Sensors & diagnostics最新文献

Diagnostic tools are fundamental to informed healthcare decisions, but the current state of in vitro diagnostics presents barriers to providing timely access to a wide menu of tests. This paper discusses a method for overcoming these challenges with a novel and miniaturized point-of-care (PoC) solution, the VitalOne. While many PoC solutions have limited test menus tailored for specific scenarios, Vital Bio introduces a comprehensive test menu in a compact PoC format that uses centrifugal microfluidic workflows to deliver quantitative results across three modalities that have traditionally required three separate instruments. VitalOne has combined three modalities into a single instrument: hematology, clinical chemistry, and immunoassay. This breadth of central-lab quality results covers a wide variety of use cases and helps to eliminate the send-out gap that impedes the adoption of PoC technologies. This paper provides a comprehensive and transparent view of both our assay performance data and underlying methods of operation. By comparing the VitalOne system with established benchmarks commercialized devices including Roche cobas® c701, Sysmex 140, Beckman DxH® 500, Beckman AU® 480, and Beckman Access® 2 instrument systems, we demonstrate consistent assay performance, resilience to interference, and performance that is compliant with Clinical Laboratory Improvement Amendments (CLIA) total allowable error standards. Additionally, this article elucidates our system's operational intricacies and showcases performance data from a diverse set of analytes.

Ce³⁺-sensitized Tb³⁺-activated SrF₂ nanophosphors (NPs) were synthesized using the hydrothermal method. Crystallographic characterization using X-ray diffraction confirms the formation of cubic SrF₂ with space group Fmm for all samples. The FESEM image indicates spherical-shaped particles. Surface functionalization renders that the NPs are dispersible in water. The strong green emission of SrF₂:5% Tb³⁺, 5% Ce³⁺ at 541 nm increases by 50-fold than that of SrF₂:5% Tb³⁺. The resonance energy transfer between Ce³⁺ and Tb³⁺via multipolar interactions is observed. The energy transfer efficiency and spectral overlap integral are calculated. The absolute quantum yield of SrF₂:5% Tb³⁺, 5% Ce³⁺ is observed to be ∼12%. The NPs show excellent biocompatibility towards the HeLa cell line with 70% cell viability. Intercellular uptake of the SrF₂:5% Tb³⁺, 5% Ce³⁺ nanophosphor is fair, and its potential for anti-counterfeiting and forensic fingerprint applications is observed.

Herein, we report the development of an immunosensor for the detection of prostate-specific antigen (PSA). The immunosensor platform was based on the immunometric sandwich protocol, using magnetic-silica nanoparticles for capture and pre-concentration of PSA. The preparation and application of the magnetic-silica nanobioconjugates and the use of phenylboronic acid for the immobilization of the capture antibody are the innovative steps of this report. The fluorescent sensing nanobioprobes contained 6% fluorescein in the fluorescein-doped silica nanoparticles. Silica nanoparticles can easily undergo alkaline dissolution for an enhanced fluorescence signal and thus ultrasensitive detection of PSA. The specificity of the immunosensor was achieved by the use of the anti-PSA monoclonal capture antibody (Ab₁) bioconjugated in an oriented manner onto phenylboronic acid functionalized magnetic-silica nanoparticles. Non-specific binding sites were blocked with glucose to yield Fe₃O₄@SiO₂-PBA-Ab₁/glucose. Ab₁ capture magnetic nanoparticles allowed for ease of separation using a magnet. For sensing, the polyclonal anti-PSA antibody (Ab₂) was bioconjugated onto fluorescein-doped silica nanoparticles to form FITC@SiO₂-PBA-Ab₂/glucose. PSA was selectively isolated, enriched and purified from the serum samples using a magnetic nanobioconjugate (Fe₃O₄@SiO₂-PBA-Ab₁/glucose). A sandwich immunoreaction was achieved with FITC@SiO₂-PBA-Ab₂/glucose binding to the captured PSA. The alkali hydrolysis resulted in the disintegration of the nanoparticle thus releasing FITC molecules for fluorescence detection. This resulted in signal amplification. The analytical performance of the proposed immunosensor showed an excellent linear relationship between the fluorescence signal intensity and the concentration of PSA ranging from 2.0 pg mL⁻¹ to 100 ng mL⁻¹. The very low limit of detection (LOD) was 0.81 pg mL⁻¹ and the limit of quantification (LOQ) was 2.46 pg mL⁻¹. The immunosensor also exhibited good specificity and selectivity to PSA with 98.0–102.7% recovery rates. The detection was accomplished in newborn calf serum samples representing real samples.

Theranostics is a field of nuclear medicine which uses the same targeting vector and chelating system for both a diagnostic and therapeutic radionuclide, allowing for uniformity in imaging and treatment. This growing field requires the development of more flexible chelate systems that permit novel targeting strategies. Toward this end, a multimodal architecture has been realized, making use of a phosphazene-based core and click chemistry to achieve a flexible and customizable scaffold. The six arm phosphazene-based core can scaffold six DTPA chelating motifs or a mixed set of 3 : 3 DTPA : DFO chelates resulting in two multimodal compounds, pDbDt and pDbDtDf, respectively. Terbium complexes displayed strong luminescence, supporting that the structures act as an organic antenna for luminescence. Metal displacement titration studies confirmed the desired structures as well as the capability for heterometallic labeling of the structures. These structures were found to have high thermal and biological stability in vitro. Radiolabeling of each compound resulted in high molar activity labeling of each compound: 169 MBq nmol⁻¹: [¹⁶¹Tb]Tb–pDbDt, 170 MBq nmol⁻¹: [⁸⁹Zr]Zr–pDbDtDf, and the mixed radiolabeling illustrated chelation of both radionuclides in a 1 : 1 ratio. This multimodal architecture is promising as a heterometallic structure for coupling of both a diagnostic and a therapeutic radionuclide with a highly customizable core structure.

Electrogenerated chemiluminescence, also called electrochemiluminescence (ECL), has attracted much attention in various fields of analysis due to its high sensitivity, extremely wide and dynamic range and excellent control of space and time of the light emission. The great success of ECL for in vitro detection results from the advantages of combining the selectivity of biological recognition elements and the sensitivity and controllability of ECL technology. ECL is widely applied as a powerful analytical technique for ultrasensitive detection of biomolecules. In this review, we summarize the recent developments and applications of ECL for immunosensing. Herein, we present the sensing schemes and their applications in different areas, such as detection of biomarkers, bead-based detection and bacteria and cell analysis and provide future perspectives on new developments in ECL immunosensing. In particular, ECL-based sensing assays for clinical sample analysis and medical diagnostics and the development of immunosensors for these purposes are highlighted.

The biological taste sensing system has a sensitive perception ability for taste substances (tastants) and is considered as one of the most efficient chemical sensing systems in nature. With the rapid development of human society, biomimetic taste-based biosensors have become increasingly important to improve human life quality and ensure human health, and have been widely applied in many fields such as food safety, biomedicine, and public health. In recent years, researchers have been devoted to developing a new type of chemical sensing system. Among them, biomimetic olfactory-based biosensors have shown promising prospects and potential applications compared to traditional chemical sensors due to the utilization of well-developed natural molecular recognition mechanisms. Biomimetic taste-based biosensors usually employ biologically originated taste cells, taste receptors, taste buds, taste organoids and lipid membranes as sensitive elements, combined with secondary transducers to achieve specific and sensitive detection of tastants in order to obtain comparable detection performance to that of the biological taste system. This review summarizes the most recent advances in biomimetic taste-based biosensors based on biological taste sensing elements. First, the basic principle of biomimetic taste-based biosensors is briefly introduced. Then, the system composition and development of biomimetic taste-based biosensors are outlined and discussed in detail, with a focus on the preparation technology of sensitive elements and their coupling with transducers. In addition, the performance of biomimetic taste-based biosensors and their applications in food quality testing and basic and clinical research are summarized. Finally, the current challenges and development trends of biomimetic taste-based biosensors are proposed and discussed.

Rapid and efficient early-stage tumor detection is crucial in cancer diagnostics. Recent research indicates that microRNA-141 expression levels serve as a predictive biomarker for prostate cancer cell count in the human body. In this study, we developed an original competitive system for miRNA-141 detection using Prussian blue nanoparticles (PBNPs), comparing it with a horseradish peroxidase (HRP)-based competitive system for the same target. The competitive system involved miRNA-141 and biotin-miRNA-141 on a magnetic bead-modified capture probe specific to miRNA-141. The synthesized PBNPs were conjugated to avidin, resulting in the formation of avidin–PBNPs. These conjugates were used as a substitute for streptavidin–HRP. The peroxidase-like activity of PBNPs catalyzed the colorimetric substrate (3,3′,5,5′-tetramethylbenzidine), producing a distinct blue color measured at 630 nm. Under optimal conditions, both PBNPs and HRP-based systems exhibited a linear response to miRNA-141 concentrations (50 pM to 300 pM and 80 pM to 500 pM, respectively). Among the two systems investigated in this study, the PBNPs-based bio-assay demonstrated exceptional sensitivity, achieving a remarkably low LOD of 0.61 pM and an analysis time of 32 minutes. These biosensors successfully determined miRNA-141 levels in spiked human serum.

Visual analysis methods have received widespread attention due to their simplicity, economy, and intuitive results. In this work, a visual DNA quantitative analysis method based on surface selective site-directed crystallization (SSSC) was developed. Firstly, we explored the formation of calcium carbonate crystals with unique polymorphism induced by the surface of functionalized glass slides with different groups; among them, the calcite induced by the –COOH functional group has a uniform shape, larger size, and even distribution, so it serves as a signal promoter. In contrast, due to the –N(CH₃)₃ group acting as a signal inhibitory molecule by inhibiting crystallization, the signal molecule is captured through DNA hybridization, and the crystallization reaction is performed. The calcite growing on the DNA site is visible to the naked eye, and the DNA molecules hybridized on the surface of the glass slide are further quantified. The detection limit of this proposed visual method is 0.1 fM, and only a smartphone is needed to complete basic quantification. This work provides a basis for research into the use of single crystals as digital readouts in the field of DNA analysis, with the advantages of being simple and economical and requiring minimal equipment.

Site-specific protein : DNA conjugation is gaining increasing importance in detection technologies such as quantitative immuno-PCR (qIPCR). Until now, DNA-binding proteins have been a relatively untapped source of protein : DNA conjugation systems. In Escherichia coli, the biotin protein ligase (BirA) is a biotin-dependent DNA-binding protein that offers a means to connect a protein of interest (POI) with DNA. Here, we explored BirA as a unique on–off protein : DNA connection switch for the production of self-assembling POI : DNA conjugates. Green fluorescent protein (GFP) is a versatile protein tag and reporter, commonly quantified by fluorescence detection. However, low GFP concentrations are challenging to detect and require more sensitive methods. A multitude of high-affinity antibodies are available for capture and detection of GFP as an affinity tag. As such, a well-characterised GFP-tagged BirA (BirA-GFP) was selected for the development and validation of an innovative qIPCR platform technology. The unique principle of this assay involves the assembly of two BirA-GFP with the bioO repressor DNA sequence in the presence of ATP and biotin. The resulting high affinity bioO : BirA-GFP complex can be applied in various formats to detect the presence of anti-GFP IgG as well as GFP immobilised on a surface. Complete release of the quantifiable bioO DNA can easily be achieved by omitting ATP and biotin in the final elution step. The new BirA-based qIPCR assay enabled picomolar (≥10⁻¹² M) detection of GFP and anti-GFP IgG as well as their affinity profiling.

A hybrid electrochemical DNA biosensor that integrates various technologies, such as laminar flow, surface hybridization, DNA-microarray, thermo-responsive nanocoating and localized photothermal heating, is presented here. A photothermal module based on gold nanostructures photoactivated by a green-light source (532 nm) was developed for easy temperature management. The hybridization product is electrochemically detected by a three-planar-microelectrode system upon dsDNA denaturation. Performances of the hybrid biosensor were investigated by detection of the cDNA target, resulting in a sensitivity of about 2.62 μA nM⁻¹ cm⁻² and a limit of detection of 1.5 nM, as a function of the capture probe sequence. The findings facilitate the integration of multiple technologies, enabling the development of low-cost and point-of-care detection systems for molecular analysis.