Multi-Functional Nano-Doped Hollow Fiber from Microfluidics for Sensors and Micromotors.

Nano-doped hollow fiber is currently receiving extensive attention due to its multifunctionality and booming development. However, the microfluidic fabrication of nano-doped hollow fiber in a simple, smooth, stable, continuous, well-controlled manner without system blockage remains challenging. In this study, we employ a microfluidic method to fabricate nano-doped hollow fiber, which not only makes the preparation process continuous, controllable, and efficient, but also improves the dispersion uniformity of nanoparticles. Hydrogel hollow fiber doped with carbon nanotubes is fabricated and exhibits superior electrical conductivity (15.8 S m-1), strong flexibility (342.9%), and versatility as wearable sensors for monitoring human motions and collecting physiological electrical signals. Furthermore, we incorporate iron tetroxide nanoparticles into fibers to create magnetic-driven micromotors, which provide trajectory-controlled motion and the ability to move through narrow channels due to their small size. In addition, manganese dioxide nanoparticles are embedded into the fiber walls to create self-propelled micromotors. When placed in a hydrogen peroxide environment, the micromotors can reach a top speed of 615 µm s-1 and navigate hard-to-reach areas. Our nano-doped hollow fiber offers a broad range of applications in wearable electronics and self-propelled machines and creates promising opportunities for sensors and actuators.

Afterglow Nanoprobe-Enabled Quantitative Lateral Flow Immunoassay by a Palm-Size Device for Household Healthcare.

Lateral flow immunoassay (LFIA), a classical point-of-care testing (POCT) technique, plays an important role in disease screening and healthcare monitoring. However, traditional LFIA is either designed for qualitative analysis or requires expensive equipment for quantification, limiting its use in household diagnosis. In this study, we proposed a new generation of LFIA for household health monitoring by using ultralong organic phosphorescence (UOP) nanomaterials as afterglow nanoprobes with a self-developed palm-size sensing device. The UOP nanoprobes exhibit a phosphorescence signal with a second-level lifetime, which completely avoids the interference from excitation light and biological background fluorescence. Therefore, an ultraminiaturized and low-cost UOP nanosensor was successfully designed by eliminating the complex optical path and filtering systems. We chose an inflammatory factor, C-reactive protein (CRP), for household POCT validation. The whole analysis was completed within 9 min. A limit of detection (LOD) of 0.54 ng/mL of CRP antigen was achieved with high stability and good specificity, which is comparable to laboratory instruments and fully satisfying the clinical diagnosis requirement.

Multi-modal nanoprobe-enabled biosensing platforms: a critical review.

Nanomaterials show great potential for applications in biosensing due to their unique physical, chemical, and biological properties. However, the single-modal signal sensing mechanism greatly limits the development of single-modal nanoprobes and their related sensors. Multi-modal nanoprobes can realize the output of fluorescence, colorimetric, electrochemical, and magnetic signals through composite nanomaterials, which can effectively compensate for the defects of single-modal nanoprobes. Following the multi-modal nanoprobes, multi-modal biosensors break through the performance limitation of the current single-modal signal and realize multi-modal signal reading. Herein, the current status and classification of multi-modal nanoprobes are provided. Moreover, the multi-modal signal sensing mechanisms and the working principle of multi-modal biosensing platforms are discussed in detail. We also focus on the applications in pharmaceutical detection, food and environmental fields. Finally, we highlight this field's challenges and development prospects to create potential enlightenment.

A Low-cost Creatinine Biosensor by Differential Optical Signal Readout for the Whole Blood Analysis.

This study developed a low-cost paper-based biosensor for point-of-care (POC) detection of blood creatinine by using differential optical signal readout. Dual-channel photochemical paper-based test strips were fabricated with stackable multilayer films containing pre-immobilized enzymes and reagents for the identification and conversion of creatinine and creatine. Enzyme-linked reactions generated hydrogen peroxide (H2O2), which formed a blue oxidized condensate with aniline derivatives. The color depth was quantified via the differential optical signal of the two channels and positively correlated with the concentration of the analyte. This method was first proposed to address the issue of endogenous interferences in the enzymatic assay of creatinine, greatly improving the detection accuracy. The proposed biosensor was calibrated with spiked blood samples, and achieved a wide detection range of 31-1483 µmol/L, showing superior detection performance to general enzymatic methods, especially in the low concentration range. Creatine interference testing demonstrated that the biosensor could resist the interference of ≤ 300 µmol/L endogenous creatine. It is believed that the proposed optical differential biosensor for blood creatinine could enable to pave the way for a daily monitoring system for renal diseases.Clinical Relevance- This stackable multilayer paper-based biosensor provides an enzymatic colorimetric assay of creatinine in whole blood, which can be read out by the differential optical signal to exclude interference from endogenous creatine.

Surface plasmonic biosensors: principles, designs and applications.

Recently, surface plasmon resonance (SPR) biosensors have been widely used in environmental monitoring, food contamination detection and diagnosing medical conditions due to their superior sensitivity, label-free detection and rapid analysis speed. This paper briefly elaborates on the development history of SPR technology and introduces SPR signal sensing principles. A summary of recent applications of SPR sensors in different fields is highlighted, including their figures of merit and limitations. Finally, the personal perspectives and future development trends about sensor preparation and design are discussed in detail, which may be critical for improving the performance of SPR sensors.

Portable dual-channel blood enzyme analyzer for point-of-care liver function detection.

Because the liver is an important metabolic center in the human body, the reliability and timeliness of chronic liver disease diagnosis are particularly important. Alanine aminotransferase and aspartate transaminase are the two most important liver function indicators, and their test results are crucial in the diagnosis of liver diseases. However, the simultaneous detection of these two indicators is currently restricted by the need for expensive equipment and complicated detection processes. This study proposes a portable dual-channel blood enzyme analyzer (BEA) for point-of-care-testing. The device uses photometric reflectance to quantify the enzyme concentration by evaluating the reflected light intensity. The BEA also precisely controls and maintains the temperature at 37 °C ± 0.1 °C in the dual-channel assay. We assessed the responses of this system within a clinically relevant range by testing blood samples from a local hospital. The test verified that BEA for ALT and AST achieved a detection limit of 3.5 U L-1 and 4 U L-1, detection range of 4-350 U L-1 and 4-250 U L-1, coefficients of variation (CV) that were both less than 10%, and a linear correlation coefficient of 0.9827 and 0.9714 compared with a high-precision clinical biochemistry analyzer (Roche Cobas C702), respectively. We realized remote data analysis and storage through connection with smartphones, which can be applied to remote diagnostics and preventative personal disease management. Therefore, BEA has broad application prospects in the future internet of medical things.

HS-GC-IMS Analysis of Volatile Organic Compounds in Different Varieties and Harvesting Times of Rhizoma gastrodiae (Tian Ma) in Yunnan Province.

Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) coupled with principal component analysis (PCA) was used to investigate the differences in volatile organic compounds (VOCs) in four different varieties of Yunnan Huang Tian Ma (containing both winter and spring harvesting times), Yunnan Hong Tian Ma, Yunnan Wu Tian Ma, and Yunnan Lv Tian Ma. The results showed that the flavor substances of different varieties and different harvesting times of Rhizoma gastrodiae were mainly composed of aldehydes, alcohols, ketones, heterocycles, esters, acids, alkenes, hydrocarbons, amines, phenols, ethers, and nitrile. Among them, the contents of the aldehydes, alcohols, ketones, and heterocyclic compounds are significantly higher than those of other substances. The results of cluster analysis and fingerprint similarity analysis based on principal component analysis and Euclidean distance showed that there were some differences between different varieties of Yunnan Rhizoma gastrodiae and different harvesting times. Among them, Yunnan Lv Tian Ma and Wu Tian Ma contained the richest volatile components. Winter may be the best harvesting season for Tian Ma. At the same time, we speculate that the special odor contained in Tian Ma should be related to the aldehydes it is rich in, especially benzene acetaldehyde, Benzaldehyde, Heptanal, Hexanal, Pentanal, and butanal, which are aldehydes that contain a strong and special odor and are formed by the combination of these aldehydes.

Intelligent sensing based on active micro/nanomotors.

In the microscopic world, synthetic micro/nanomotors (MNMs) can convert a variety of energy sources into driving forces to help humans perform a number of complex tasks with greater ease and efficiency. These tiny machines have attracted tremendous attention in the field of drug delivery, minimally invasive surgery, in vivo sampling, and environmental management. By modifying their surface materials and functionalizing them with bioactive agents, these MNMs can also be transformed into dynamic micro/nano-biosensors that can detect biomolecules in real-time with high sensitivity. The extensive range of operations and uses combined with their minuscule size have opened up new avenues for tackling intricate analytical difficulties. Here, in this review, various driving methods are briefly introduced, followed by a focus on intelligent detection techniques based on MNMs. And we discuss the distinctive advantages, current issues, and challenges associated with MNM-based intelligent detection. It is believed that the future advancements of MNMs will greatly impact the diagnosis, treatment, and prevention of diseases.

Preparation and characterization of 3D hydroxyapatite/collagen scaffolds and its application in bone regeneration with bone morphogenetic protein-2.

Desirable bone engineering materials should have a conducive three-dimensional (3D) structure and bioactive mediators for guided bone regeneration. In the present study, hydroxyapatite (HA)/collagen (Col) scaffolds were prepared by an optimized freeze-drying process. The porosity, moisture content, and mechanical properties of the composite have been investigated. The micro-morphology and structure were analyzed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirmed that self-cross-linked HA/Col was evenly distributed and formed a 3D porous scaffold. The physicochemical/mechanical characterization was carried out by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Morphological observation and CCK-8 assay of co-culture cells indicated that HA/Col scaffolds were biocompatible. Then HA/Col scaffolds coupled with recombinant human bone morphogenetic proteins 2 (rhBMP-2) were implanted in the mandibular critical size defect in rats, and histological staining was used to evaluate the bone reconstruction. The result showed that HA/Col coupled with rhBMP-2 could significantly improve the formation of new bone and angiogenesis within the scaffolds as well as the proliferation and differentiation of osteoblasts. Thanks to the encouraging osteogenesis effects, the well-defined 3D scaffolds (HA/Col) cooperating with bioactive agents (rhBMP-2) are expected to be a promising candidate for bone tissue engineering applied to regenerative medicine.

Single-molecule immunoassay technology: Recent advances.

Detecting diseases at the molecular level aids in early diagnosis and treatment. However, traditional immunological detection techniques, such as enzyme-linked immunosorbent assay (ELISA) and chemiluminescence, have detection sensitivities between 10-16 and 10-12 mol/L, which are inadequate for early diagnosis. Single-molecule immunoassays can reach detection sensitivities of 10-18 mol/L and can detect biomarkers that are difficult to measure using conventional detection techniques. It can confine molecules to be detected in a small spatial area and provide absolute counting of the detected signal, offering the advantage of high efficiency and accuracy. Herein, we demonstrate the principles and equipment of two single-molecule immunoassay techniques and discuss their applications. It is shown that the detection sensitivity can be improved by 2-3 orders of magnitude compared to common chemiluminescence or ELISA assays. The microarray-based single-molecule immunoassay technique can test 66 samples in 1 h, which is more efficient than conventional immunological detection techniques. In contrast, microdroplet-based single-molecule immunoassay techniques can generate 107 droplets in 10 min, which is more than 100 times faster than a single droplet generator. By comparing the two single-molecule immunoassay techniques, we highlight our personal perspectives on the current limitations of point-of-care applications and future development trends.

Yak Milk: Nutritional Value, Functional Activity, and Current Applications.

The yak is a special species that inhabits the Qinghai-Tibet Plateau and its surrounding areas. Its unique habitat gives yak milk certain distinct characteristics compared to regular cow milk. Yak milk not only has a high nutritional value but also holds potential benefits for human health. In recent years, there has been increasing research attention on yak milk. Studies have found that the bioactive components in yak milk have various functional properties, including antioxidant, anticancer, antibacterial, blood pressure-lowering, anti-fatigue, and constipation-relieving effects. However, more evidence is needed to confirm these functions in the human body. Therefore, by reviewing the current research status on the nutrition and functionality of yak milk, we aim to reveal its enormous potential as a source of nutritional and functional substances. This article primarily analyzed the nutritional composition of yak milk and the functional effects of its bioactive components, categorically elucidated the mechanisms behind its functional activities, and provided a brief introduction to related yak milk products. Our objective is to deepen people's understanding of yak milk and provide some references for its further development and utilization.

Electrochemical nucleic acid sensors: Competent pathways for mobile molecular diagnostics.

Electrochemical nucleic acid biosensor has demonstrated great promise in clinical diagnostic tests, mainly because of its flexibility, high efficiency, low cost, and easy integration for analytical applications. Numerous nucleic acid hybridization-based strategies have been developed for the design and construction of novel electrochemical biosensors for diagnosing genetic-related diseases. This review describes the advances, challenges, and prospects of electrochemical nucleic acid biosensors for mobile molecular diagnosis. Specifically, the basic principles, sensing elements, applications in diagnosis of cancer and infectious diseases, integration with microfluidic technology and commercialization are mainly included in this review, aiming to provide new insights and directions for the future development of electrochemical nucleic acid biosensors.

The Potential of Natural Oils to Improve Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory disorder that includes ulcerative colitis (UC) and Crohn's disease (CD), the exact cause of which is still unknown. Numerous studies have confirmed that diet is one of the major environmental factors associated with IBD, as it can regulate the gut microbiota and reduce inflammation and oxidative stress. Since the consumption of oil is essential in the diet, improving IBD through oil has potential. In this article, we first briefly reviewed the current treatment methods for IBD and introduce the role of natural oils in improving inflammatory diseases. We then focused on the recent discovery of the role of natural oils in the prevention and treatment of IBD and summarized their main mechanisms of action. The results showed that the anti-inflammatory activity of oils derived from different plants and animals has been validated in various experimental animal models. These oils are capable of improving the intestinal homeostasis in IBD animal models through multiple mechanisms, including modulation of the gut microbiota, protection of the intestinal barrier, reduction in colonic inflammation, improvement in oxidative stress levels in the intestine, and regulation of immune homeostasis. Therefore, dietary or topical use of natural oils may have potential therapeutic effects on IBD. However, currently, only a few clinical trials support the aforementioned conclusions. This review emphasized the positive effects of natural oils on IBD and encouraged more clinical trials to provide more reliable evidence on the improvement of human IBD by natural oils as functional substances.

Magnetic nanoprobe-enabled lateral flow assays: recent advances.

In recent years, magnetic nanoparticle sensor technologies have attracted considerable interest in the point-of-care-testing (POCT) field, especially in lateral flow immunoassays (LFIAs). Although the visual signal of magnetic nanoparticles is reduced during an inspection, it can be compensated for by magnetic induction, and detection results can be quantified by magnetic sensors. Sensors that use magnetic nanoparticles (MNPs) as markers can overcome the high background noise of complex samples. In this study, MNP signal detection strategies are described from the perspectives of magnetoresistance, magnetic flux, frequency mixing technology, and magnetic permeability, and the principles and development of each technology are introduced in detail. Typical applications of magnetic nanoparticle sensor technologies are introduced. By describing the advantages and limitations of different sensing strategies, we highlight the development and improvement directions of different sensing strategies. In general, the future development of magnetic nanoparticle sensor technologies will be toward intelligent, convenient, and mobile high-performance detection equipment.

A Non-Newtonian liquid metal enabled enhanced electrography.

Biopotential signals, like electrocardiography (ECG), electromyography (EMG), and electroencephalography (EEG), can help diagnose cardiological, musculoskeletal and neurological disorders. Dry silver/silver chloride (Ag/AgCl) electrodes are commonly used to obtain these signals. While a conductive hydrogel can be added to Ag/AgCl electrodes to improve the contact and adhesion between the electrode and the skin, dry electrodes are prone to movement. Considering that the conductive hydrogel dries over time, the use of these electrodes often creates an imbalanced skin-electrode impedance and a number of sensing issues in the front-end analogue circuit. This issue can be extended to several other electrode types that are commonly in use, in particular, for applications with a need for long-term wearable monitoring such as ambulatory epilepsy monitoring. Liquid metal alloys, such as eutectic gallium indium (EGaIn), can address key critical requirements around consistency and reliability but present challenges on low viscosity and the risk of leakage. To solve these problems, here, we demonstrate the use of a non-eutectic Ga-In alloy as a shear-thinning non-Newtonian fluid to offer superior performance to commercial hydrogel electrodes, dry electrodes, and conventional liquid metals for electrography measurements. This material has high viscosity when still and can flow like a liquid metal when sheared, preventing leakage while allowing the effective fabrication of electrodes. Moreover, the Ga-In alloy not only has good biocompatibility but also offers an outstanding skin-electrode interface, allowing for the long-term acquisition of high-quality biosignals. The presented Ga-In alloy is a superior alternative to conventional electrode materials for real-world electrography or bioimpedance measurement.

A smartphone-connected point-of-care photochemical biosensor for the determination of whole blood creatinine by differential optical signal readout.

The level of creatinine in the human body has clinical implications with regard to a potential association with kidney, muscle, and thyroid dysfunction, hence necessitating fast and accurate detection, especially at the point-of-care (POC) level. This paper presents the design, fabrication, and feasibility of a compact, low-cost and reliable POC photochemical biosensor connected to a smartphone for the determination of whole blood creatinine by differential optical signal readout. Disposable, dual-channel paper-based test strips were fabricated using stackable multilayer films pre-immobilized with enzymes and reagents for the identification and conversion of creatinine and creatine, resulting in dramatic colorimetric signals. A handheld optical reader was integrated with dual-channel differential optical readout to address endogenous interferences in the enzymatic assay of creatinine. We demonstrated this differential concept with spiked blood samples, obtaining a wide detection range of 20-1483 µmol/L and a low detection limit of 0.03 µmol/L. Further interference experiments displayed the differential measuring system's excellent performance against endogenous interference. Furthermore, the sensor's high reliability was confirmed through comparison with the laboratory method, with the results of 43 clinical tests consistent with the bulky automatic biochemical analyzer, with its correlation coefficient R2 = 0.9782. Additionally, the designed optical reader is Bluetooth-enabled and can connect to a cloud-based smartphone to transmit test data, enabling active health management or remote monitoring. We believe the biosensor has the potential to be an alternative to the current creatinine analysis conducted in hospitals and clinical laboratories, and it has promising prospects for contributing to the development of POC devices.

Objectification of Tongue Diagnosis in Traditional Medicine, Data Analysis, and Study Application.

Tongue diagnosis is an essential technique of traditional Chinese medicine (TCM) diagnosis, and the need for objectifying tongue images through image processing technology is growing. The present study provides an overview of the progress made in tongue objectification over the past decade and compares segmentation models. Various deep learning models are constructed to verify and compare algorithms using real tongue image sets. The strengths and weaknesses of each model are analyzed. The findings indicate that the U-Net algorithm outperforms other models regarding precision accuracy (PA), recall, and mean intersection over union (MIoU) metrics. However, despite the significant progress in tongue image acquisition and processing, a uniform standard for objectifying tongue diagnosis has yet to be established. To facilitate the widespread application of tongue images captured using mobile devices in tongue diagnosis objectification, further research could address the challenges posed by tongue images captured in complex environments.

Taurine: A Source and Application for the Relief of Visual Fatigue.

According to reports, supplementation with appropriate doses of taurine may help to reduce visual fatigue. Presently, some progress has been made in research related to taurine in eye health, but the lack of systematic summaries has led to the neglect of its application in the relief of visual fatigue. This paper, therefore, provides a systematic review of the sources of taurine, including the endogenous metabolic and exogenous dietary pathways, as well as a detailed review of the distribution and production of exogenous taurine. The physiological mechanisms underlying the production of visual fatigue are summarized and the research progress of taurine in relieving visual fatigue is reviewed, including the safety of consumption and the mechanism of action in relieving visual fatigue, in order to provide some reference basis and inspiration for the development and application of taurine in functional foods for relieving visual fatigue.

Minimally invasive electrochemical continuous glucose monitoring sensors: Recent progress and perspective.

Diabetes and its complications are seriously threatening the health and well-being of hundreds of millions of people. Glucose levels are essential indicators of the health conditions of diabetics. Over the past decade, concerted efforts in various fields have led to significant advances in glucose monitoring technology. In particular, the rapid development of continuous glucose monitoring (CGM) based on electrochemical sensing principles has great potential to overcome the limitations of self-monitoring blood glucose (SMBG) in continuously tracking glucose trends, evaluating diabetes treatment options, and improving the quality of life of diabetics. However, the applications of minimally invasive electrochemical CGM sensors are still limited owing to the following aspects: i) invasiveness, ii) short lifespan, iii) biocompatibility, and iv) calibration and prediction. In recent years, the performance of minimally invasive electrochemical CGM systems (CGMSs) has been significantly improved owing to breakthrough developments in new materials and key technologies. In this review, we summarize the history of commercial CGMSs, the development of sensing principles, and the research progress of minimally invasive electrochemical CGM sensors in reducing the invasiveness of implanted probes, maintaining enzyme activity, and improving the biocompatibility of the sensor interface. In addition, this review also introduces calibration algorithms and prediction algorithms applied to CGMSs and describes the application of machine learning algorithms for glucose prediction.

DropLab: an automated magnetic digital microfluidic platform for sample-to-answer point-of-care testing-development and application to quantitative immunodiagnostics.

In point-of-care testing (POCT), tests are performed near patients and results are given rapidly for timely clinical decisions. Immunodiagnostic assays are one of the most important analyses for detecting and quantifying protein-based biomarkers. However, existing POCT immunodiagnostics mainly rely on the lateral flow assay (LFA), which has limited sensitivity or quantification capability. Although other immunodiagnostic assays, such as enzyme-linked immunosorbent assays (ELISAs), offer more sensitive and quantitative results, they require complex liquid manipulations that are difficult to implement in POCT settings by conventional means. Here, we show the development of DropLab, an automated sample-in-answer-out POCT immunodiagnostic platform based on magnetic digital microfluidic (MDM) technology. DropLab performs microbead-based ELISA in droplets to offer more sensitive and quantitative testing results. The intricate liquid manipulations required for ELISA are accomplished by controlling droplets with magnetic microbeads using MDM technology, which enables us to achieve full automation and easy operations with DropLab. Four ELISAs (the sample in triplicates and a negative control) can be run in parallel on the thermoformed disposable chip, which greatly improves the throughput and accuracy compared to those of other POCT immunodiagnostic devices. DropLab was validated by measuring two protein targets and one antibody target. The testing results showed that the limit of detection (LOD) of DropLab matched that of the conventional ELISA in a microwell plate. DropLab brings MDM one step closer to being a viable medical technology that is ready for real-world POCT applications.