning it as a valuable tool for broader adoption in food safety analysis.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344100"},"PeriodicalIF":5.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced microextraction kinetics: Sorptive-dispersive vs. conventional techniques on rotating disks","authors":"Nicolás Morales ,&nbsp;Alejandra Molina-Balmaceda ,&nbsp;Daniel Arismendi ,&nbsp;Alberto Chisvert ,&nbsp;Pablo Richter","doi":"10.1016/j.aca.2025.344105","DOIUrl":"10.1016/j.aca.2025.344105","url":null,"abstract":"<div><h3>Background</h3><div>A new approach based on Stir Bar Sorptive Dispersive Microextraction (SBSDME), termed Rotating Disk Sorptive Dispersive Extraction (RDSDE), was developed to confirm and quantify the kinetic advantages of sorbent-based dispersive techniques compared to their non-dispersive counterparts. Among non-dispersive techniques, Rotating Disk Sorptive Extraction (RDSE) allows for a direct comparison with its dispersive counterpart, as the sorbent phase in RDSE can be confined within the disk cavity using the exact same amount as in the dispersive mode. This comparison is not feasible in stir bar sorptive extraction.</div></div><div><h3>Results</h3><div>The advantages of RDSE combined with the dispersion of magnetic sorbent materials were explored using RDSDE technology. Magnetic activated carbon (MAC) derived from avocado seeds was used as the sorbent, with triclosan (TCS), bisphenol A (BPA), ibuprofen (IBU), and 1-hydroxy-ibuprofen (1-OH-IBU) as representative analytes. The RDSDE method was optimized for efficiency and speed. Optimal conditions were: 10 mg of MAC, 20 min extraction at pH 2, acetone as desorption solvent and 10 min desorption. These parameters provided the best analytical response with minimal time and resource use. The method was then validated, and a kinetic comparison was performed. The results demonstrated that RDSDE reaches extraction equilibrium in approximately 20 min, significantly faster than RDSE. The initial extraction velocities were between 12 times higher for BPA and 43 times higher for IBU in the dispersive mode.</div></div><div><h3>Significance</h3><div>The kinetic comparison clearly shows that RDSDE is a more efficient extraction technique due to its rapid extraction equilibrium. The dispersive mechanism plays a crucial role in accelerating analyte extraction, as evidenced by the steeper extraction profiles of RDSDE compared to RDSE. Importantly, this study presents the first direct kinetic comparison between RDSDE and conventional RDSE, highlighting the novelty of the approach. This underscores the potential of RDSDE as a faster and more efficient method for extracting target compounds from aqueous samples, offering significant advantages in analytical performance and operational efficiency.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344105"},"PeriodicalIF":5.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Consolidating two laboratories into the most sustainable lab of the future: 2LabsToGo-Eco","authors":"Maria C.O. Romero, Kevin Jakob, Johannes Schmidt, Thomas Nimmerfroh, Wolfgang Schwack, Gertrud E. Morlock","doi":"10.1016/j.aca.2025.344103","DOIUrl":"https://doi.org/10.1016/j.aca.2025.344103","url":null,"abstract":"<h3>Background</h3>The miniaturized 2LabsToGo predecessor system consolidated most devices used in the planar chromatography laboratory and toxicological bioassay testing laboratory; however, important features for greater user convenience were still missing. It can be used for non-target chemical safety analysis of products on the global market or environmental samples to detect known and unknown hazardous compounds.<h3>Results</h3>The system had to be redeveloped due to the many changes and improvements and was termed 2LabsToGo-Eco to make this difference recognizable. Twelve new key elements were implemented for the first time, such as solar panels for power supply-free operation, autosampler for hands-free application of samples, Mini-Shaker, Nebulizer, and Mini-Incubator as smart bioassay tools, superior tools for imaging, and electronic mainboard to eliminate cable and circuit board clutter. It was again designed open-source for do-it-yourself assembly. Miniaturization and dematerialization let to the reduction (compared to the status quo) of instrument investment costs by a factor of 35, starting capital by a factor of 18, weight by a factor of 12, infrastructure and bench space requirement by a factor of 9, and power supply by a factor of 4 or even 711 using solar energy. The new 2LabsToGo-Eco was proven and demonstrated for quantitative non-target safety analysis of cosmetics, personal care products, and foods.<h3>Significance</h3>For the first time, the sustainable 2LabsToGo-Eco is ready to go viral to allow for a non-target safety analysis with a prioritization strategy using the consolidated chromatography–bioassay lab. It boosts the transformation of laboratories towards sustainability, enables mobile on-site testing, allows customization of instruments, and democratizes access to chromatography and bioassay equipment.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"65 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mathematical model-assisted HPLC-MS/MS analysis on global, pseudo-targeted ceramide profiling and quantitation in serum","authors":"Fei Ge ,&nbsp;Jingai Jian ,&nbsp;Na Li ,&nbsp;Jingzhi Yang ,&nbsp;Yufan Chao ,&nbsp;Xin Dong","doi":"10.1016/j.aca.2025.344099","DOIUrl":"10.1016/j.aca.2025.344099","url":null,"abstract":"<div><div>Ceramides (Cers) play a crucial role in sphingolipid metabolism with multiple biological activities and functions. Due to the high regularity and variability of their structures, there exist thousands of possible Cers. The structural diversity endows them with various biological functions but also poses significant challenges for qualitative and quantitative analysis. The lack of in-depth characterization methods for such lipids resulted in only a small fraction of Cers being reported, severely hindering the exploration of their biological functions and activities. This work presented a lipid analysis method based on a liquid chromatography-mass spectrometry platform, enabling the accurate quantification of 337 Cers simultaneously. Supported by a mathematical model, this work succeeded in generating a quadratic equation relationship between retention time and Cers carbon number. Subsequently, this method was applied to the large-scale quantitative detection of Cers in serum samples from Alzheimer's disease (AD) patients, identifying and characterizing 62 differential Cers. These could potentially serve as serum biomarkers for AD diagnosis. This study demonstrates a strategy for the large-scale in-depth characterization of complex endogenous lipid molecules with highly variable and regular structures in the absence of sufficient commercial standard materials. This work provides a novel analysis method and reference for exploring and developing the functions of such endogenous bioactive molecules.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344099"},"PeriodicalIF":5.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-interaction (substituted-phenylcarbamate)-hydroxypropyl-β-cyclodextrin chiral stationary phases for liquid chromatography","authors":"Junchao Zhu,&nbsp;Linna Xu,&nbsp;Wentao Xu,&nbsp;Huizhen Ni,&nbsp;Songlin Chen,&nbsp;Chu Chu,&nbsp;Dongping Cheng,&nbsp;Shengqiang Tong","doi":"10.1016/j.aca.2025.344104","DOIUrl":"10.1016/j.aca.2025.344104","url":null,"abstract":"<div><h3>Background</h3><div>(Substituted-phenylcarbamate)-<em>β</em>-cyclodextrin (<em>β</em>-CD) chiral stationary phases (CSPs) showed high enantioselectivity and complementary capabilities compared to polysaccharide-based CSPs in liquid chromatography. Most of the previous works were about preparation and application of (substituted-phenylcarbamate)-<em>β</em>-CD, while very limited works was available reporting modified hydroxypropyl-<em>β</em>-CD (HP-<em>β</em>-CD) used for CSP. As matter of fact, HP-<em>β</em>-CD was more frequently used than native <em>β</em>-CD as chiral selector in many chiral separation techniques. Therefore, it was great of significance to investigate preparation of multi-interaction (substituted-phenylcarbamate)-HP-<em>β</em>-CD CSPs and its application in chiral separation.</div></div><div><h3>Results</h3><div>Three new multi-interaction (substituted-phenylcarbamate)-HP-<em>β</em>-CD CSPs were prepared and investigated, including (3-chloro-4-methylphenylcarbamate)-HP-<em>β</em>-CD CSP, (4-chloro-3-methylphenylcarbamate)-HP-<em>β</em>-CD CSP and (5-chloro-2-methylphenylcarbamate)-HP-<em>β</em>-CD CSP. The structure and morphology of the three chiral selectors as well as their stationary phase were characterized by ¹H NMR spectra, elemental analysis, infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. Degree of substitution, stability, repeatability and reproducibility of the (substituted-phenylcarbamate)-HP-<em>β</em>-CD CSPs were investigated. A total of 56 racemic compounds were examined on the three (substituted-phenylcarbamate)-HP-<em>β</em>-CD CSPs using reversed-phase elution mode. It was found that enantioselective recognition capability of the three (substituted-phenylcarbamate)-HP-<em>β</em>-CD CSPs was greatly improved compared with that of traditional HP-<em>β</em>-CD CSPs, which was demonstrated by the number of successful enantioseparated racemates and increased enantioseparation efficiency. Applications of the three CSPs in high performance liquid chromatographic enantioseparations indicated that each of them showed different enantiorecognition ability toward different type of racemic structures, which showed high complementary enantiorecognition ability with traditional <em>β</em>-CD-based CSPs.</div></div><div><h3>Significance</h3><div>An efficient one-pot reaction strategy for synthesis of (substituted-phenylcarbamate)-HP-<em>β</em>-CD CSPs was developed. It was found that enantiorecognition and peak resolutions (<em>Rs</em>) were greatly improved compared with traditional HP-<em>β</em>-CD CSP and <em>β</em>-CD CSP. The improved chiral separation performance of multi-interaction HP-<em>β</em>-CD CSPs was demonstrated, providing valuable insights for the development of efficient chiral separation methods while expanding the potential applications of HP-<em>β</em>-CD in chiral liquid chromatography.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344104"},"PeriodicalIF":5.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructing BiOI@Nv/g-C3N4 with S-scheme heterojunction for enhanced photoelectrochemical performances towards highly sensitive and selective detection of trace chlorpyrifos","authors":"Xi Chen ,&nbsp;Haicai Huang ,&nbsp;Shipeng Huang ,&nbsp;Qingping Wu ,&nbsp;Jingqiu Liu ,&nbsp;Haoyu Duan ,&nbsp;Houyang Chen","doi":"10.1016/j.aca.2025.344102","DOIUrl":"10.1016/j.aca.2025.344102","url":null,"abstract":"<div><div>Chlorpyrifos, one of the organophosphorus pesticide commonly used in the environment, may bring about an irreversible harm such as lung cancer to human body. Photoelectrochemical (PEC) detection techniques based on g-C₃N₄ for sensing chlorpyrifos have attracted increasing attentions, but impeded by several inherent constraints such as a limit of active sites and carriers transfer. To conquer these challenges, a photoelectrochemical sensor of BiOI@N_v/g-C₃N₄ with a step scheme heterojunction was thereby proposed for the sensitive and selective detection of trace chlorpyrifos. Herein, the created N vacancies facilitated the migration of photo-electrons from BiOI to recombine with the holes of N_v/g-C₃N₄ under light irradiation. A powerful oriented built-in electric field was established directing from N_v/g-C₃N₄ to BiOI. The photocurrent intensity of the as-prepared sensor exhibited over 7.6 times higher than that of pure g-C₃N₄, showing a well PEC performance. High selectivity of the developed sensor was attributed to the specific interaction between Bi sites of the developed composites and the S, N atoms in chlorpyrifos. Such sensitive and steady PEC sensor exhibited a linear detection range from 0.01 to 20 ppb with a detection limit of 0.004 ppb. Further, the sensor displayed reliable performance when applied to real river water and soil samples, achieving nice recovery rates. Unlike traditional PEC sensor, this one was prepared into S-scheme heterojunction by creating a N defect-induced driving force based on the altered built-in electric field. The work not only provides experimental evidences but also advances the fundamental theories so as to offer a robust g–C₃N₄–based PEC platform for environmental analysis.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1359 ","pages":"Article 344102"},"PeriodicalIF":5.7,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exponential rolling circle amplification-hybridization chain reaction (EXRCA-HCR) for AgNPs@gel-enhanced fluorescence ultrasensitive detection of miRNA-21","authors":"Wenjiao Zhang ,&nbsp;Yuchen Song ,&nbsp;Dongmei Deng ,&nbsp;Meiyin Liu ,&nbsp;Huinan Chen ,&nbsp;Wanyi Zhang ,&nbsp;Hong Lei ,&nbsp;Zhiguo Li ,&nbsp;Liqiang Luo","doi":"10.1016/j.aca.2025.344095","DOIUrl":"10.1016/j.aca.2025.344095","url":null,"abstract":"<div><div>MicroRNA (miRNA) is a common tumor marker, whose abnormal expression is often closely related to the occurrence of various diseases. However, the conventional method for detecting miRNA is qRT-PCR, requiring additional reverse transcription steps, well-trained professionals, and expensive thermal cycling equipment. In this work, we propose a novel isothermal amplification technique (exponential rolling circle amplification-hybridization chain reaction, EXRCA-HCR) for AgNPs@gel-enhanced fluorescence specific and ultrasensitive detection of miRNA-21. This novel technique consists of rolling circle amplification (RCA), exponential isothermal amplification reaction (EXPAR) and hybridization chain reaction (HCR). Combining these three amplification methods, EXRCA-HCR provides a unique cascade amplification strategy, inheriting the advantages of linear amplification and exponential amplification. Under optimal conditions, this novel EXRCA-HCR exhibits a wide fluorescent detection range from 200 fM to 200 nM for miRNA-21, with low detection limit of 21.47 fM. By introducing AgNPs@gel, the fabricated paper-based fluorosensor based on EXRCA-HCR provides a simple and rapid visual detection of miRNA-21. This research puts forward a promising approach for detecting miRNA-21, which can be applied for early diagnosis.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344095"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SagMSI: A graph convolutional network framework for precise spatial segmentation in mass spectrometry imaging","authors":"Mudassir Shah ,&nbsp;Linlin Wang ,&nbsp;Lei Guo ,&nbsp;Chengyi Xie ,&nbsp;Thomas Ka-Yam Lam ,&nbsp;Lingli Deng ,&nbsp;Xiangnan Xu ,&nbsp;Jingjing Xu ,&nbsp;Jiyang Dong ,&nbsp;Zongwei Cai","doi":"10.1016/j.aca.2025.344098","DOIUrl":"10.1016/j.aca.2025.344098","url":null,"abstract":"<div><h3>Background</h3><div>Mass Spectrometry Imaging (MSI) is a label-free imaging technique used in spatial metabolomics to explore the distribution of various metabolites within biological tissues. Spatial segmentation plays a crucial role in the biochemical interpretation of MSI data, yet the inherent complexity of the data—characterized by large size, high dimensionality, and spectral nonlinearity—poses significant analytical challenges in MSI segmentation. Although deep learning approaches based on convolutional neural networks (CNNs) have shown considerable success in spatial segmentation for biomedical imaging, they often struggle to capture the comprehensive structural information of MSI data.</div></div><div><h3>Results</h3><div>We propose SagMSI, an unsupervised graph convolution network (GCN)-based segmentation strategy that combines spatial-aware graph construction of MSI data with a GCN module within a deep neural network. This approach enables flexible, effective, and precise spatial segmentation. We applied SagMSI to both simulated data and various MSI experimental datasets and compared its performance against three commonly used segmentation methods, including <em>t</em>-SNE + <em>k-</em>means, a pipeline implemented by the R package Cardinal, and a CNN-based segmentation method. Visual comparisons with histological images and quantitative evaluations using the silhouette coefficient and adjusted rand index demonstrate that SagMSI excels in segmenting complex tissues, revealing detailed sub-structures, and delineating distinct boundaries of sub-organs with minimal noise interference. The integration of graph-based neural networks with spatially structural information offers deeper insights into spatial omics.</div></div><div><h3>Significance</h3><div>The MSI data is modelled by graph structure so as to incorporate the biomolecular profiling and spatial adjacency within neighboring pixels. The GCN framework generates meaningful pixel representations by learning local and global contextual information through the graph-based structure, thus enabling precise segmentation of MSI. The approach demonstrated high flexibility, robustness to noise, and applicability in exploring complex tissue structures and identifying marker ions associated with microregions.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344098"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ion mobility spectrometer with heated sample inlet - Solution to the issue of temperature effect on resolving power","authors":"Martin Lippmann,&nbsp;Moritz Hitzemann,&nbsp;Timo Sawatzki,&nbsp;Jonas Winkelholz,&nbsp;Alexander Nitschke,&nbsp;Tim Kobelt,&nbsp;Stefan Zimmermann","doi":"10.1016/j.aca.2025.344097","DOIUrl":"10.1016/j.aca.2025.344097","url":null,"abstract":"<div><h3>Background</h3><div>One major challenge in detecting less volatile compounds with an ion mobility spectrometer (IMS) is preventing condensation of target molecules in the sampling line and ionization region to allow for fast response and recovery. Heating the entire device including the sampling line can of course mitigate condensation of such compounds, but this comes at the cost of reduced resolving power and compromised detection limits. Furthermore, a considerable amount of additional power and an IMS design with temperature-resistant components are needed.</div></div><div><h3>Results</h3><div>In this work, a different approach has been investigated, with a heated sample inlet in combination with a directed sample gas flow through the ionization region, but with the drift region at lower temperature. While this approach effectively addresses the issue of condensation, it results in an inhomogeneous temperature distribution within the drift region. Simulations and experimental data reveal that this uneven temperature distribution can significantly distort the peaks in the ion mobility spectrum, depending on the IMS orientation. However, positioning the IMS vertically, with the detector facing down, significantly minimizes temperature-induced peak distortion, thereby maintaining high resolving power. In this orientation, the IMS used in this work shows a resolving power of 80, while the IMS sample inlet and outlet are heated to 423 K. In addition, a directed sample gas flow in the ionization region is used to further reduce condensation in the ionization region.</div></div><div><h3>Significance and novelty</h3><div>The approach and findings revealed in this work allow the construction of IMS with a heated sample inlet to prevent condensation of less volatile compounds while also maintaining the high resolving power of a drift tube at room temperature. The results on the influence of the orientation of the IMS can also be applied to even higher temperatures.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344097"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Porous platinum nanozyme-amplified capacitance immunoassay for alpha-fetoprotein with hepatocellular carcinoma on an interdigitated gold micro-comb array","authors":"Huaxi Ma ,&nbsp;Dongqing Zhang ,&nbsp;Ting Lin ,&nbsp;Shenglong Lin,&nbsp;Wenjun Wu,&nbsp;Ziyuan Liao,&nbsp;Xiangmei Wang,&nbsp;Haibing Gao","doi":"10.1016/j.aca.2025.344101","DOIUrl":"10.1016/j.aca.2025.344101","url":null,"abstract":"<div><h3>Background</h3><div>Hepatocellular carcinoma, one of the most common malignancies, is the worldwide three cause leading the mortality of cancers. Alpha-fetoprotein (AFP) is a typical tumor marker for the recurrences of HCC, and can be utilized potentially during routine follow-up after HCC resection. Therefore, sensitive and accuracy detection of AFP is very critical at the early stage of hepatocellular carcinoma.</div></div><div><h3>Results</h3><div>In this work, an <em>in-situ</em> amplified capacitance immunoassay was designed for highly sensitive determination of AFP in biological fluids. The capacitance immunosensor was fabricated by means of immobilizing <em>anti</em>-AFP capture antibodies on an interdigitated gold micro-comb array through a carbodiimide coupling method. Porous platinum nanoparticles (PtNPs) were used for the labeling of <em>anti</em>-AFP detection antibody. The presence of target analyte induced the formation of the sandwiched immunocomplex between capture antibody and detection antibody. The carried porous PtNPs with peroxidase-like activity catalyzed 4-chloro-1-naphethol oxidation to produce an insoluble benzo-4-chlorohexadienone precipitation in the presence of hydrogen peroxide. The precipitation was coated on the micro-comb electrode, thus causing the capacitance change. Two labeling protocols including porous PtNPs and solid PtNPs were investigated for determination of AFP, and improved analytical features were acquired with porous PtNPs. Under optimal conditions, porous PtNP-based capacitance immunoassay gave a good linear response from 0.01 ng mL⁻¹ to 300 ng mL⁻¹ AFP with a detection limit of 7.4 pg mL⁻¹. Good reproducibility, high specificity and long-term stability were also achieved. In addition, 15 human serum specimens were determined through our method, and the results were in accordance with those obtained from commercial AFP enzyme-linked immunosorbent assay.</div></div><div><h3>Significance</h3><div>This capacitance immunoassay offers promise for sensitive and cost-effective detection of cancer biomarkers without the requirement of natural enzymes. Importantly, porous PtNP-based labeling strategy opens a new horizon for advanced development of capacitance immunoassays.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1358 ","pages":"Article 344101"},"PeriodicalIF":5.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}