Analytica Chimica Acta最新文献

{"title":"Flexible metal-organic frameworks with dual-state emitters (DSEs) Photoluminescence for portable detection and information encryption","authors":"Qiao Han ,&nbsp;Qingbo An ,&nbsp;Xiao Li ,&nbsp;Jiaxing Chang ,&nbsp;Si Liu ,&nbsp;Yining Wang ,&nbsp;Zhong-min Su","doi":"10.1016/j.aca.2025.344684","DOIUrl":"10.1016/j.aca.2025.344684","url":null,"abstract":"<div><h3>Background</h3><div>Developing convenient, rapid fluorescent sensors for antibiotic detection is imperative for public health.</div></div><div><h3>Results</h3><div>In this article, four new metal-organic frameworks with dual-state emitters (DSEs) have been synthesized named as CUST-670∼673. CUST-670∼673 exhibit good structural stability and luminescence, serving as fluorescence sensors for tetracycline antibiotics with fluorescence color from blue to yellow-green. Portable visual detection cotton swabs and writable MOFs membranes were developed for rapid, easy detection of tetracyclines in real foods (e.g., milk, beef) and simple information encryption. The recovery rate of this method (98.1–100.3 %) is comparable to that of HPLC, with a relative standard deviation (RSD) below 1.42 %.</div></div><div><h3>Significance</h3><div>This work highlights MOFs' promising applications in food detection and information encryption, providing an experimental basis for subsequent practical use.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344684"},"PeriodicalIF":6.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084351","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":"Spectrometer-free plasmonic biosensor for rapid detection of egg allergen ovomucoid","authors":"Daiki Hirabayashi,&nbsp;Hiromu Miki,&nbsp;Mana Toma","doi":"10.1016/j.aca.2025.344660","DOIUrl":"10.1016/j.aca.2025.344660","url":null,"abstract":"<div><h3>Background</h3><div>Food allergies are immune-mediated disorders triggered by specific food proteins, with symptoms ranging from mild to severe. Prevalence is increasing globally, particularly in children, prompting regulatory measures such as allergen labeling. However, accidental exposure remains a concern, especially in processed foods. Although biosensors offer promising on-site detection capabilities, their range remains limited. Ovomucoid (OVM), the dominant and highly antigenic egg allergen, is underrepresented in biosensing studies despite its clinical significance, highlighting the need for targeted development.</div></div><div><h3>Results</h3><div>We developed a spectrometer-free, colorimetric plasmonic biosensor for the direct detection of ovomucoid (OVM), the primary allergen in egg allergy. The sensor employs silver nanodome arrays that exhibit plasmonic color shifts upon target binding, quantified by changes in color space coordinates. A direct immunoassay enabled the detection of OVM within a concentration range of several to several tens of μg/mL, which corresponds to levels known to induce allergic reactions. The detection limit was determined to be 0.024 μg/mL. High selectivity for OVM was confirmed, with no significant response to non-target proteins. Additionally, the sensor produced clear signals from egg white powder, demonstrating its applicability to real food samples. Finally, a proof-of-concept demonstration of OVM detection in a food matrix was achieved.</div></div><div><h3>Significance</h3><div>This study introduces a compact, spectrometer-free plasmonic biosensor integrating metasurfaces, antifouling chemistry, and simple imaging for sensitive, label-free detection of food allergens. Its scalability, ease of use, and compatibility with smartphone-based analysis highlight its potential for on-site applications and pave the way for self-used food allergen testing.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344660"},"PeriodicalIF":6.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084296","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":"Integrating cyclodextrin fluorescence sensing array and machine learning for rapid screening and detection of perfluoroalkyl substances","authors":"Jiancheng Zha ,&nbsp;Feng Liu ,&nbsp;Muyuan Ma ,&nbsp;Yuan Zhou ,&nbsp;Yue Shen ,&nbsp;Lei Sun ,&nbsp;Jing Su ,&nbsp;Chong Hu ,&nbsp;Shuai Wang ,&nbsp;Panpan Cui","doi":"10.1016/j.aca.2025.344680","DOIUrl":"10.1016/j.aca.2025.344680","url":null,"abstract":"<div><h3>Background</h3><div>Perfluoroalkyl substances (PFASs) are persistent environmental toxins posing significant health risks, with drinking water being a major exposure route. Current gold-standard detection via liquid chromatography-mass spectrometry (LC-MS) is hindered by high cost, complexity, and lack of portability, limiting rapid on-site screening. While fluorescence sensors offer alternatives, existing designs lack multiplex detection capability or require intricate fabrication. To address this gap, we developed a supramolecular fluorescence sensor array exploiting host-guest chemistry between β-cyclodextrin polymer (β-CDP) and dye probes, integrated with machine learning for rapid multi-PFAS screening in water.</div></div><div><h3>Results</h3><div>A 4 x 6 sensor array was constructed using β-cyclodextrin polymer (β-CDP) complexes with four dyes (NPN, AFR, CC, PR). Differential competitive binding of six PFASs generated unique fluorescence response patterns. These PFASs included perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), perfluoroheptanoic acid (PFHpA), and perfluorohexanoic acid (PFHxA). Linear discriminant analysis (LDA) enabled simultaneous discrimination and quantification of all six PFASs within 10 min, achieving detection limits of 38 ng/L (PFOA) and 31 ng/L (PFOS). The array accurately classified PFAS mixtures (binary to quaternary) at μg/L levels. A modular deep learning platform quantified PFASs in real water samples with only 0.66 % relative error versus LC-MS. Validation using surface water spiked with 5 μg/L PFOA confirmed high accuracy (predicted: 5.2345 μg/L; LC-MS: 5.2692 μg/L).</div></div><div><h3>Significance</h3><div>This work establishes the host-guest fluorescence array coupled with machine learning for multiplex PFASs detection, overcoming limitations of single-analyte sensors and lab-bound instruments. The method provides a portable, cost-effective platform for on-site screening with LC-MS-level accuracy, addressing urgent needs for environmental monitoring. Its modular design allows seamless integration into field-deployable devices, offering transformative potential for rapid water quality assessment and regulatory compliance.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344680"},"PeriodicalIF":6.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078025","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":"Thermostable CNTs@Au NPs nanocomposites for high-temperature assisted SERS molecular fingerprinting of two natural folates","authors":"Zhou Yang ,&nbsp;Lingling Dai ,&nbsp;Fangfei Liu ,&nbsp;Kun Jia ,&nbsp;Zhiyuan Ren ,&nbsp;Yanmei Yang ,&nbsp;Qingmeng Zhang ,&nbsp;Weifeng Li ,&nbsp;Ming Chen","doi":"10.1016/j.aca.2025.344678","DOIUrl":"10.1016/j.aca.2025.344678","url":null,"abstract":"<div><h3>Background</h3><div>Folate is an essential nutrient, but its bioavailability varies greatly depending on the molecular form present in food. The intake of forms that are not readily absorbed by the human body may lead to insufficient folate levels, particularly during pregnancy, thereby increasing the risk of birth defects. As a result, it is essential to develop a highly sensitive and accurate method capable of distinguishing between the two most common natural folates, 5-methyltetrahydrofolate (5-MTHF) and 5-formyltetrahydrofolate (5-FTHF), to ensure proper folate intake and health outcomes.</div></div><div><h3>Results</h3><div>In this study, a photochemical method was employed to load gold nanoparticles (Au NPs) onto carbon nanotubes (CNTs), successfully synthesizing CNTs@Au NPs nanocomposites that exhibit excellent thermal stability and robust surface-enhanced Raman scattering (SERS) activity. These nanocomposites, capable of maintaining structural integrity at temperatures as high as 400 °C, serve as highly effective substrates for <em>in situ</em> high-temperature SERS detection. Using this reliable high-temperature-assisted SERS approach, the structural changes of both folates at elevated temperatures were effectively monitored, enabling clear molecular fingerprinting and distinct differentiation between the two natural folates. Moreover, the CNTs@Au NPs demonstrate exceptional sensitivity, achieving a detection limit as low as 10⁻⁸ M for both 5-MTHF and 5-FTHF, enabling accurate quantification of mixed folate samples and demonstrating reliable performance in real sample analysis.</div></div><div><h3>Significance</h3><div>The CNTs@Au NPs with <em>in situ</em> high-temperature SERS capabilities show great potential for various analytical applications. In particular, they provide an effective method for monitoring the quality of folate in dietary supplements and fortified foods, thus contributing significantly to the safety and quality assurance of folate products in the market.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1378 ","pages":"Article 344678"},"PeriodicalIF":6.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078068","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":"A copper-bridged fluorescent sensor for sequential detection of Cu2+ and TKX-50: Synthesis, mechanism, and applications","authors":"Junli Shi ,&nbsp;Yongzheng Liu ,&nbsp;Yuqi Wu ,&nbsp;Yuxin Miao ,&nbsp;Xianping Xin ,&nbsp;Fanfan Shen ,&nbsp;Linxiu Zhao ,&nbsp;Duanlin Cao ,&nbsp;Shengling Li","doi":"10.1016/j.aca.2025.344683","DOIUrl":"10.1016/j.aca.2025.344683","url":null,"abstract":"<div><h3>Background</h3><div>5,5′-bistetrazole-1,1′-diolate (TKX-50), known as a novel explosive, is characterized by its high energy and low sensibility. It is a preferred explosive for criminals to carry out illegal attacks, posing a significant security risk. Therefore, the development of an efficient and highly specific detection method for TKX-50 is of significant practical importance. Fluorescent chemical sensors have demonstrated tremendous potential in explosive detection due to their high sensitivity, rapid response, and visual detection capabilities.</div></div><div><h3>Results</h3><div>A novel fluorescent chemical sensor <em>N’-((E)-5-((E)-2-(3-(dicyanomethylene)-5,5-dimethylcyclohex-1-en-</em>1-yl<em>)vinyl)-2-hydroxybenzylidene)-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide</em> (<strong>EXF</strong>) was designed and synthesized, and its structure was characterized by ¹H NMR, ¹³C NMR, and HRMS. The sensor can achieve continuous and specific detection of Cu²⁺ and TKX-50 through the ‘on-off-on’ fluorescence response. The <strong>EXF</strong> achieved a detection limit of 0.0968 μM for Cu²⁺. The complex [<strong>EXF</strong>-Cu²⁺] could specifically identify the novel explosive TKX-50 among a variety of explosives tested, with a detection limit of 0.0648 μM. In this study, the qualitative detection of Cu²⁺ and TKX-50 was carried out using test strips, and the quantitative determination of Cu²⁺ and TKX-50 in real water samples was successfully achieved based on the standard curve of a smartphone. Additionally, <strong>EXF</strong> can be used for the visualization of latent fingerprints (LFPs), demonstrating its potential application in the field of criminal investigations. The application of <strong>EXF</strong> for Cu²⁺ and TKX-50 imaging in living cells is also demonstrated.</div></div><div><h3>Significance</h3><div>The fluorescent sensor <strong>EXF</strong> establishes a connection between explosive detection and ion sensing by utilizing Cu²⁺ as a “bridge”. This research not only provides innovative explosive detection technologies, but also offers valuable design principles for multifunctional fluorescent sensors. The test strips and smartphone platform have preliminarily achieved on-site rapid qualitative and quantitative detection. And the LFPs imaging and detection in living cells further expand the application field, which has significant practical application value.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344683"},"PeriodicalIF":6.0,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084374","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":"A novel cucurbit[8]uril-based fluorescent probe for the detection of phenethylamine in urine","authors":"Min Chen ,&nbsp;Wen Min ,&nbsp;Shang-Wei Yuan ,&nbsp;Carl Redshaw ,&nbsp;Li-Xia Chen ,&nbsp;Qiu-Yu Peng ,&nbsp;Tao Yang ,&nbsp;Zhu Tao ,&nbsp;Xin Xiao","doi":"10.1016/j.aca.2025.344679","DOIUrl":"10.1016/j.aca.2025.344679","url":null,"abstract":"<div><h3>Background</h3><div>Beta-phenylethylamine (PEA), is known to scientists as the “mood hormone”, posing a threat to human health. In this study, an “on-off-on” supramolecular fluorescent probe was developed for the detection of PEA. The probe, namely PDT@2Q[8], was assembled from cucurbit[8]uril (Q[8]) and a coumarin derivative (PDT) via a host-guest interaction in a 2:1 binding ratio.</div></div><div><h3>Results</h3><div>The solution fluorescence was turned on again when PEA was added to PDT@2Q[8] in aqueous solution. The intensity of the fluorescence of the solution returned to blue following quenching, and the intensity of the fluorescence of the solution correlated with the concentration of PEA at 395 nm in a linear manner. The probes detection limit for PEA was 3.08 μM over the linear range 0.5–3 × 10⁻⁴ M. The probe was used for the detection of PEA in urine, and the detection limit for PEA was 1.34 μM over the linear range of 0.4–1.6 × 10⁻⁴ M.</div></div><div><h3>Significance</h3><div>As an “on-off-on” fluorescence-opening cucurbit[<em>n</em>]urils-based fluorescent probe, PDT@2Q[8] is not only simple to prepare, and of low-cost, but also exhibits significant fluorescence before and after the addition of PEA, with a fast response time and high sensitivity. This study provides a new fluorescent probe method for the detection of Beta-phenylethylamine (PEA).</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344679"},"PeriodicalIF":6.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078072","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":"A highly sensitive magnetic separation-assisted electrochemical sensor for detection of m6A-microRNA-17–5p based on rolling circle amplification and N3-kethoxal labeling strategy at LIG electrodes","authors":"Xi Cheng ,&nbsp;Jingyi Guo ,&nbsp;Huiyan Cao ,&nbsp;Haiyue Bi ,&nbsp;Shouquan Dong ,&nbsp;Hongling Wang ,&nbsp;Xiaocheng Weng ,&nbsp;Fang Wang","doi":"10.1016/j.aca.2025.344655","DOIUrl":"10.1016/j.aca.2025.344655","url":null,"abstract":"<div><h3>Background</h3><div>N6-methyladenosine (m6A) is a prevalent epigenetic modification in eukaryotic RNA and exerts critical regulatory effects on the progression of cancers and other human disorders. Recent studies have revealed a close association between methylation levels in microRNA (miRNA) and human cancers, emphasizing the diagnostic potential of m6A-modified miRNAs for gastrointestinal (GI) cancers. However, the low abundance of m6A in miRNAs has hindered further research, highlighting the need for highly sensitive and selective detection methods capable of analyzing m6A in complex biological samples.</div></div><div><h3>Results</h3><div>We developed an innovative biosensor based on a dual amplification strategy—combining rolling circle amplification (RCA) with N₃-kethoxal nucleic acid labeling—to enable ultrasensitive detection of m6A-microRNA-17–5p (m6A-RNA) at laser-induced graphene (LIG) electrodes. In the proposed strategy, m6A-RNA is quickly captured from the sample matrix using immunomagnetic beads and binds to the RCA primer–template complex. RCA is initiated under mild isothermal conditions, yielding long guanine-rich single-stranded DNAs (ssDNAs) that can be labeled with N₃-kethoxal. Subsequently, a copper-free click reaction between N₃-kethoxal and DBCO-biotin generates numerous binding sites for streptavidin-labeled horseradish peroxidase (SA-HRP), thereby catalyzing the electrochemical reaction system. The developed sensor demonstrated excellent sensitivity in the linear range of 0.1 pM–10 nM with a low detection limit of 10.1 fM, and performed well in selectivity, stability and reproducibility.</div></div><div><h3>Significance</h3><div>This study established a novel electrochemical signal amplification strategy, advancing the development of m6A modification analysis. Furthermore, the magnetic separation-assisted LIG electrode platform enables efficient target isolation from complex matrices while promoting device miniaturization. Successful detection of total RNA from MIA PaCa-2 cells and colorectal cancer (CRC) tissues demonstrates the method's applicability in clinical diagnostics, offering new avenues for GI cancer research and point-of-care biomarker testing.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344655"},"PeriodicalIF":6.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078070","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":"Sum of Euclidean Distance Differences and Sum of Absolute Manhattan Distance Differences: multicriteria decision making tools for small data tables","authors":"Károly Héberger","doi":"10.1016/j.aca.2025.344649","DOIUrl":"https://doi.org/10.1016/j.aca.2025.344649","url":null,"abstract":"<h3>Background</h3>Despite its advantages, rank transformation leads inevitably to information loss. This work presents an extension for sum of ranking differences (SRD) algorithm for non-ranking environment. It is expedient to elaborate a new algorithm, which overcomes this difficulty. The procedure has been developed by the analogy of SRD, <em>i.e</em>., pairwise comparisons of (column) vectors, fixing one of them as gold standard and introducing two validation steps (the randomization and Wilcoxon tests after assigning uncertainties by cross-validation).<h3>Results</h3>Two emblematic distance metrics were involved in the development: the most frequently applied Euclidean distance and its robust counterpart the city block (Manhattan) distance. Such a way two new dissimilarity measures have been defined: Sum of Euclidean Distance Differences (DnE) and Sum of Absolute Manhattan Distance Differences (DnM) along with their randomization tests and Variance Analysis (ANOVA). Unfortunately, when leaving the safe rank environment, we also leave the well-known permutations and the theoretical backgrounds (Spearman footrule), as well. This study is limited to a maximum of eight rows in the input matrix, where exact theoretical random distributions are available. Sixteen carefully chosen data sets were selected covering a wide range of scientific disciplines and of numbers for columns and rows in the input matrix: between three to 80 and five to eight, respectively. Three case studies illustrate the advantages and disadvantages of the new dissimilarity measures and statistical tests.<h3>Significance</h3>Superior discrimination ability characterizes DnE and DnM; they provide a more sophisticated ranking (and grouping) patterns than SRD despite their smaller visualization (applicability) domain. The randomization test loses its sensitivity in the order of SRD&gt;DnE&gt;DnM. The latter two realize different clustering patterns from SRD and from each other but (almost) the same ordering. Hence, only one of them is recommended in a ranking environment. Although the random distributions of DnE and DnM is distorted a little, the probability of first kind error (say 5%) can safely be determined from the cumulated frequencies. Comprehensive enumeration of advantages and disadvantages has been completed for SRD, DnE and DnM as dissimilarity measures, clustering tools, multicriteria decision making (MCDM) techniques and their competitors. While preserving great advantages of SRD (simplicity, generality, MCDM character and lack of subjective weights), both new techniques are suitable dissimilarity measures, clustering and MCDM tools in non-ranking environments. DnE and DnM also inflict universal scales for later ANOVA and Wilcoxon tests.","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"38 1","pages":""},"PeriodicalIF":6.2,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078069","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":"Direct spectrophotometric method for simultaneous estimation of Plutonium(IV) and nitric acid concentration in PUREX samples via multivariate calibration approach","authors":"Mukesh Kumar ,&nbsp;Saurabh Suman ,&nbsp;K. Dhamodharan ,&nbsp;K.A. Venkatesan","doi":"10.1016/j.aca.2025.344656","DOIUrl":"10.1016/j.aca.2025.344656","url":null,"abstract":"<div><h3>Background</h3><div>The PUREX process aims at quantitative recovery of U and Pu with fission product decontamination factor in the range of 10⁶. For this purpose, process parameters need to be analysed at different process steps. Therefore concentration of Pu and nitric acid in the feed solution must be known before carrying out any process. Conventional analytical techniques for plutonium and nitric acid determination generate significant quantities of secondary radioactive waste and are time-intensive, increasing the radiation exposure risk for personnel especially in facilities handling short-cooled or high burn-up fuels.Hence, there was a need to develop a new method for determination of both the parameter that should be devoid of above disadvantage.</div></div><div><h3>Results</h3><div>An analytical method has been developed for simultaneous determination of Pu(IV) and nitric acid concentration in plutonium nitrate solution for PUREX process samples. Plutonium nitrate absorption spectra changes drastically with the nitric acid concentration. Therefore, without prior knowledge of acidity, quantification of plutonium with direct UV-VIS spectrum is not suitable. Therefore, in present method UV-VIS spectroscopy coupled with chemometric approach being used for utilising these acid induced variations for estimation of nitric acid concentration in a sample along with plutonium concentration. OPLS assisted PCR approach has been used for quantifying the plutonium in the concentration range 1.4–8.4 g/L and nitric acid concentration 1–12 M. OPLS help in making the chemometric model more robust and interpretable. The model has been validated with a test dataset with RMSEV values for prediction of plutonium and nitric acid concentration are 0.24 g/L and 0.21 M respectively.</div></div><div><h3>Significance</h3><div>The developed method is simple, fast and reliable. Also, present method is devoid of any analytical waste as sample after analysis can be mixed with the process stream. This method is direct spectrophotometric method and hence amenable for online monitoring.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344656"},"PeriodicalIF":6.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078066","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":"DNAzyme-activated rolling circle amplification cascade nanomachine for sub-femtomolar detection of tuberculosis single-nucleotide mutation","authors":"Nan Sun ,&nbsp;Tingting Li ,&nbsp;Yulin Yang ,&nbsp;Zhenhua Chen ,&nbsp;Qian Gao ,&nbsp;Haobin Chen ,&nbsp;Zheyuan Zhou ,&nbsp;Bo Tian","doi":"10.1016/j.aca.2025.344666","DOIUrl":"10.1016/j.aca.2025.344666","url":null,"abstract":"<div><h3>Background</h3><div>Tuberculosis (TB) remains a global health crisis, with drug-resistant strains posing significant diagnostic challenges due to the high cost and performance limitations of current methods. Rifampicin-resistant TB (RR-TB), approximately 97% of which are associated with <em>rpoB</em> 531T single-nucleotide mutation, presents a critical target for TB control. Padlock probe ligation-based rolling circle amplification (RCA) enables discrimination of single-nucleotide variants, rendering it a promising approach for detecting TB drug-resistance mutations. However, padlock probe ligation-based RCA achieves only sub-picomolar limits of detection, limiting its application.</div></div><div><h3>Results</h3><div>Herein, we present a multifunctional DNA nanomachine designed for the rapid detection of the <em>Mycobacterium tuberculosis</em> (MTB) <em>rpoB</em> 531 (TCG to TTG) mutation. This nanomachine integrates a DNAzyme-mediated cleavage reaction and RCA within a spatially confined architecture. Specifically, by co-assembling a DNAzyme substrate strand, a DNAzyme catalytic strand, a preformed circular template, and an RCA primer into a single nanostructure, we established a confined reaction microenvironment that minimizes diffusion distances, enabling accelerated reaction kinetics while effectively reducing cross-talk between cascade steps. Leveraging the programmability of DNA nanomachines with detection probe-functionalized magnetic nanoparticles for real-time optomagnetic sensing, our biosensor achieved a detection limit of 0.3 fM with a total assay time of 100 min and exhibited a dynamic detection range spanning 6 orders of magnitude. The biosensor performance was validated using synthetic wild-type sequences, spiked serum samples, and clinical sputum DNA extracts.</div></div><div><h3>Significance and novelty</h3><div>By spatially confining cascade DNA reactions within a single nanostructure, we overcame intrinsic limitations of homogeneous cascade reactions in complex matrices, enabling autocatalytic signal recycling, RCA, nanoparticle clustering, and real-time quantification. This approach offers a robust and cost-effective solution for point-of-care RR-TB diagnosis and demonstrates the potential for detecting other single-nucleotide mutations.</div></div>","PeriodicalId":240,"journal":{"name":"Analytica Chimica Acta","volume":"1377 ","pages":"Article 344666"},"PeriodicalIF":6.0,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078067","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}