Analyst最新文献

{"title":"Photoelectrochemical signal polarity transition mediated by quercetin for the detection of neuron specific enolase","authors":"Rui Xu, Chenyu Jiang, Qin Wei","doi":"10.1039/d4an00764f","DOIUrl":"https://doi.org/10.1039/d4an00764f","url":null,"abstract":"A photoelectrochemical (PEC) biosensor with a wide detection linear range was developed for neuron-specific enolase (NSE) sensitive detection, which realized by a photocurrent polarity transition strategy mediated by quercetin. The coupling reaction between Cr(Ⅵ) and quercetin drive the signal polarity from anodic to cathodic. When quercetin in the test solution only, the photogenerated electrons transferred to the electrode to generate anodic photocurrent. When the target was detected, the signal probe was treated and released Cr(Ⅵ), which interact with quercetin and the electrons transfer direction was changed to achieve signal polarity conversion. Meanwhile, protoporphyrin-sensitized Bi: SrTiO3 nanocubes were used as the matrix photoactive materials to provide basic photocurrent. The doping of Bi element would prefer the bandgap of SrTiO3, and the organic-inorganic composite material has good photostability and chemical stability, that can maintain stable photoelectric properties over a long period of time. Such a novelty signal polarity transition strategy greatly broadened the sensor detection range of 0.00007 ~170 ng/mL and obtained a relative low detection limit (25 fg/mL), which greatly improved the detection sensitivity and accuracy of the biosensor","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462635","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":"CRISPR-Cas12a-based ultrasensitive assay for visual detection of SARS-CoV-2 RNA","authors":"Shaohua Gong, Kexin Song, Wei Pan, Na Li, Bo Tang","doi":"10.1039/d4an00479e","DOIUrl":"https://doi.org/10.1039/d4an00479e","url":null,"abstract":"The development of ultrasensitive and visual method is of great significance for molecular diagnosis at the point-of-care. In this study, we have integrated recombinase polymerase amplification (RPA) with the CRISPR-Cas12a system to design an ultrasensitive strategy for visual nucleic acid testing. RPA is utilized to amplify the target nucleic acid, producing amplicons that activate the single-stranded DNase property of CRISPR-Cas12a. The activated CRISPR-Cas12a then degrades the single-stranded DNA on magnetic nanoparticles (MNPs), releasing immobilized GOx from MNPs for catalyzing the chromogenic substrate. The developed method exhibits remarkable sensitivity, successfully detecting as low as 10 aM (~6 copies/μL) of the target nucleic acid by visual colour changes in solution. The instrumental limit of detection is calculated to be 2.86 aM (~2 copies/μL), comparable to the sensitivity of polymerase chain reaction (PCR). Importantly, this approach only requires isothermal incubation operation and does not involve costly instruments. The method has been validated by visually detecting the SARS-CoV-2 RNA gene fragment within 50 minutes. With its ultrasensitivity, simplicity of operation, and potential for integration into a point-of-care detection kit, this strategy holds great promise for nucleic acid testing in various settings.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461735","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":"Probe Oscillation Control in Tapping-mode Scanning Probe Electrospray Ionization for Stabilization of Mass Spectrometry Imaging","authors":"Mengze Sun, Yoichi Otsuka, Maki Okada, Shuichi Shimma, Michisato Toyoda","doi":"10.1039/d4an00712c","DOIUrl":"https://doi.org/10.1039/d4an00712c","url":null,"abstract":"Mass spectrometry imaging (MSI) is used for visualizing the distribution of components in solid samples, such as biological tissues, and requires a technique to ionize the components from local areas of the sample. Tapping-mode scanning probe electrospray ionization (t-SPESI) uses an oscillating capillary probe to extract components from a local area of a sample with a small volume of solvent and to perform electrospray ionization of those components at high speed. MSI can be conducted by scanning the sample surface with a capillary probe. To ensure stable extraction and ionization for MSI, the probe oscillation during measurements must be understood. In this study, we examined the changes in oscillation amplitude and phase due to the interaction between the oscillating probe and the brain tissue section when the probe tip was dynamically brought close to the sample surface. The changes in the probe oscillation depended on the oscillation frequency and polarity of the bias voltage applied to the solvent because an electrostatic force shifted the frequency of the probe oscillation. These findings suggest that controlling the probe oscillation frequency is important for stabilizing MSI by t-SPESI.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461578","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-Calibrating Flexible SERS Substrate Incorporated PB@Au Assemblies for Reliable and Reproducible Detection","authors":"Jie Zhou, Huiting Wang, Yaxian Chen, Dongxue Lin, Ling Zhang, Zhi-Qiang Xing, Qian Zhang, Jiarui Xia","doi":"10.1039/d4an00151f","DOIUrl":"https://doi.org/10.1039/d4an00151f","url":null,"abstract":"Precise quantitative analysis of surface-enhanced Raman spectroscopy (SERS) in uncontrollable environment still faces a significant obstacle due to the poor reproducibility of Raman signals. Herein, we propose a facile method to fabricate self-calibration substrate based on flexible Polyvinyl Alcohol (PVA) film comprising assemblies of Prussian blue (PB) and Au NPs (PB@Au) for reliable detection. The PB cores were coated with Au shell through a simple electrostatic interaction, forming the core-shell nanostructure PB@Au assemblies within the PVA. The Au outer layer provided identical trends in enhancement for both PB core and neighboring targets, while PB cores served as internal standard (IS) to correct the signal fluctuations. The prevention of competitive adsorption on the metal surface between targets and ISs was achieved. The proposed PVA/PB@Au film exhibited enhanced stability of Raman signals after IS correction, resulting in improved spot-to-spot and batch-to-batch reproducibility with significantly reduced standard deviation (RSD) values from 11.42% and 25.02% to 4.43% and 9.39%, respectively. Simultaneously, higher accuracy in quantitative analysis of 4-mercaptobenzoic acid (4-MBA) and Malachite green (MG) were achieved with the fitting coeffcient (R<small>²</small>) values improving from 0.9675 and 0.9418 to 0.9974 and 0.9832, respectively. Moreover, the PVA/PB@Au film was successfully applied to detect the residual MG from real-life fish. This work provides an avenue to improve the reproducibility of Raman signals for flexible SERS substrates in detection of residue under varied and complex conditions.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461660","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":"Facile, Green and Scalable Synthesis of Single-Layer Manganese Dioxide Nanosheets and its Applications for GSH and cTnl Colorimetric Detection","authors":"Yao Xiao, Taomei Peng, Yuxiao Luo, Lei Jiao, Taixing Huang, He Li","doi":"10.1039/d4an00689e","DOIUrl":"https://doi.org/10.1039/d4an00689e","url":null,"abstract":"Manganese dioxide (MnO2) nanosheets possess unique physical and chemical properties, making them widely applicable in various fields such as chemicals and biomedicine. Although MnO2 nanosheets have been produced by bottom-up wet chemistry synthesis methods, their scale is below the gram level an requires a long processing time, restricting their effective application from laboratory to market. We report a facile, green method and scalable synthesis of MnO2 nanosheets by mixing Shiranui mandarin orange juice and KMnO4 for 30 minutes. We produced more than a grams (1.095) of MnO2 nanosheets with 0.65 nm mean thickness, 50 nm mean lateral size. Furthermore, we established a visual colorimetric biosensing strategy based on MnO2 nanosheets for assay of glutathione (GSH) and Cardiac troponin I (cTnI), emerging high sensitivity and feasibility in clinical sample. GSH with a limit of detection of 0.08 nM and cTnI with a limit of detection of 0.70 pg mL-1. Meanwhile, it can be real-time monitored by smartphone-enabled biosensing strategy, which can provide a realize point-of-care testing in remote areas.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462447","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":"Thermogravimetry-Synchronized, Reference-Free Quantitative Mass Spectrometry for Accurate Compositional Analysis of Polymer Systems Without Prior Knowledge of Constituents","authors":"Yusuke Hibi, Shiho Uesaka, Masanobu Naito","doi":"10.1039/d4an00624k","DOIUrl":"https://doi.org/10.1039/d4an00624k","url":null,"abstract":"Compositional analysis (CA)—identification and quantification of the system constituents—is the most fundamental and decisive approach to investigate the system of interest. Pyrolysis mass spectrometry (MS) with high resolution over 10,000 is very effective for chemical identification and directly applicable to polymer materials regardless of their solubilities; however, it is less helpful for quantification especially when the references, i.e., pure constituents, are unknown, non-isolable and thus unpreparable. To compensate this weakness, herein we propose reference-free quantitative mass spectrometry (RQMS) with enhanced quantification accuracy assisted by synchronized thermogravimetry (TG). The key to success lies in correlating the instantaneous weight loss from TG with MS signal, enabling the quantitative evaluation of the distinct ionization efficiency for each fragment individually. The determined ionization efficiencies allow conversion of MS signal intensities of pyrolyzed fragments into weight abundances. In a benchmark test using ternary polymer systems, this new framework named TG-RQMS demonstrates accurate CA within ±1.3 wt% errors without using any knowledge nor spectra of the references. This simple yet accurate and versatile CA method would be an invaluable tool to investigate polymer materials whose composition is hardly accessible via other analytical methods.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453014","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":"Robust methodology for PEC performance analysis of photoanodes using machine learning and analytical data","authors":"Moeko Tajima, Yuya Nagai, Siyan Chen, Zhenhua Pan, Kenji Katayama","doi":"10.1039/d4an00439f","DOIUrl":"https://doi.org/10.1039/d4an00439f","url":null,"abstract":"Machine learning (ML) is increasingly applied across various fields, including chemistry, for molecular design and optimizing reaction parameters. Yet, applying ML to experimental data is challenging due to the limited number of synthesized samples, which restricts its broader application in device development. In energy-harvesting, photoanodes are crucial for solar-driven water splitting, generating hydrogen and oxygen. We explored electrodes like hematite and bismuth vanadate for photocatalytic uses, noting varied photoelectrochemical performances despite similar preparations. To understand this variability, we applied a data-driven ML approach, predicting photocurrent values and identifying key performance influencers even with limited experimental data in the research development of inorganic device. Traditional ML methods used multiple algorithms, obscuring the influence of specific factors. We introduced a novel methodology, incorporating clustering to manage multicollinearity from correlated analytical data and Shapley analysis for clear interpretation of contributions to performance prediction. This method was validated on hematite and bismuth vanadate, showing superior predictability and factor identification, then extended to tungsten oxide and bismuth vanadate heterojunction photoanodes. Despite their complexity, our approach achieved determination coefficients (R2) with a prediction accuracy over 0.85, successfully pinpointing performance-determining factors, demonstrating the robustness of the new scheme in advancing photodevice research.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452916","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":"Additive Manufactured Paper-PMMA Hybrid Microfluidic Chip for Simultaneous Monitoring of artificial urine Creatinine and pH.","authors":"Asim Syed Sheeraz, Edoth Aiswarya, B. N. Kumara, Joseph Sonia, Relisha Viyona Rodrigues, Nazmin Sheikh, Sachin Vidhyasagar, RACHANA A KUNDER, Selvakumar Elangovan, Priti Sundar Mohanty, K. Sudhakara Prasad","doi":"10.1039/d4an00796d","DOIUrl":"https://doi.org/10.1039/d4an00796d","url":null,"abstract":"Nowadays, kidney dysfunction is becoming a common health issue due to the modernized lifestyle. Even though medications are commercially available to treat kidney diseases, early diagnosis is vital and challenging. Clinically, measuring urine creatinine and pH has gained significant interest as a way to diagnose kidney diseases early. In the present work, we have attempted to develop a low-cost, robust, accurate and naked-eye colorimetric method to determine both creatinine levels and pH variations in an artificial urine samples using simple 3D-printed hybrid microfluidic device. Creatinine presence was identified by incorporation of traditional Jaffe test onto the hybrid paper–PMMA microfluidic device and pH (4-8) have been identified by utilizing simple anthocyanin test. Notably, the tests were established without employing any sophisticated or costly instrument clusters. The developed 3D-printed microfluidic probe showed a limit of detection (LOD) of 0.04 mM for creatinine over a concentration range of 1-10 mM, with a regression coefficient (R2) of 0.995 in the laboratory conditions. Interestingly the experimental data with artificial urine exhibited a wide linear range from 0.1 mM to 5 mM under different pH value ranging from 4 to 8 in the presence of matrices other than proteins commonly found in patient urine samples, which point towards the potential use for present method for pre-clinical analysis. Since the wide linear range under artificial urine samples falls well below the clinically relevant concentrations of urine creatine in humans (0.07-0.27 mM), the developed lab-on-chip device is further suitable for clinical evaluation with proper ethical clearance. The 3D-printed hybrid microfluidic colorimetry based creatinine detection and pH indicator platform could be beneficial in the healthcare sector due to the on-spot testing capabilities, cost-effectiveness, ease of use, robustness, and instrument-free approach.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452912","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":"Optical control of nanobody-mediated protein activity modulation with a photocleavable fluorescent protein.","authors":"Mizuki Endo, Saki Tomizawa, Qiaoyue Kuang, Takeaki Ozawa","doi":"10.1039/d4an00433g","DOIUrl":"https://doi.org/10.1039/d4an00433g","url":null,"abstract":"<p><p>Antibodies are crucial in various biological applications due to their specific binding to target molecules, altering protein function and structure. The advent of single-chain antibodies such as nanobodies has paved the way for broader applicability in both research and therapies due to their small size and efficient tissue penetration. Recently, several approaches have been reported to optically control the antigen-binding affinity of nanobodies. Here, we show an alternative strategy for creating photo-activatable nanobodies. By fusing the photocleavable protein PhoCl with the N-terminus of the nanobody (named optoNb60), we successfully demonstrated light-dependent restoration of the antigen-binding ability and the following modulation of the activity of a target protein, the beta-2 adrenergic receptor. Moreover, the activation of optoNb60 was monitored by the fluorescence changes upon photoconversion. The compatibility of the uncaging design with the previously reported optogenetic molecules using nanobodies will contribute to the further optimization of the response capabilities of existing optogenetic tools, thereby expanding their applicability.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445592","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":"Comprehensive Review on Fluorescent Carbon Dots and Their Applications in Nucleic Acid Detection, Nucleolus Targeted Imaging and Gene Delivery","authors":"Selva Sharma Arumugam, Nae Yoon Lee","doi":"10.1039/d4an00630e","DOIUrl":"https://doi.org/10.1039/d4an00630e","url":null,"abstract":"Carbon dots (CDs), including carbon quantum dots, graphene quantum dots, carbon nanodots, and polymer dots, have gained significant attention due to their unique structural and fluorescence characteristics. This review provides a comprehensive overview of the classification, structural characteristics, and fluorescence properties of CDs, followed by an exploration of various fluorescence sensing mechanisms and their applications in gene detection, nucleolus imaging, and gene delivery. Furthermore, the functionalization of CDs with diverse surface ligand molecules, including dye molecules, nucleic acid probes, and metal derivatives for sensitive nucleic acid detection is systematically examined. Fluorescence imaging of cell nucleolus plays a vital role in examining intracellular processes and dynamics of subcellular structures. By analyzing the mechanism of fluorescence and structure-function relationships inherent in CDs, the nucleolus targeting abilities of CDs in various cell lines have been discussed. Additionally, challenges such as the insufficient organelle specificity of CDs and the inconsistent mechanisms underlying nucleolus targeting have also been highlighted. The unique physical and chemical properties of CDs, particularly their strong affinity toward deoxyribonucleic acid (DNA), have spurred interest in gene delivery applications. The use of nuclear targeting peptides, polymers, and ligands in conjunction with CDs for improved gene delivery applications have been systematically reviewed. Through a comprehensive analysis, the review aims to contribute to a deeper understanding of the potentials and challenges associated with CDs in biomedical applications.","PeriodicalId":63,"journal":{"name":"Analyst","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452921","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}