Sensors & diagnostics最新文献

An electrochemical immunoassay for interleukin-6 (IL-6) was developed based on IL-6 capture using magnetic beads and electrochemical signal production using horseradish peroxidase/tetramethylbenzidine. We achieved IL-6 detection from the 50–1000 pg mL⁻¹ range, which is a physiologically relevant IL-6 range for a variety of biological systems. The sandwich assay performed well in phosphate buffered solution as well as in cellular media and human plasma spiked with IL-6, and decreased time to IL-6 concentration readout to approximately one hour. There is also future potential to apply this assay to real-time point-of-care human disease diagnostics.

Contamination of heavy metals in the environment is a burning and contemporary issue of modern life. Whilst lead contamination is historic, the ongoing extensive use of lead in batteries is likely to continue to cause serious environmental problems. Silver ions also present multiple environmental issues, such as bioaccumulation and toxicity. As a result, these two heavy metal ions have a high impact from an environmental and industrial point of view. Thus, the colorimetric and fluorescence detection of these two metal ions has been the subject of intense research during the last decade and pyrene-based fluorophores have played a crucial role in their detection. This review article summarizes the recent chronological progress on pyrene moiety integrated small molecule chemosensors for the colorimetric and fluorescent detection of silver and lead ions. Herein, the different strategies that have been utilized for the recognition of lead and silver ions are discussed. Throughout, the juxtaposition of structural aspects of the chemosensors and their sensitivity has been scrutinized together with an overview and future vision.

Among the currently developed analytical tools, sensors based on fluorescence detection have received immense recognition owing to their high sensitivity, low cost, fast response, and simplicity. The design and synthesis of fluorescence chemosensors to sense metals that are of environmental and biological relevance are of appreciable interest. The efficacy of fluorescent sensors relies on two crucial features: a metal binding unit and a fluorophore that can absorb and emit light. The electronic structure of the sensor is altered upon complexation, leading to a change in light emission or absorption intensity and wavelength. Hydroxypyridinones, a class of N-heterocyclic metal chelators, are appreciated as magnificent chemical tools in metal chelation with a higher affinity towards hard metals, displaying various medical, biological, and industrial applications. However, such compounds are scarcely used as sensors. This article outlines the recent invention of fluorescence chemosensors related to hydroxypyridinone based chelators for the selective sensing of analytes of biological and environmental importance. This discussion involves the structural parameters, coordination mode, and other approaches that helped develop highly selective fluorescence sensors for the ions. In addition, the luminescence properties of the hydroxypyridinones in the energy transfer process of lanthanide chelates as sensitizers are determined.

An imidazo[1,2-a]pyridine-functionalized xanthene dye (Rh-Ip) was designed and developed as a fluorescent probe (Rh-Ip-Hy) for Hg²⁺ by introducing spirolactam to the molecule. The probe Rh-Ip-Hy with a ring-closed spirolactam structure reacts with Hg²⁺ to form a fluorescent ring-opened spirolactone structure. Due to its asymmetric structure and the presence of a Lewis base site, the probe exhibits a larger Stokes shift and higher pH tolerance than the traditional xanthene dyes and probes. Furthermore, the probe is highly selective to Hg²⁺ within a wide pH range of 5.0–11.0. The probe Rh-Ip-Hy also exhibits low cytotoxicity and can be used for the detection of Hg²⁺ in living HeLa cells through fluorescence imaging. Finally, a paper-based test strip was prepared and successfully applied for the detection of Hg²⁺ in tap water and lake water samples.

Visualizing liposome release profiles in small animals is important for evaluating the pharmacokinetic influence of vesicles. Encapsulating near-infrared (NIR) fluorescent dyes to visualize and report liposomal cargo release in vivo, which necessitates high encapsulation with deep self-quenching, is highly desirable in advanced (such as targeting or trigger-release) liposome development. However, passive loading of NIR dyes usually yields low encapsulation efficiencies (1–5%), causing significant wastage and cost-ineffectiveness while using expensive NIR fluorescent dyes. It would be highly beneficial if an active loading method, which typically has an encapsulation efficiency of nearly 100%, is developed. This research describes an active loading approach for two cyanine 5.5 (Cy5.5) derivatives. We discovered that using ammonium sucrose octasulfate (ASO) as a trapping agent allows for nearly 100% encapsulation for both Cy5.5 dyes, accompanied by the formation of nanoprecipitates inside the liposome, as evidenced by cryogenic electron microscopy. Fluorescence spectroscopy confirmed deep fluorescence self-quenching after active loading and a 60–100-fold fluorescence enhancement upon full content release via liposome rupture. Cellular uptake experiments showed that the fluorescence of Cy5.5-loaded liposomes recovered and plateaued after 9 hours of incubation with cells. In vivo fluorescence imaging (IVIS) demonstrated the same fluorescence activation in tumor-bearing mice intratumorally injected with the liposome. We believe that the developed active loading method will enable Cy5.5-loaded liposomes to be a deep tissue-compatible and cost-effective NIR fluorescence release-reporting platform.

Acute myocardial infarction (AMI) is a leading global cause of death. Diagnosis is challenging as cardiac biomarkers are only detectable for a few hours after AMI onset, and current methods are time-consuming and lack selectivity. Therefore, multiple immunological test systems have great importance for rapid and accurate diagnosis. In this context, we developed a rapid immunodiagnostic sensor platform for simultaneous electrochemical detection of cardiac troponin T (cTnT), troponin I (cTnI), and C-reactive protein (CRP) using nanostructured gold-modified laser-scribed graphene (LSG). Aptamer sensors were integrated into the LSG platform for selective AMI biomarkers sensing. Clinical validation was performed on biomarkers from blood samples of 51 AMI patients and 9 healthy controls. Limits of detection were 1.65 ng mL⁻¹ cTnT, 2.58 ng mL⁻¹ cTnI, and 1.84 ng mL⁻¹ CRP. The analytical results determined by the developed platform were compared with the routine standard values of the same patients to prove the accuracy of aptasensors. Sensor results agreed well with standard laboratory assays, highlighting the accuracy of the test platform. The cTnT, cTnI and CRP multiplexed sensor platform demonstrates excellent performance for rapid and sensitive AMI screening.

Digital biosensors facilitate real-time, remote, precise disease detection and biochemical analysis. Recent trends in biosensing methods have focused on miniaturization, automation, and multiplexing. The miniaturization of biosensors has led to the development of portable, flexible, and wearable devices that can be used for point-of-care diagnostics and continuous health monitoring. Furthermore, digital automation has enabled the high-throughput screening of samples, reducing the time and cost of analysis, while integrated multiplexing allows for the simultaneous detection of multiple analytes, increasing the efficiency and accuracy of analysis. This article examines recent scientific advances in developing miniaturized biosensing procedures for digital healthcare. Advancements in digital devices have also contributed to the development of integrated biosensing. The use of smartphones, smartwatches, and other digital devices as readout platforms for biosensors has made biosensing more accessible and user-friendly. The development of artificial intelligence and machine learning algorithms has allowed for the interpretation and analysis of complex biosensor data. This review compares biosensing with current state-of-the-art diagnostic technology. After incorporating biosensors with artificial intelligence in an internet of things platform, they will have enormous potential and market value in the future for personalized healthcare. Based on various device performances and impacts, sensing methods, designs, compatibilities, functionalities, technology integrations, and developments are systematically discussed in this article. The primary objective of this review was to present a comprehensive discussion from the point of view of both technological advancements and translational wisdom. It is essential to have intelligent point-of-care devices with digital technologies for real-time healthcare management. The vision of the future healthcare industry encompasses a range of biosensing methods that offer a glimpse into new possibilities for the market.

This paper presents a review of optical sensor systems for wearable applications aiming at the new demands on healthcare motivated not only by the new paradigms in internet of things, but also in photonics development and artificial intelligence algorithms. In this context, the overview of musculoskeletal disorders and the role of wearable sensor systems in such applications are discussed. In addition, there is a comprehensive discussion of the components of wearable sensor systems with the novel developments and approaches in different wearable applications. Thus, the optical fiber sensor developments, approaches and applications are discussed for their use in smart textiles, biosensors and intrusive applications. Moreover, new developments on power supplies are discussed aiming at self-powered sensor systems. Therefore, this review paper can aid in the development of the new generation of wearable sensor systems in healthcare applications using optical fiber sensors and general optical based sensors, which can overcome or mitigate the shortcomings of conventional sensor technologies.

This article reports the methodology and the proof of concept of a blood-based diagnostic strategy for the SARS-CoV-2 infection. The proposed method relies on the non-specific/selective array-based sensing strategy mimicking the human olfactory system using a cucurbit[7]uril macrocycle receptor conjugated with a library of environmentally sensitive fluorophores. The study cohort includes 26 samples, i.e. 12 cases and 14 controls. Statistical analysis methods such as linear discriminant and random forest were able to successfully classify and discriminate the two groups with almost 90% accuracy. This diagnostic result highlights the methodology and confirms the potential of this non-specific/selective sensing approach for non-invasive clinical diagnosis.

A fluorescent pyrazinium-based 1-benzyl-3,5-diphenylpyrazin-1-ium bromide (BPPyz) chemosensor was synthesized and well-characterized. A significant reduction in blue emission of BPPyz was observed in the presence of TNP as compared to other nitroaromatic compounds, indicating high selectivity towards TNP. In the presence of sulfite ions, BPPyz showed fluorescence quenching and rapid naked-eye detection with a significant color change. The sensing mechanism was investigated through UV–visible studies, time-resolved fluorescence results, and density functional theory (DFT) calculations. The quenching constants (K_SV) are 4.12 × 10⁵ M⁻¹ for TNP and 3.8 × 10⁵ M⁻¹ for sulfite with the detection limits of 9.5 nM and 46.17 nM for TNP and sulfite, respectively. The selectivity of BPPyz towards TNP was ascribed to the ground state charge transfer complex (GSC) formation and resonance energy transfer. Sulfite ion detection involved the formation of a GSC through hydrogen bonding with the pyrazinium proton.