Analytical Methods最新文献

{"title":"Label-free and ultrasensitive electrochemical detection of nucleic acids based on an exonuclease III-assisted target recycling amplification strategy using a heated gold disk electrode.","authors":"Yanggang Cheng, Minglu Liu, Fangfang Wang","doi":"10.1039/d4ay01619j","DOIUrl":"https://doi.org/10.1039/d4ay01619j","url":null,"abstract":"<p><p>The present work demonstrates a label-free, rapid and ultrasensitive electrochemical sensor for specific DNA detection with an exonuclease III (Exo III)-assisted target recycling amplification strategy and elevated electrode temperature at a heated gold disk electrode (HAuDE). The proposed electrochemical DNA (E-DNA) sensor was designed such that in the presence of the target DNA, the electrode self-assembled capture probe hybridizes with the target DNA to form a duplex structure, which triggers Exo III to specifically recognize this structure and selectively digest the capture probe, while the released target DNA underwent recycling to hybridize with a new capture probe, leading to the gradual digestion of a large amount of capture probes. It was found that during the digestion period, the activity of Exo III could be significantly improved by elevating electrode temperature, thus promoting the digestion reaction and improving the sensitivity for target DNA detection. Furthermore, an electrochemical indicator ([Ru(NH₃)₆]³⁺) was electrostatically bound to the capture probe, leading to a significant square wave voltammetry (SWV) response, which directly related to the amount and length of the capture probes remaining in the electrode and provided a quantitative measure for target DNA detection. The proposed strategy realized the highly sensitive detection of the target DNA with a detection limit of 26 aM (S/N = 3) at an electrode temperature of 40 °C during the digestion period, which was about two magnitudes lower than that at 24 °C.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453554","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":"Molecularly imprinted polymer on cotton materials as substrates for smartphone-based image and distance-based analysis of Cu(II) in water samples.","authors":"N Thongkon, Phakamas Maisom, Orawan Taewcharoen, Wannaree Kamsomjit, Supacha Nilsuwan, Nattakul Saejan, S Somrak","doi":"10.1039/d4ay01552e","DOIUrl":"https://doi.org/10.1039/d4ay01552e","url":null,"abstract":"<p><p>Cotton fabric was used as a substrate for smartphone-based image analysis of Cu(II) in drinking water. To enhance its selective and specific binding sites on the cotton surface, a molecularly imprinted polymer (MIP) was introduced using color complexes of 4-(2-pyridylazo)resorcinol-Cu(II) (PAR-Cu(II)) as the template molecule, 3-aminopropyltriethoxysilane (APTES) as the functional monomer, tetraethoxysilane (TEOS) as the crosslinker and NH₃ as the catalyst. After achieving optimum conditions, the obtained CF-MIP/PAR-Cu(II) presented a red color, which was changed to yellow upon the removal of Cu(II) with 1.5 M HCl. After using CF-MIP/PAR to detect Cu(II), the red, green and blue intensities of the images captured using a smartphone were analyzed using the ImageJ program. For the calibration curve plotted between Δgreen intensity and Cu concentration, the linear range was 0.10-1.0 mg L^-1 with the best correlation coefficient (<i>R</i>²) of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) were found to be 0.038 and 0.11 mg L^-1, respectively. To obtain a distance-based device, MIP-modified cotton thread (CT-MIP/PAR) with a four-channel design was used as an alternative device. The distance of red color development was measured after using CT-MIP/PAR to detect Cu(II). The linear range was 0.50-3.0 mg L^-1 with an <i>R</i>² of 0.997. The LOD and LOQ were 0.18 and 0.56 mg L^-1, respectively. The proposed methods provide simple, portable and inexpensive devices with high accuracy and precision for the detection of Cu(II) in drinking water.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453555","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 ratiometric fluorescence nanosensor for glutathione detection based on spatially confined dual-emission of α-lipoic acid-modified gold nanoclusters and silicon nanoparticles.","authors":"Abdullah S Albalawi, Alanoud Alkhamali, Mohamed M El-Wekil, Ramadan Ali","doi":"10.1039/d4ay01525h","DOIUrl":"https://doi.org/10.1039/d4ay01525h","url":null,"abstract":"<p><p>The development of dual-emission ratiometric fluorescent probes with aggregation-induced emission enhancement (AIEE) overcomes the limitations of gold nanocluster (Au NC)-based probes, particularly their weak intrinsic fluorescence, in real-world applications. These AIEE probes also exhibit superior detection limits and enhanced sensitivity. A novel combination for the reliable fluorometric detection of glutathione (GSH) was proposed, utilizing aggregation-induced emission enhancement (AIEE) facilitated by electrostatic interaction and spatial confinement. The probe consists of a ratiometric combination of negatively charged α-lipoic acid-modified Au NCs (LA@Au NCs) and positively charged silicon nanoparticles (SiNPs). The addition of SiNPs causes aggregation of LA@Au NCs, enhancing the fluorescence of LA@Au NCs through the AIE effect under electrostatic interaction and spatial confinement. The addition of Cu²⁺ quenched the emission of LA@Au NCs as a result of charge transfer. The fluorescence emissions of LA@Au NCs were restored upon the addition of GSH due to the interaction between GSH and Cu²⁺. Simultaneously, the emission signal of SiNPs remains unchanged, serving as an internal reference signal during GSH measurement. It was found that the fluorescence ratio (<i>F</i>₆₈₀/<i>F</i>₄₆₅) is directly proportional to the concentration of GSH in the range of 0.05-100 μM, with a detection limit of 1.7 nM (S/N = 3). The proposed system was applied to detect GSH in real samples, including dietary supplements, human serum, and saliva samples. This work opens new avenues for constructing novel sensors based on AIEE for detecting biomolecules.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453540","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":"Removal and measurement of trace amounts of rhodamine B in aqueous samples based on the synthesis of a nanosorbent composed of Fe₃O₄ nanoparticles modified with SiO₂ and polydopamine by magnetic solid phase extraction.","authors":"Abdollah Yari, Mariam Salemzadeh","doi":"10.1039/d4ay01537a","DOIUrl":"https://doi.org/10.1039/d4ay01537a","url":null,"abstract":"<p><p>Rhodamine B (RDB) dye is generally toxic and causes problems such as carcinogenic activities, neurological disorders, and respiratory tract irritations. However, some individuals still illegally use RDB as a food additive. Therefore, a simple and accurate method is needed to determine RDB in real samples such as food or cosmetic products. In this study, the magnetic solid phase extraction (MSPE) method was used to measure very low amounts of RDB dye in water samples. The advantages of this method include simplicity, good repeatability, high preconcentration factor, higher extraction efficiency, low organic solvent volume requirement, rapid separation, low cost, high sensitivity, and interference removal compared to other methods. Within this approach, iron oxide nanoparticles were synthesised, followed by the application of tetra ethoxy silane (TEOS) and polydopamine (PDA) coatings on the nanoparticle surface, resulting in the creation of the Fe₃O₄@SiO₂@PDA nano-sorbent. This nano-sorbent was then utilized as the magnetic solid phase in MSPE. The characteristics of the synthesized compounds were investigated by various methods such as infrared Fourier transform spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and vibrating sample magnetometry (VSM). Response surface methodology (RSM) and Box-Behnken (BB) design were used to optimize the variables affecting the adsorption process and achieved high recovery percentages. Under optimal experimental conditions, the detection limit and quantification limit of the method were found to be 0.73 and 2.42 μg L^-1 for RDB, respectively, with RSDs of ±0.32% and ±0.67%. Furthermore, the linear concentration range of the proposed method for solid phase extraction of RDB was determined to be 10.0-900.0 μg L^-1. Moreover, the recovery rates for tap water, lake water, and well water samples ranged from 96.9% to 98.6%.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405744","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":"Application of a metabolomics method in the study of pear fruit storage.","authors":"Jing Liu, Zixuan Meng, Baoru Liu, Jing Wang, Haichao Zhang, Lianfeng Ai, Junfeng Guan, Lingmei Niu","doi":"10.1039/d4ay01368a","DOIUrl":"https://doi.org/10.1039/d4ay01368a","url":null,"abstract":"<p><p>The entire transportation process of 'crown' pears from harvest to consumption is primarily refrigerated. However, the impact of refrigeration time and temperature on fruit quality remains unclear. In this study, metabolites of 'crown' pears were analyzed using UHPLC-Q-Exactive and GC-MS/MS techniques under cold storage, at room temperature, and at different cold storage durations. A total of 372 substances were identified, including sugars, amino acids, and flavonoids, among others. Among these substances, 27 were identified as significant biomarkers affecting pear quality. An accurate quantitative method for amino acids was established to systematically verify the change trend of L-aspartic amide, glycine, glutamic acid, and other amino acids. The results indicated that after 30 days of storage at 0 °C, there was a relatively small change in the quality and substance content of 'crown' pears with little effect on their nutritional value. These findings could serve as a reference for optimizing the refrigeration time and temperature for pear fruit.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398737","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":"Solid substrate assisted enhanced laser induced breakdown spectroscopy for metal element analysis in aqueous solution.","authors":"Linna Song, Jianwen Han, Mingda Sui, Zihao Wei, Yunpeng Qin, Yuan Lu, Jiaojian Song, Wangquan Ye, Jinjia Guo","doi":"10.1039/d4ay01551g","DOIUrl":"https://doi.org/10.1039/d4ay01551g","url":null,"abstract":"<p><p>Due to plasma quenching caused by the dense water medium, laser-induced breakdown spectroscopy (LIBS) faces challenges such as strong continuous background radiation and weak and broadened characteristic spectral lines when directly detecting metal elements in liquids. In this work, we introduced a simple approach to improve underwater LIBS signals with a solid substrate-assisted method, which requires no sample pre-treatment and simple operation and thus has potential for <i>in situ</i> marine applications. In this method, four submerged solid substrates (Zn, Cu, Ni, and Si) were employed to investigate the breakdown characteristics of underwater LIBS and the mechanism of spectral enhancement by using a CaCl₂ solution. The results demonstrated a significant improvement in the detection sensitivity of Ca with these substrates even at a short laser pulse with a relatively low laser energy (10 mJ). Among them, the semiconductor Si substrate exhibited the best enhancement effect, with an enhancement factor of over 75 for the Ca ionic lines at 393.4 nm and 396.8 nm and an enhancement factor of 29 for the Ca atomic line at 422.7 nm, respectively. This is mainly because the presence of substrate decreases the breakdown threshold of the liquid sample, and a higher plasma excitation temperature and electron density are obtained, which, in turn, leads to higher signal intensity. Furthermore, significant plasma emission enhancements for a wide range of elements are also achieved from seawater. These findings can contribute to the development of compact underwater <i>in situ</i> LIBS sensors with low power consumption, while ensuring high detection sensitivity.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453559","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":"Integrated instrumental setup comprising an automatic solution handling module and homemade luminometer with two photodetectors for the determination of antioxidants in wines.","authors":"Rafael A Alexandre, Boaventura F Reis","doi":"10.1039/d4ay01597e","DOIUrl":"https://doi.org/10.1039/d4ay01597e","url":null,"abstract":"<p><p>This study describes the development of an integrated instrumental setup, comprising a multi-commuted flow analysis module for solution handling and a homemade luminometer assembled with two photodetectors for luminescence detection. This setup controlled by an Arduino Due board was used to develop an analytical procedure for determining antioxidants in red and white wines, using chemiluminescence detection. The analytical procedure is based on the reaction of hypochlorite with antioxidants present in wine, followed of oxidizing reaction with luminol in an alkaline medium (pH > 9). After determining the optimal operational parameters, the following analytical parameters were obtained: linear responses for gallic acid concentrations ranging from 0.75 to 4.0 g L^-1 (<i>r</i>² = 0.999) for red wine and from 75 to 500 mg L^-1 (<i>r</i>² = 0.994) for white wine, a coefficient of variation of 2.71% (<i>n</i> = 9) for a wine sample with an antioxidant concentration of 1.57 g L^-1 in gallic acid equivalent, recoveries ranging from 85 to 114%, an analytical throughput of 100 determinations per hour, consumption of 0.35 μg of hypochlorite and 53 mg of luminol per determination, and limits of detection of 0.25 g L^-1 and 29 mg L^-1 for red and white wine, respectively.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453553","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":"Establishment and characterization of noro-VLP measurement by digital ELISA","authors":"Takema Hasegawa, Yuriko Adachi, Kazumi Saikusa and Megumi Kato","doi":"10.1039/D4AY01012D","DOIUrl":"10.1039/D4AY01012D","url":null,"abstract":"<p >Highly sensitive viral analytical techniques are essential tools for preventing the spread of infections. In this study, we established a digital enzyme-linked immunosorbent assay (ELISA) system to quantify norovirus proteins with high sensitivity. We used norovirus-like particles (noro-VLPs) as a surrogate for norovirus and constructed two digital ELISA systems using two different antibody pairs. The quantitative performance of the noro-VLP measurement using each digital ELISA system was evaluated. Both assay systems exhibited high sensitivity, good linearity, and high stability. The first system exhibited a limit of detection (LOD) of 87 pg mL<small>⁻¹</small> and correlation coefficient (<em>R</em><small>²</small>) of 0.9984. Analysis of samples containing 5 ng per mL noro-VLP confirmed inter-assay variation of 5.5%, and intra-assay variation of 5.2%. The second system exhibited an LOD of 19 pg mL<small>⁻¹</small> and <em>R</em><small>²</small> of 0.9984. Analysis of samples containing 5 ng per mL noro-VLP confirmed inter-assay variation of 4.5%, and intra-assay variation of 2.5%. Comparison of the two systems using the same calibrant for unpurified and fractionated noro-VLPs revealed that the quantitative values for unpurified noro-VLPs were the same, whereas those for fractionated noro-VLPs were dramatically different. Our findings indicate that the reactivity to various components in the noro-VLP solution was altered depending on the different antibodies. Furthermore, our study highlights the importance of using appropriate calibrants, which contain the same ratio of components as the noro-VLP analyte, to afford accurate measurements.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453551","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":"Fruit waste-derived carbon dots with rhodamine B for the ratiometric detection of Fe3+ and Cu2+†","authors":"Junyu Zhang, Yi Chen, Yiyang He, Yiwen Bai, Wei Wang, Guangxin Yang, Cong Kong, Xiao Cao and Lin Gu","doi":"10.1039/D4AY01539H","DOIUrl":"10.1039/D4AY01539H","url":null,"abstract":"<p >A green and eco-friendly solvothermal approach is proposed for the synthesis of carbon quantum dots (CQDs) from watermelon rind. The as-prepared CQDs exhibited superior teal fluorescence in aqueous solutions, with a quantum yield of 13.9%. The CQDs and rhodamine B (RhB) were demonstrated to selectively react with Fe<small>³⁺</small> and Cu<small>²⁺</small>, leading to a fluorescence (FL) quenching effect, which was successfully used for constructing “double-response-off” type ratiometric FL probes. A comparative study was conducted to assess the sensitivity and accuracy of ratiometric fluorescent probes, specifically those based on CQDs alone and in combination with RhB, for the selective detection of Fe<small>³⁺</small> and Cu<small>²⁺</small>. By plotting the ratio of the differential fluorescence (Δ<em>F</em>) signals of CQDs to that of RhB against the practical application analyte concentration, the detection limits for Fe<small>³⁺</small> (1.75 μM) and Cu<small>²⁺</small> (0.43 μM) were markedly improved. The quenching mechanism was further explored, and the detection of Fe<small>³⁺</small> and Cu<small>²⁺</small> in surface water was demonstrated, showcasing the potential of efficient and effective nanosensors based on a static quenching effect. Futhermore, the addition of ascorbic acid can restore the fluorescence quenched by Fe<small>³⁺</small>. Therefore, in the presence of copper and iron, the ratiometric probe can demonstrate the ability to identify two different metals.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370266","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":"Correction: Selective fluorescence detection of acetylsalicylic acid, succinic acid and ascorbic acid based on a responsive lanthanide metal fluorescent coordination polymer","authors":"Guo-Ying Chen, Mao-Ling Luo, Li Chen, Jia-Li Wang, Tong-Qing Chai, Dan Wang and Feng-Qing Yang","doi":"10.1039/D4AY90110J","DOIUrl":"10.1039/D4AY90110J","url":null,"abstract":"<p >Correction for ‘Selective fluorescence detection of acetylsalicylic acid, succinic acid and ascorbic acid based on a responsive lanthanide metal fluorescent coordination polymer’ by Guo-Ying Chen <em>et al.</em>, <em>Anal. Methods</em>, 2024, <strong>16</strong>, 4981–4994, https://doi.org/10.1039/d4ay00696h.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ay/d4ay90110j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142370265","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}