Analytical Methods最新文献

{"title":"“On–Off” electrochemical sensing toward mercury pollution in tea via exonuclease III triggered target recycling amplification","authors":"Lili Zhou, Guangyue Hou, Dan Xi, Yue Guo, Yanping Gou, Hanlin Li, Yaning Zhang, Yongxin Mo, Xiaoli Dai, Rongjin Xu, Hany S. El-Mesery and Wenjie Lu","doi":"10.1039/D5AY00683J","DOIUrl":"10.1039/D5AY00683J","url":null,"abstract":"<p >Mercury ion (Hg<small>²⁺</small>) pollution in tea poses significant risks to human health due to its high toxicity, bioaccumulation, and potential to cause neurological and kidney damage. Sensitive monitoring of Hg<small>²⁺</small> in tea is therefore critical for food safety and public health. Here, we developed an electrochemical biosensor for ultrasensitive Hg<small>²⁺</small> assay by integrating thymine–Hg<small>²⁺</small>–thymine (T–Hg<small>²⁺</small>–T) mismatch recognition with exonuclease III (EXO III)-assisted dual signal amplification. The sensing mechanism relies on Hg<small>²⁺</small>-triggered formation of T–Hg<small>²⁺</small>–T structures, which activate EXO III to release Hg<small>²⁺</small> for cyclic reuse while generating reporter DNA (RDNA). Signal amplification is further enhanced by MOF(Zr)/Th/AuPt nanocomposites, where the Zr-based metal–organic framework (MOF(Zr)) and AuPt nanoparticles synergistically catalyze thionine (Th) oxidation, producing a strong electrochemical response. This dual-amplification strategy achieves a detection limit of 4.45 pM, surpassing that of conventional methods. The biosensor demonstrates high specificity against interfering metal ions (<em>e.g.</em>, Cd<small>²⁺</small> and Cu<small>²⁺</small>) and reliable performance in real tea samples (93.7%∼103.4% recovery), offering a promising tool for monitoring Hg<small>²⁺</small> contamination in food products.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 25","pages":" 5292-5297"},"PeriodicalIF":2.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser melting of Parafilm-wax: a novel approach to hydrophobic barrier formation in paper-based microfluidics","authors":"Akshay A. Kamble, Gourav Samal and Bhushan J. Toley","doi":"10.1039/D5AY00725A","DOIUrl":"10.1039/D5AY00725A","url":null,"abstract":"<p >We present a novel method for fabricating microfluidic paper-based analytical devices (μPADs) using laser melting of Parafilm wax to form hydrophobic barriers. This approach involves placing Parafilm on filter paper and patterning it with a CO<small>₂</small> laser, which locally melts the wax to create embedded flow barriers. Crucially, the Parafilm is peeled off post-patterning, preserving both surfaces of the paper and enabling vertical flow assays. Optimal laser parameters were determined to ensure consistent barrier formation without damaging the paper. The technique enabled the fabrication of channels as narrow as 800 μm. Compatibility with biochemical assays was confirmed through colorimetric detection of glucose and protein, and through a vertical flow enzyme-linked immunosorbent assay (ELISA) for human IgG, with a detection limit of 3.9 ng mL<small>⁻¹</small>. This single-step, reflow-free method is simple, reproducible, and accessible, leveraging materials and equipment readily available in standard laboratories. It lowers the technical barriers to μPAD fabrication and enables both planar and vertical assay formats, expanding the scope of paper-based diagnostics for point-of-care applications.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 23","pages":" 4866-4872"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144207141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding synthetic pathways of chemical warfare precursors: advanced impurity profiling of methylphosphonothioic dichloride using GC × GC-TOFMS-chemometrics hybrid platforms†","authors":"Zixuan Zhang, Xiaogang Lu, Meng Jin, Runli Gao and Hongmei Wang","doi":"10.1039/D5AY00870K","DOIUrl":"10.1039/D5AY00870K","url":null,"abstract":"<p >The chemical identification of precursor synthesis pathways is crucial for enforcing the Chemical Weapons Convention (CWC) by facilitating the forensic tracking of organophosphorus nerve agents. This study introduces the initial systematic impurity-profiling platform for methylphosphonothioic dichloride, a critical precursor of V-series CWC-controlled substances. Our analysis identified 58 unique compounds, offering valuable insights using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry in conjunction with advanced chemometric workflows. We devised a hierarchical analytical approach: (1) unsupervised pattern recognition (HCA/PCA) revealed the inherent clustering of two primary synthetic pathways, (2) oPLS-DA modeling achieved 100% classification accuracy (<em>R</em><small>²</small> = 0.990) with 15 VIP-discriminating features, and (3) rigorous validation through permutation tests (<em>n</em> = 2000) and external samples (<em>n</em> = 12) demonstrated 100% prediction accuracy. Notably, traceability was established at impurity levels as low as 0.5%, exceeding the OPCW verification standards. The established impurity database, in combination with the dual-mode chemometric approach, provides a robust framework for identifying chemical warfare-related precursors.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 25","pages":" 5160-5169"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-end self-priming induced cascade amplification system for label-free photosensitization colorimetric detection of microRNA†","authors":"Wenjuan Yi, Yujie Chen, Caiyun Gao, Qiufang Qin and Heping Qin","doi":"10.1039/D5AY00532A","DOIUrl":"10.1039/D5AY00532A","url":null,"abstract":"<p >MicroRNAs (miRNAs) are pivotal regulators in disease progression and have emerged as significant biomarkers for the early detection, therapeutic intervention, and management of ovarian cancer. The integration of highly sensitive and reliable miRNA detection techniques with ultrasound imaging has the potential to significantly improve the diagnostic accuracy of cancers. In this study, we developed a novel colorimetric approach for the sensitive and reliable detection of miRNAs. This method combines self-priming-mediated DNA polymerization with target recycling and a SYBR Green I (SG)-induced colorimetric response. The sensor operates through a three-stage mechanism: (i) target recognition initiates the formation of a self-priming structure; (ii) an exponential isothermal amplification process, driven by DNA polymerase, facilitates signal amplification; and (iii) a photo-catalyzed color change enables label-free signal generation. Using miRNA-21 as a model target, this approach allows for precise miRNA-21 detection without the need for primers, while the SG-based photo-catalyzed color reaction minimizes background signal interference. The sensor demonstrates the ability to distinguish single-base mismatches in homologous sequences and maintains robust performance in complex biological environments. Furthermore, the sensor has been successfully applied to accurately quantify miRNA-21 levels from constructed samples, highlighting its substantial potential for clinical diagnostics and disease monitoring applications.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 24","pages":" 5027-5033"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alternative digestion strategy for Ti, Zr and Hf oxides: eliminating hydrofluoric acid†","authors":"Lukas R. H. Gerken, Matthias Roesslein, Inge K. Herrmann and Alexander Gogos","doi":"10.1039/D5AY00731C","DOIUrl":"10.1039/D5AY00731C","url":null,"abstract":"<p >Group IV metal oxides have a broad impact on the environment and human health due to their diverse applications in industry, consumer products and biomedicine. However, their chemical inertness poses significant challenges for accurate quantification in biological matrices, which is essential for assessing biodistribution, toxicity, and regulatory compliance. Traditional digestion methods often rely on hydrofluoric acid (HF), a hazardous reagent requiring specialized handling and infrastructure. Here, we present an alternative, HF-free microwave assisted digestion protocol for group IV metal oxides in biological contexts, utilizing sulfuric acid/water/hydrogen peroxide mixtures to achieve complete solubilization across nano-to microscale particles. The method's efficacy was evaluated on various commercially available TiO<small>₂</small>, ZrO<small>₂</small>, and HfO<small>₂</small> powders. Optimization of digestion parameters, including acid-to-peroxide ratios, temperature, and reaction time, led to recoveries exceeding 90% for all tested materials. Notably, higher temperatures and extended digestion times were required for larger particles and higher atomic number oxides, reflecting the increased metal–oxygen bond dissociation energies. The method's applicability was further demonstrated through successful quantification of spiked nanoparticles in human cancer cells and bovine liver tissue, with detection limits down to ∼1 ppb and achieving recoveries within 80–100%, maintaining sample stability over four weeks. Comparative analysis with HF-based digestion revealed comparable sensitivity and detection limits using inductively coupled plasma optical emission spectrometry (ICP-OES), with the HF-free method offering a safer and more accessible alternative for routine laboratory analysis. This validated protocol facilitates accurate quantification of group IV metal oxides in complex biological matrices, supporting preclinical and clinical studies while mitigating the risks associated with HF usage.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 26","pages":" 5334-5342"},"PeriodicalIF":2.7,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ay/d5ay00731c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhodamine-based turn-on fluorescent and colorimetric chemosensor for selective Pb2+ detection: insights from crystal structure, molecular docking, real sample analysis, and logic gate applications†","authors":"Ram Kumar, Bholey Singh, Rita Kakkar, Avneesh Mittal and Balaram Pani","doi":"10.1039/D5AY00482A","DOIUrl":"10.1039/D5AY00482A","url":null,"abstract":"<p >Lead (Pb<small>²⁺</small>) contamination remains a critical environmental and public health concern, necessitating its effective detection methods. In this study, we report the design and synthesis of a novel rhodamine-based Schiff base chemosensor (<strong>L</strong>), which demonstrates high selectivity and sensitivity for Pb<small>²⁺</small> ions. The chemosensor exhibited distinct colorimetric and fluorescence responses, providing a practical and efficient approach for detecting Pb<small>²⁺</small> in environmental and biological samples. Upon interaction with Pb<small>²⁺</small> ions in acetonitrile, the sensor exhibited a distinct turn-on fluorescence response along with a noticeable colour change. The binding studies confirmed that sensor <strong>L</strong> bound to lead ions in a 1 : 1 ratio. This was determined using Job's plot and Benesi–Hildebrand (B–H) plot analyses, which also revealed a binding constant (<em>K</em><small>_a</small>) of 0.954 × 10<small>⁴</small> that indicated strong and specific interaction between <strong>L</strong> and Pb<small>²⁺</small> ions. The limit of detection was found to be 3.77 nM for Pb<small>²⁺</small> ions, demonstrating the remarkable sensitivity of the sensor. DFT calculations confirmed the stability of <strong>L</strong>–Pb<small>²⁺</small> complex, where Pb<small>²⁺</small> was coordinated to three atoms of <strong>L</strong>. Molecular docking analyses of <strong>L</strong> with human DNA (5VBN) indicated a binding affinity of −5.7 kcal mol<small>⁻¹</small>, highlighting its potential for DNA interactions and therapeutic use. The successful detection of Pb<small>²⁺</small> in real water samples, solid-state sensing experiments, and filter paper-based assays demonstrated the practical applications of the sensor, highlighting its effectiveness in environmental monitoring.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 23","pages":" 4812-4830"},"PeriodicalIF":2.7,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144197801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasound-enzyme-assisted extraction of flavonols from Polygonatum odoratum using ternary natural deep eutectic solvents","authors":"Yuhan Lou, Jiaying Zhang, Xirui Wu, Jiaxin Li, Qihong Zhou, Wenxiu Li, Luyuan Yang and Bin Guo","doi":"10.1039/D5AY00347D","DOIUrl":"10.1039/D5AY00347D","url":null,"abstract":"<p >Natural deep eutectic solvents (NADESs) are emerging green solvents that show great potential in extracting natural products from natural resources. In this study, a third component was introduced into the NADES system, and the screened ternary NADES (choline chloride/fructose/citric acid, 1 : 1 : 2) was combined with ultrasound-enzyme-assisted extraction to extract flavonols from <em>Polygonatum odoratum</em>. The main flavonol components, including quercetin, kaempferol and isorhamnetin, were determined by high-performance liquid chromatography and analyzed in comparison with the extraction efficiency of traditional procedures. The results of Fourier transform infrared spectroscopy and Raman spectroscopy showed that the alteration of intermolecular forces in NADESs promoted the formation of hydrogen bonds between them and flavonols, which significantly increased the extraction yields. After optimization by single-factor and Box–Behnken experiments, the ternary NADES extraction yields could reach 0.24 mg g<small>⁻¹</small> under the optimal conditions of cellulase dosage 1.1%, ultrasonic time 62 min, ultrasonic temperature 61 °C, and water content 60%. The study provides an efficient and environmentally friendly way to extract flavonols from natural medicinal plants, and also elucidates the potential mechanism of the ultrasound-enzyme-assisted ternary NADESs for the improved extraction efficiency.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 26","pages":" 5412-5422"},"PeriodicalIF":2.7,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A self-priming mediated chain extension cysteine catalytic oxidation-based colorimetric method for sensitive Pseudomonas aeruginosa detection†","authors":"Jiaxiang Xie, Lixia Xia, Juan Huang, Juan Han and Zhining Wang","doi":"10.1039/D5AY00197H","DOIUrl":"10.1039/D5AY00197H","url":null,"abstract":"<p >Nursing hospital infections with <em>Pseudomonas aeruginosa</em> (<em>P. aeruginosa</em>) pose a significant risk to human health, especially to those immunosuppressed patients receiving surgical therapy. Consequently, it is imperative to create a novel and portable <em>P. aeruginosa</em> analysis method for the early diagnosis of <em>P. aeruginosa</em> infections. For sensitive and reliable <em>P. aeruginosa</em> analysis, we depict here a novel colorimetric approach based on rolling circle amplification (RCA) based construction of a detection scaffold and self-priming mediated signal recycling. In this method, the RCA product is attached to a plate surface to recognize <em>P. aeruginosa</em> targets and initiate the chain extension mediated cysteine catalytic oxidation based colorimetric reaction. This method involves activating RCA to generate several RCA products with repetitive functional portions by cyclizing the padlock sequence using primer sequences. To facilitate the color reaction based on gold nanoparticles, the produced G-rich sequences during the self-priming mediated signal recycling process can fold to G-quadruplex DNAzyme, which can catalyze the conversion of cysteine to cystine and produce color changes that can be observed directly with the naked eye. Based on this elegant design, the method has a broad detection range and a low limit of detection of 3.6 cfu mL<small>⁻¹</small>. In addition, this colorimetric approach showed good selectivity to target bacteria. This technology has great potential for use in biomedical diagnostics and bio-sensing of pathogenic bacteria.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 26","pages":" 5459-5465"},"PeriodicalIF":2.7,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144323875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a low-cost equipment alternative to the Kjeldahl distiller for the determination of total volatile basic nitrogen","authors":"Nelson de Abreu Delvaux Júnior, Maria Eliana Lopes Ribeiro de Queiroz, André Fernando de Oliveira, Antônio Augusto Neves, Fernanda Fernandes Heleno, Amanda Maria Leal Pimenta, Flávio Pinto Monção, Flaviano Oliveira Silvério, Fernanda Menezes Maia, Luís Felipe Rodrigues Costa and Luciano Pereira Rodrigues","doi":"10.1039/D5AY00260E","DOIUrl":"10.1039/D5AY00260E","url":null,"abstract":"<p >The determination of the total volatile basic nitrogen content in fish is a method of assessing food quality that is typically carried out using the Kjeldahl distiller. The objective of this project was to develop an alternative equipment configuration to replace the Kjeldahl distillation apparatus. The results obtained are promising, as the ammonia extraction achieved 98% efficiency and the TVB-N content and relative standard deviation were 31.0 mg N per 100 g and 11.6%, respectively. The same samples studied using the traditional method showed TVB-N content and relative standard deviation of 32.5 mg N per 100 g and 12.4%, respectively. It can be concluded that the newly developed low-cost equipment can be useful for determining TVB-N without compromising the results of routine analyses previously obtained exclusively through the Kjeldahl method for evaluating fish quality. In addition, the alternative equipment is safer and allows for a higher analytical frequency compared to the Kjeldahl distiller.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 23","pages":" 4788-4795"},"PeriodicalIF":2.7,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144155283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Conditional regulation of HCR for rapid visualization of endogenous miR-21 in cancer cells†","authors":"Chunyu Yan, Juan Du, Yan Zhang, Lu Miao and Zhaochao Xu","doi":"10.1039/D5AY00542F","DOIUrl":"10.1039/D5AY00542F","url":null,"abstract":"<p >MicroRNA-21 (miR-21) is a significant tumor marker for early cancer screening. Hybridization chain reaction (HCR) as an enzyme-free signal amplification method has been used for intracellular miR-21 detection in living cells, but it is limited by unclear reaction details and prolonged detection time. In this study, by effectively regulating the HCR reaction conditions, we achieved rapid visualization of endogenous miR-21 in live cells. A pair of HCR DNA hairpins H<small>₁</small> and H<small>₂</small> was designed, and the effects of reaction concentration, the type of HCR products, ionic selectivity, and the reaction order of H<small>₁</small> and H<small>₂</small> on the HCR process were investigated. We discovered that the cascade reaction produced by HCR in cells primarily formed six distinct assemblies and was dependent on different concentrations of Na<small>⁺</small> and Mg<small>²⁺</small> salts. Importantly, it was found that the addition sequence of the two hairpin DNAs was closely related to the speed of the cascading reaction in living cells. Adding H<small>₁</small> first and then H<small>₂</small> resulted in stronger detection signals in a relatively short time. By elucidating these details, we carried out the rapid fluorescence colocalization detection of endogenous miR-21 in living cells.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" 25","pages":" 5170-5175"},"PeriodicalIF":2.7,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}