Sensors & diagnostics最新文献

{"title":"Flexible & transparent breath sensor and conducting electrodes based on a highly interconnected Au nanoparticle network","authors":"Namuni Sneha, S. Kiruthika","doi":"10.1039/d3sd00330b","DOIUrl":"https://doi.org/10.1039/d3sd00330b","url":null,"abstract":"In this study, transparent humidity sensors and conducting electrodes (TCEs) were fabricated using a highly interconnected gold nanoparticle network (Au nanonetwork) <em>via</em> a simple solution approach. Here, the direct reduction of metal anions at lower temperatures (5 °C) followed by the addition of a non-polar solvent facilitates the cold welding of nanoparticles at junctions and yields an interconnected Au nanonetwork at the liquid–liquid interface. The formed Au nanonetwork is cautiously transferred to the desired flexible, stretchable, and transparent substrates for various applications. As the synthesis involves no capping agents, the prepared nanonetworks offer high conductivity without further chemical or thermal treatments. The fabricated Au nanonetwork is highly crystalline and thermally stable, with excellent mechanical robustness towards various deformations. Using an Au-1L (1-layer) nanonetwork, a highly transparent (&gt;85%) humidity sensor is fabricated with short response and recovery times (1.1 s and 1.3 s). The Au-1L sensor is studied systematically for various humidity changes (40% to 90%) and breath conditions (normal/deep, hydrated/dehydrated, breathing/blowing, <em>etc.</em>) and exhibits high selectivity toward humidity. Notably, the sensing device offered a stable response for more than a year demonstrating its robustness for prolonged use.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved point-of-care detection of P. gingivalis using optimized surface-enhanced Raman scattering in lateral flow assays†","authors":"Lyndsay N. Kissell, Daewoo Han, Der Vang, Alexander W. R. Cikanek, Andrew J. Steckl and Pietro Strobbia","doi":"10.1039/D4SD00056K","DOIUrl":"10.1039/D4SD00056K","url":null,"abstract":"<p >The introduction of surface-enhanced Raman scattering (SERS) in lateral flow assays (LFA) has been recently exploited to increase the sensitivity and quantification capabilities of these rapid tests. Herein, we took advantage of a SERS–LFA combination to improve LFAs designed to test for <em>P. gingivalis</em>, a biomarker for oral health. We have demonstrated a limit of detection (LOD) &lt; 10 ng mL<small>⁻¹</small>, which is within the range of concentration needed to monitor oral health. By comparison, conventional colorimetric LFAs achieve an LOD ≈ 100 ng mL<small>⁻¹</small>, generating a lower diagnostic sensitivity. To achieve this enhanced sensitivity, we optimized the materials used in the SERS–LFA, investigating nanostars (NS) differing in size and material composition and comparing them to commercial gold nanoparticles, as a benchmark. We found that large (56 nm) NSs with a silver coating were the most sensitive nanomaterials for SERS–LFA. To prove the applicability of this SERS–LFA to point-of-care (POC) settings, we tested the optimized LFA with a portable Raman system prototype designed to work on LFAs with 3D-printed cartridges and a line-shaped laser illumination. Using this prototype, we achieved the same LOD observed with the traditional benchtop Raman system. The use of a portable Raman system has brought the SERS–LFA technology closer to the POC use.</p>","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/sd/d4sd00056k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The integrated on-chip isolation and detection of circulating tumour cells","authors":"Sophia Marie Abusamra, Robert Barber, Mohamed Sharafeldin, Claire M. Edwards, Jason J Davis","doi":"10.1039/d3sd00302g","DOIUrl":"https://doi.org/10.1039/d3sd00302g","url":null,"abstract":"Circulating tumour cells (CTCs) are cancer cells shed from a primary tumour which intravasate into the blood stream and have the potential to extravasate into distant tissues, seeding metastatic lesions. As such, they can offer important insight into cancer progression with their presence generally associated with a poor prognosis. The detection and enumeration of CTCs is, therefore, critical to guiding clinical decisions during treatment and providing information on disease state. CTC isolation has been investigated using a plethora of methodologies, of which immunomagnetic capture and microfluidic size-based filtration are the most impactful to date. However, the isolation and detection of CTCs from whole blood comes with many technical barriers, such as those presented by the phenotypic heterogeneity of cell surface markers, morphological similarity to healthy blood cells, and their low relative abundance (~1 CTC/1 billion blood cells). At present, the majority of reported methods dissociate CTC isolation from detection, a workflow which undoubtedly contributes to loss from an already sparse population. This review focuses on developments wherein isolation and detection have been integrated into a single-step, microfluidic configuration, reducing CTC loss, increasing throughput, and enabling an on-chip CTC analysis with minimal operator intervention. Particular attention is given to immune-affinity, microfluidic CTC isolation, coupled to optical, physical, and electrochemical CTC detection (quantitative or otherwise).","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140316034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactivity-based amino-1,8-naphthalimide fluorescent chemosensors for the detection and monitoring of phosgene","authors":"Mannanthara Kunhumon Noushija, Alenthwar Vamshi Krishna, Thorfinnur Gunnlaugsson and Sankarasekaran Shanmugaraju","doi":"10.1039/D4SD00048J","DOIUrl":"10.1039/D4SD00048J","url":null,"abstract":"<p >Phosgene (carbonyl dichloride, COCl<small>₂</small>) is an extremely toxic and hazardous chemical warfare agent (CWA; schedule 3 substance) that poses significant threats to public safety and human well-being. Simultaneously, it is a commonly employed reagent in chemical synthesis in laboratories and industrial settings. Therefore, monitoring phosgene concentration levels is essential for handling them within the workplace and for safeguarding public security. Activity-based fluorescent probes are the most effective real-time detection methods currently used for the detection of CWAs. Reaction-based sensing offers excellent temporal and spatial resolution, minimal side effects, and quick response times. Recently, a plethora of reaction-based fluorescent probes have been designed for the detection of phosgene. This review provides an overview of the latest developments using amino-1,8-naphthalimide-based small-molecule fluorescent probes designed for phosgene detection/sensing. Additionally, we investigate the existing challenges and prospects in the field of reaction-based fluorescent probes for phosgene detection. Herein, various fluorescence sensors are categorized based on their reactions with phosgene, and each section highlights the reaction sites, sensing mechanisms, structure–function relationships, photophysical performances, and practical applications of these sensors. It is our aspiration that this review will provide valuable insights into the advancement of cutting-edge fluorescent probes tailored for phosgene detection and sensing.</p>","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/sd/d4sd00048j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140300783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Impact of Analyte Size on SERS Enhancement Location, Enhancement Factor, Excitation Wavelength, and Spectrum","authors":"Yanjun Yang, Xinyi Chen, Bin Ai, Yiping Zhao","doi":"10.1039/d4sd00014e","DOIUrl":"https://doi.org/10.1039/d4sd00014e","url":null,"abstract":"The study systematically explores the connection between analyte particle size and the hot-spot in Au nanoparticle (NP) dimer systems. Contrary to the conventional understanding tied to localized surface plasmon resonance (LSPR), we show that depending on the analyte particle’s size, the location to produce surface-enhanced Raman scattering (SERS), defined as effective hot-spot, is different from the gap based hot-spot, where the electric field reaches maximum intensity, and the corresponding resonant wavelength is also shifted significantly from LSPR wavelength. This effective hot-spot occurs primarily at the point where the Au NP contacts the analyte particle, covering a larger area than the traditional hotspot and having a significantly smaller enhancement factor. Moreover, different effective hot-spots can be activated under various polarizations. The local electric field versus distance relationship decays significantly slower, complicating the interpretation of SERS spectra of large analyte particles. This complexity offers tunability, allowing for a more precise representation of unique molecular features of the analyte. Consequently, our findings demonstrate the necessity for SERS substrate design rules to be contingent on analyte particle size. Although interpreting SERS spectra is intricate, it can be refined to effectively capture distinctive molecular characteristics. These insights pave a new way to tailor SERS substrate design specifically catering to large analyte particles.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140198780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An approach to use machine learning to optimize paper immunoassays for SARS-CoV-2 IgG and IgM antibodies","authors":"Josselyn Mata Calidonio, Kimberly Hamad-Schifferli","doi":"10.1039/d3sd00327b","DOIUrl":"https://doi.org/10.1039/d3sd00327b","url":null,"abstract":"We developed a COVID-19 paper immunoassay that can detect IgG and IgM antibodies for both SARS CoV-2 spike and nucleocapsid proteins. The test is a multicolor assay that uses as the label gold nanoparticles of different shapes (spheres vs. stars), which result in visually distinct colors of red and blue at the test areas. The assay uses spike and nucleocapsid pro-teins immobilized on nitrocellulose strip at different locations, and the nanoparticle-antibody conjugates run are red nanopar-ticles conjugated to anti-IgG, and blue nanostars conjugated to anti-IgM. Spatial location of signal indicates whether the antibody present is anti-spike or an anti-nucleocapsid, and test area color indicates which antibody type (IgG vs. IgM). Line-ar discriminant analysis (LDA) and machine learning (ML) were used to evaluate the test accuracy, and then used iteratively to modify the assay running conditions (present of quencher molecules, nanoparticle types, washes,) until the test accuracy reached 100 %. The resulting assay could distinguish between 9 different antibody profiles indicative of different disease cases (prior infection vs. vaccinated, early/mid/late stage post infection). Results show that expanding test beyond a specific sensing to selective sensing as an array can enable rapid immunoassays to obtain more complex information, and supervised learning can accelerate test development.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140155193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integration of Melt Electrowritten Microfibers with Magnetoelastic Sensors for Continuous Monitoring of Cell Growth","authors":"Will Skinner, Paula G Saiz, Ander Reizabal, Jeff Plumley, Paul Dalton, Keat Ghee Ong","doi":"10.1039/d4sd00039k","DOIUrl":"https://doi.org/10.1039/d4sd00039k","url":null,"abstract":"Magnetoelastic sensors, which are wirelessly activated and interrogated via magnetic fields, have gained popularity for monitoring physical parameters such as mass loading and stress. The functionalization of the sensor surface has facilitated the development of biosensing devices with the capacity to monitor chemical/biological quantities such as liquid pH, bacteria, and cells growth in biological environments. In this study, melt Electrowriting (MEW) is used for the first time to integrate user-defined microstructures onto the surface of magnetoelastic sensors, aiming to enhance their cell growth monitoring performance. Specifically, MEW is used to define specific topographies on the sensor surface, which enable custom control of attachment, distribution, and alignment of cells along the sensor surface. This technique holds potential for engineering tissues with predefined physical structures, as well as for the development of advanced monitoring systems for tracking the growth of adherent cells in real-time.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140106854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Portable microfluidic immunoassay platform for the detection of inflammatory protein biomarkers","authors":"Gihoon Choi, Betty B. Mangadu, Yooli K. Light, Robert J. Meagher","doi":"10.1039/d3sd00258f","DOIUrl":"https://doi.org/10.1039/d3sd00258f","url":null,"abstract":"Cytokines and acute-phase proteins are promising biomarkers for inflammatory disease. Despite its potential, early diagnosis based on these biomarkers remains challenging without technology enabling highly sensitive protein detection immediately after sample collection, because of the low abundance and short half-life of these proteins in bodily fluids. Enzyme-linked immunosorbent assay (ELISA) is a gold-standard method for such protein analysis, but it often requires labor-intensive and time-consuming sample handling and as well as a bulky benchtop platereader, limiting its utility in the clinical site. We developed a portable microfluidic immunoassay device capable of sensitive, quantitative, and high-throughput protein detection at point-of-need. The portable microfluidic system performs eight magnetic bead-based sandwich immunoassays from raw samples in 40 min. An innovative bead actuation strategy was incorporated into the system to automate multiple sample handling steps with minimal user intervention. The device enables quantitative protein analysis with picomolar sensitivity, as demonstrated using human samples spiked with interleukin-6 and C-reactive protein. The affinity-based assays are highly specific to the target without cross-reactivity. Therefore, we envision the reported device offering ultrasensitive and field-deployable immunoassay tests for timely and accurate clinical diagnosis.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140074139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"pH-responsive i-motif-conjugated nanoparticles for MRI analysis","authors":"Kristine Y Ma, Mireia Perera Gonzalez, Nicole I Langlois, Owen Alzubi, Joseph D. Guimond, Chris Flask, Heather A Clark","doi":"10.1039/d3sd00285c","DOIUrl":"https://doi.org/10.1039/d3sd00285c","url":null,"abstract":"Gadolinium (Gd)-based contrast agents (CA) are widely used to enhance anatomical details in magnetic resonance imaging (MRI). Significant research has expanded the field of CAs into bioresponsive CAs by modulating the signal to image and monitor biochemical processes, such as pH. In this work, we introduce the modular, dynamic actuation mechanism of DNA-based nanostructures as a new way to modulate the MRI signal based on rotational correlation time, τR. We combined a pH-responsive oligonucleotide (i-motif) and a clinical standard CA (Gd-DOTA), to develop a pH-responsive MRI CA. The i-motif folds into a quadruplex in acidic conditions and was incorporated onto gold nanoparticles (iM-GNP) to achieve increased relaxivity, r1, compared to unbound i-motif. In vitro, iM-GNP resulted in a significant increase in r1 over a decreasing pH range (7.5 - 4.5) with a calculated pKa = 5.88 ± 0.01 and a 16.7% change per 0.1 pH unit. In comparison, a control CA with a non-responsive DNA strand (T33-GNP) did not show a significant change in r1 over the same pH range. The iM-GNP were further evaluated in 20% human serum and demonstrated a 28.14 ± 11.2 % increase in signal form neutral pH to acidic pH. This approach paves a path for novel programmable, dynamic DNA-based complexes for τR-modulated bioresponsive MRI CAs.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140045953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anthracene-(aminomethyl)phenylboronic acid ester-immobilized glass substrate as fluorescent sensing materials based on photo-induced electron transfer for detection and visualization of water","authors":"Kazuki Tao, Keiichi Imato, Yousuke Ooyama","doi":"10.1039/d3sd00264k","DOIUrl":"https://doi.org/10.1039/d3sd00264k","url":null,"abstract":"As a reversible and reusable fluorescent material possessing excellent durability for detecting and visualizing moisture and water droplets, we have designed and synthesized a PET (photo-induced electron transfer)-type fluorescent monomer <strong>KT-2</strong> composed of anthracene fluorophore-(aminomethyl)-4-cyanophenylboronic acid pinacol ester (AminoMeCNPhenylBPin) with 3-(triethoxysilyl)propyl group on the Amino moiety and achieved preparation of the drop-casted <strong>poly(KT-2-<em>co</em>-TEOS</strong> or <strong>GPTMS)</strong>silsesquioxane (<strong>SQ</strong>) films on glass substrate via the sol−gel reaction of <strong>KT-2</strong> and tetraethoxysilane (TEOS) or (3-glycidyloxypropyl)trimethoxysilane (GPTMS). <strong>KT-2</strong> exhibited enhancement of the fluorescence emission with the increase in water content in various solvents (less polar, polar, protic, and aprotic solvents) due to the formation of the PET inactive (fluorescent) species <strong>KT-2W</strong> by the interaction with water molecules. The detection limit (DL) of <strong>KT-2</strong> for water in the low water content region below 1.0 wt% in the solvents was 0.015−0.020 wt%, indicating that <strong>KT-2</strong> can act as a PET-type fluorescent sensor for a trace amount of water in solvents. Indeed, it was found that the <strong>poly(KT-2-<em>co</em>-TEOS</strong> or <strong>GPTMS)SQ</strong> films exhibited a reversible fluorescence off–on switching between the PET active state under a drying process and the PET inactive state under a wet process. Actually, the <strong>poly(KT-2-<em>co</em>-TEOS</strong> or <strong>GPTMS)SQ</strong> films initially exhibited a feeble blue emission under a drying process but visually apparent blue emission upon exposure to moisture (under a wet process). In particular, the <strong>poly(KT-2-<em>co</em>-TEOS)SQ</strong> film displays superior reversible switching performance with a huge change in the fluorescent intensity in the dry–wet process compared with the <strong>poly(KT-2-<em>co</em>-GPTMS)SQ</strong> film. This result is attributed to the fact based on the measurements of water contact angles and the roughness on the film surfaces that the <strong>poly(KT-2-<em>co</em>-TEOS)SQ</strong> film with a pitted uneven structure has large amount of <strong>KT-2</strong> units on the surface which make it possible to form the PET inactive <strong>KT-2W</strong> structure by the interaction with water molecule. Herein we propose that PET-type fluorescent sensor-immobilized glass substrates are one of the most promising and convenient functional dye materials based on a fluorescence off–on switching system for detecting and visualizing moisture and water droplets.","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140046083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}