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The demand for high-performance inspection technology for lithium-ion batteries is prominent with its increasingly diversified application scenarios. However, traditional detection techniques based on the external output response cannot accurately reflect the evolutionary trends within the cell, such as structural changes and product distribution. Thus, it's of great necessity to explore accurate and non-destructive testing techniques, among which ultrasonic detection technology evaluating battery interior state through acoustic response has drawn significant attention from researchers. This review focuses on advances in ultrasonic detection techniques for individual pouch-type lithium-ion batteries, including inspection theory and monitoring applications, as well as the current shortcomings and challenges. In general, this technique can be applied to most aspects, including defects, health, state of charge, material properties, and much more. Through an in-depth analysis of ultrasonic detection, all key insights in this review are expected to promote the development of safe lithium-ion batteries and efficient in-situ detection technologies. [ABSTRACT FROM AUTHOR]

Hydrated sulfate deposits have been detected on Mars. A spaceflight instrument capable of detecting microfossils in these salt deposits is highly important for the search for ancient life on Mars. This study employed a range of analytical methods, including nondestructive optical microscopy and SEM-EDX, as well as spatially resolved laser ablation mass spectrometry (LIMS), the latter being designed for in-situ analyses on planetary surfaces, to comprehensively examine the morphology, texture, mineralogy, and geochemistry of fossil-bearing gypsum deposits from Algeria. These extensive gypsum formations formed during the Messinian Salinity Crisis (MSC) and serve as excellent astrobiological analogs for the large-scale hydrated sulfate deposits detected on Mars. Significant research on Messinian gypsum reveals notable microbial fossil filaments. This study aims to determine whether optical microscopy and LIMS measurements together can detect fossil filaments in the gypsum samples, identify their composition, and decipher their biogenicity and syngeneity. Spatially resolved depth profiling and chemical mapping analysis of one representative fossil filament using LIMS provided detailed mineralogical and compositional variations that correlate with distinctive morphological features. These findings collectively indicate that the fossil filament exhibits distinct composition and diagenetic processes in comparison to the surrounding gypsum host. The microfossil’s syngeneity and biogenicity were established based on the presence of morphological biosignatures, biologically relevant elements, and biologically induced or influenced minerals such as dolomite and clay minerals. The formation of these minerals within the physico-chemical context of ancient Martian lakes was also discussed. The same suite of measurements and techniques could be applied to study microfossil-bearing gypsum formations on Mars and beyond.

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pesticides play an important role in conventional agriculture. Yet, their harmful effects on the environment are becoming increasingly apparent. The occurrence of pesticides is hence being monitored worldwide. For fast, easy, yet sensitive identification, surface-enhanced Raman spectroscopy (SERS) is a powerful tool. In this study, a method is introduced that may be amended to in-field detection of pesticides. Gold and silver nanoparticles were synthesized, size-tailored, and characterized. The herbicide paraquat and the fungicide thiram served as model compounds. The preparation yielded reproducible SERS spectra. Using quantum chemical computation, Raman and SERS spectra were calculated and analyzed. The interpretation of vibrational modes in combination with SERS enhancement and attenuation allowed us to identify compound-specific bands. The assignment was interpreted in terms of the orientation of paraquat and thiram on the gold and silver nanoparticle surfaces. Paraquat preferred a co-planar arrangement parallel to the gold nanoparticle surface and a head-on orientation on the silver nanoparticle. For thiram, breaking of the disulfide bond was recognized, such that interaction with the surface occurred via the sulfur atoms. Successful detection of the pesticides after recollection from vegetable leaves demonstrated the method's applicability for pesticide identification. [ABSTRACT FROM AUTHOR]

Dissolved gases in the aquatic environment are critical to understanding the population of aquatic organisms and the ocean. Currently, laser absorption techniques based on membrane separation technology have made great strides in dissolved gas detection. However, the prolonged water–gas separation time of permeable membranes remains a key obstacle to the efficiency of dissolved gas analysis. To mitigate these limitations, we demonstrated direct measurement of dissolved gas using the evanescent-wave absorption spectroscopy of a tapered silica micro-fiber. It enhanced the analysis efficiency of dissolved gases without water–gas separation or sample preparation. The feasibility of this sensor for direct measurement of dissolved gases was verified by taking the detection of dissolved ammonia as an example. With a sensing length of 5 mm and a consumption of ~50 µL, this sensor achieves a system response time of ~11 min and a minimum detection limit (MDL) of 0.015%. Possible strategies are discussed for further performance improvement in in-situ applications requiring fast and highly sensitive dissolved gas sensing. [ABSTRACT FROM AUTHOR]

We present a sensitive and compact quantum cascade laser-based photoacoustic greenhouse gas sensor for the detection of CO2, CH4 and CO and discuss its applicability toward on-line real-time trace greenhouse gas analysis. Differential photoacoustic resonators with different dimensions were used and optimized to balance sensitivity with signal saturation. The effects of ambient parameters, gas flow rate, pressure and humidity on the photoacoustic signal and the spectral cross-interference were investigated. Thanks to the combined operation of in-house designed laser control and lock-in amplifier, the gas detection sensitivities achieved were 5.6 ppb for CH4, 0.8 ppb for CO and 17.2 ppb for CO2, signal averaging time 1 s and an excellent dynamic range beyond 6 orders of magnitude. A continuous outdoor five-day test was performed in an observation station in China’s Qinling National Botanical Garden (E longitude 108°29’, N latitude 33°43’) which demonstrated the stability and reliability of the greenhouse gas sensor.

ABSTRACTWearable sweat sensors are gaining significant attention due to their unparalleled potential for noninvasive health monitoring. Sweat, as a kind of body fluid, contains informative physiological indicators that are related to personalized health status. Advances in wearable sweat sampling and routing technologies, flexible, and stretchable materials, and wireless digital technologies have led to the development of integrated sweat sensors that are comfortable, flexible, light, and intelligent. Herein, we report a flexible and integrated wearable device via incorporating a microfluidic system and a sensing chip with skin-integrated electronic format toward in-situ monitoring of uric acid (UA) in sweat that associates with gout, cardiovascular, and renal diseases. The microfluidic system validly realizes the real-time capture perspiration from human skin. The obtained detection range is 5–200 μM and the detection limit is 1.79 μM, which offers an importance diagnostic method for clinical relevant lab test. The soft and flexible features of the constructed device allows it to be mounted onto nearly anywhere on the body. We tested the sweat UA in diverse subjects and various body locations during exercise, and similar trends were also observed by using a commercial UA assay kit.

The tea plant is a valuable and evergreen crop that is extensively cultivated in China and many other countries. Currently, there is growing research interest in this plant. For the tea industry, it is crucial to develop rapid and non-invasive methods to evaluate tea plants in their natural environment. This article provides a comprehensive overview of non-invasive sensing techniques used for in-situ detection of tea plants. The topics covered include leaf, canopy, and field-level assessments, as well as statistical analysis techniques and characteristics specific to the research. Non-invasive testing technology is primarily used for monitoring and predicting tea pests and diseases, monitoring quality, and nutrients, determining tenderness and grade, identifying tea plant varieties, automatically detecting, and identifying tea buds, monitoring tea plant growth, and extracting tea garden areas through remote sensing. It also helps to evaluate planting suitability, assess disasters, and estimate yields. Additionally, the article examines the challenges and prospects of emerging techniques aimed at resolving the in-situ detection problem for tea plants. It can assist researchers and producers in comprehensively understanding the tea environment, quality characteristics, and growth process, thereby enhancing tea production quality, and fostering tea industry development. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, large numbers of jellyfish have congregated in marine areas, leading to a decline in other plankton and fisheries. Jellyfish themselves have a certain toxicity and aggression, which have a serious impact on the safety of human life. In order to detect the quantity and distribution of underwater jellyfish, and to be more proactive in the prevention and control of Aurelia outbreaks, this study proposed a method for in-situ detection of underwater jellyfish based on the improved Faster R-CNN network model. Firstly, the real data sets of three species of jellyfish in the Qinhuangdao sea area were established by using underwater high-definition camera. The Multi Scale Retinex with Colour Restoration (MSRCR) algorithm was used to improve the brightness and contrast of the underwater images. Secondly, the residual network Resnet50 was integrated into the backbone network for better feature extraction; then the semi-precision floating-point number FP16 was added to improve the training speed. Finally, comparative experiments were conducted to verify the improved network. The F1 value, the P-R curve, the Loss curve and the AP value of the three detection models were evaluated and compared. The experimental results showed that compared to Vgg16 network and YOLO V3 network, the training speed was improved from 1.85bit/s to 7.35bit/s, and the accuracy was also improved to over 0.98. The experimental results were good, and the research results provided a more accurate and faster method for the in-situ detection of underwater jellyfish.

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbendazim (CBZ) residues in food are a severe threat to food safety, and their detection is a challenging problem in food science. We introduce here a new method based on laser desorption postionization mass spectrometry imaging (LDPI-MSI) for detecting CBZ residues in carrots. In the novel LDPI-MSI method, two distinct laser beams simultaneously exert dissociation and ionization, which offers several advantages over traditional techniques based on single-photon matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), including simplified sample preparation, streamlined operation workflow, and a lower limit of detection (LOD). The LOD, in the proposed method, has been lowered to 0.019 ppm. Coupled with mass spectrometry imaging (MSI), the LDPI-MS method enabled in situ detection of small molecular compounds, such as chemical pesticides, and provided comprehensive and accurate results. The image obtained from the characteristic mass spectrometric signature of CBZ at m/z 191 illustrated that most of the CBZ could not enter the carrot tubers directly, but a small amount of CBZ entered the carrot root and was mainly concentrated in the central xylem. The results suggest that the proposed method could potentially be used in pesticide analysis.

A flexible Surface-Enhanced Raman Spectroscopy (SERS) substrate based on silver nanoparticles encapsulated in an agar gel has been probed to detect the fungicide thiabendazole (TBZ) reaching a limit of detection (LOD) of 30 ng/cm2. In addition, a simple and sensitive strategy was employed for in-situ detection of TBZ on fruit and vegetable peels. For that purpose, peels of different fruits and vegetables were intentionally contaminated with different amount of TBZ, and the analyte was subsequently extracted within few seconds by gently rubbing the surface with the SERS substrate. The lowest value of TBZ detected on eggplant and green pepper peels was 50 ng/cm2. The values achieved for apple and pear peels were 0.20 μg/cm2 and 40 ng/cm2, respectively. On the other hand, for tomato and strawberry peels the lowest value achieved was 0.50 μg/cm2. The variation in sensitivity can be attributed to differences in the surface properties of the different peels. The above results show that this flexible SERS substrate can be further employed for the detection of contaminants in practical applications for food safety inspection.

One of the most frequent malignant tumors seen in clinics is primary liver cancer, also referred to as the "king of cancers." Therefore, the necessity for an effective and precise detection technique is urgent. Compared with the cantilever beam, the double-ended clamped beam has the characteristics of higher resonance frequency and stronger noise immunity, so it has a good application prospect as a biosensor. This paper takes the double-ended clamped beam biosensor as the object and focuses on the method that can be applied to the early diagnosis and detection of liver cancer. The manufacturing process of the double-ended clamped beam and the biofunctional modification of the beam surface were introduced. Meantime, this paper introduces the integration of the composite double-ended clamped beam biosensor system. As a result, a high-sensitivity, high-reliability in situ real-time monitoring technology for early-stage liver cancer is proposed. A composite double-ended clamped beam made of silicon and silicon nitride is used. The size of the double-ended clamped beam is 280 µm × 50µm × 5µm. This paper provides a low-cost, portable, and rapid early diagnosis method for liver cancer, which has very significant application value in the field of early cancer screening. [ABSTRACT FROM AUTHOR]

[Display omitted] • The EC-QCL is used for phosphate detection in water bodies for the first time. • The EC-QCL detection system is superior than FTIR-ATR in stability and sensitivity. • The method provides a novel idea for the development of phosphate in-situ detection. Excessive discharges of industrial and domestic sewage containing high concentrations of phosphorus are causing damage to the environment, so the detection of these pollutants in bodies of water is extremely critical. External cavity quantum cascade laser (EC-QCL) spectroscopy is a novel measurement technology that surpasses conventional infrared spectroscopy techniques. In this research, we propose a transmission detection system with a long optical path based on an EC-QCL for the detection of phosphate concentration in water bodies. Linear regression models were established based on this detection system, with all determination coefficients higher than 0.98 and a minimum detection limit smaller than 5.1 ppm. Additionally, the high-power spectral density of the EC-QCL permits the construction of a model using the raw radiation intensity data, as opposed to the conventional technique which depends on a reference background. The results show that the overall performance of the model based on the raw radiation intensity is similar to that of the model based on absorbance data. The EC-QCL detection system proposed in this study can ensure accuracy in the detection of pollutants, and the advantage of miniaturization provides a novel idea for the following development of portable phosphate in-situ sewage detection sensors. [ABSTRACT FROM AUTHOR]

Benzene and toluene, primarily emitted from vehicle exhaust, are common volatile organic compounds (VOCs). These aromatic compounds in the atmosphere undergo further photooxidation to form secondary organic aerosol (SOA), which are a primary factor in haze weather. Aromatic SOA is more difficult to detect by traditional detection methods. Microwave plasma torch (MPT) is an ambient ionization source based on microwave plasma developed in recent years. Herein, a microwave plasma torch desorption ionization high-resolution mass spectrometry (MPT-HRMS) technique was designed for the direct analysis of aromatic SOA in the environment. For environmental haze samples, no pretreatment is required, and over twenty types of aromatic hydrocarbon derivatives or oxidation products can be detected in situ using MPT-HRMS. The possible mechanisms underlying the formation of aromatic SOA were investigated. MPT-HRMS is a powerful technical tool for rapidly tracking non-targeted aromatic SOA and their transformations in the environment. This contributes to an in-depth understanding of the formation mechanisms of SOA and their impact on air pollution. [Display omitted] • In situ detection : utilizing in situ analysis eliminates the need for a pre-processing extraction step. • On-line mass spectrometry detection: high-resolution analysis at the scale of a few milliseconds. • Chemical characterization of haze: tracking aromatic SOA and their transformations. • Explored the possible mechanisms of aromatic SOA: the formation pathways from toluene to oxidation products. • DFT calculations: the mechanism of the reaction was evaluated by Δ G. [ABSTRACT FROM AUTHOR]

Assessing the levels of furfural in insulating oils is a crucial technical method for evaluating the degree of aging and mechanical deterioration of oil-paper insulation. The surface-enhanced Raman spectroscopy (SERS) technique provides an effective method for enhancing the sensitivity of in-situ detection of furfural. In this study, a homogeneous three-dimensional (3D) urchin-like Au@W 18 O 49 heterostructure was synthesized as a SERS substrate using a straightforward hydrothermal method. The origin of the superior Raman enhancement properties of the 3D urchin-like heterostructures formed by the noble metal Au and the plasmonic semiconductor W 18 O 49 , which is rich in oxygen vacancies, is analyzed experimentally in conjunction with density-functional theory (DFT) calculations. The Raman enhancement is further amplified by the remarkable dual localized surface plasmon resonance (LSPR) effect, which generates a strong local electric field and creates numerous "hot spots," in addition to the interfacial charge transport (CT). The synergistic effect of these factors results in the 3D urchin-like Au@W 18 O 49 heterostructure exhibiting exceptionally high SERS activity. Testing the rhodamine 6G (R6G) probe resulted in a Raman enhancement factor of 3.41 × 10−8, and the substrate demonstrated excellent homogeneity and stability. Furthermore, the substrate was effectively utilized to achieve highly sensitive in-situ surface-enhanced Raman scattering (SERS) detection of dissolved furfural in complex plant insulating oils. The development of the 3D urchin-like Au@W 18 O 49 heterostructure and the exploration of its enhancement mechanism provide theoretical insights for the advancement of high-performance SERS substrates. [Display omitted] • 3D urchin-like Au@W 18 O 49 heterostructure as a high-performance SERS substrate. • The SERS substrate exhibits a high SERS enhancement factor, excellent homogeneity and long-term durability. • The substrate can be used for the in-situ detection of furfural in complex insulating oil environments. • Experiments combined with DFT calculations reveal the synergistic enhancement mechanism of dual LSPR and CT. [ABSTRACT FROM AUTHOR]

The Meridian Project's sounding rocket mission uses a mass spectrometer to conduct in-situ atmospheric detection. In order to assess the influence of surface material outgassing and the attitude control jet on the spectrometer's detection, a sounding rocket platform was modeled and simulated. Using the physical field simulation software COMSOL and the Monte Carlo method, this study investigated whether the gas molecules from the two cases could enter the in-situ atmospheric mass spectrometer's sensor sampling port after colliding with the background atmosphere. The simulation results show that the influence of surface material outgassing on the in-situ atmospheric detection is very small, even under the conditions of medium solar activity and medium geomagnetic activity, while the influence of the attitude control jet on the in-situ atmospheric detection is large but can be reduced by reducing the low-altitude attitude control operation and decreasing the transmission probability. Through simulation optimization and according to engineering needs, increasing the nozzle outlet cross-sectional area, increasing the temperature of the gas used for attitude control, increasing the nozzle rotation angle, increasing the nozzle outlet angle, or increasing the nozzle center height can reduce the transmission probability. This model can simulate and analyze the influence of both surface material outgassing and attitude control jets on in-situ atmospheric detection, optimize relevant parameters, and provide new ideas for relevant work. [ABSTRACT FROM AUTHOR]

Most in situ tool wear monitoring methods during micro end milling rely on signals captured from the machining process to evaluate tool wear behavior; accurate positioning in the tool wear region and direct measurement of the level of wear are difficult to achieve. In this paper, an in situ monitoring system based on machine vision is designed and established to monitor tool wear behavior in micro end milling of titanium alloy Ti6Al4V. Meanwhile, types of tool wear zones during micro end milling are discussed and analyzed to obtain indicators for evaluating wear behavior. Aiming to measure such indicators, this study proposes image processing algorithms. Furthermore, the accuracy and reliability of these algorithms are verified by processing the template image of tool wear gathered during the experiment. Finally, a micro end milling experiment is performed with the verified micro end milling tool and the main wear type of the tool is understood via in-situ tool wear detection. Analyzing the measurement results of evaluation indicators of wear behavior shows the relationship between the level of wear and varying cutting time; it also gives the main influencing reasons that cause the change in each wear evaluation indicator. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) play fundamental roles in various biological and chemical processes in nature and industries, including cell signaling, disease development and aging, immune defenses, environmental remediation, pharmaceutical syntheses, metal corrosion, energy production, etc. As such, their detection is of paramount importance, but their accurate identification and quantification are technically challenging due to their transient nature with short lifetimes and low steady-state concentrations. As a highly sensitive and selective analytical technique, surface-enhanced Raman spectroscopy (SERS) is promising for detecting ROS in real-time, enabling in situ monitoring of ROS-involved electrochemical and biochemical events with exceptional resolution. This review provides a comprehensive analysis of the state-of-the-art in the SERS-based detection of ROS. Herein, the principles and ROS sensing mechanisms of SERS have been critically evaluated, highlighting their emerging applications in direct and indirect ROS monitoring in electrochemical and biological systems. The developments and reaction schemes of selective SERS probes for superoxide ( • O 2 - ), hydroxyl radicals ( • OH), nitric oxide ( • NO), peroxynitrite (ONOO - ), and hypochlorite (OCl - ) are presented. Finally, technical challenges and future research directions are discussed to guide the design of SERS for ROS analysis.

Stimuli-responsive hydrogel possesses a strong loading capacity to embed luminescent indicators for constructing food safety sensors, which are suitable for field application. In this work, a fluorescent hydrogel sensor was fabricated by incorporating Ag+-modified carbon dots (CDs-Ag+) into a sodium alginate (SA) hydrogel for in-situ detection of thiram. The fluorescence of CDs was quenched due to the combined effects of electrostatic adsorption and electron transfer between Ag+ and CDs. The formation of an Ag S bond between thiram and Ag+ facilitates the release of CDs, causing subsequently fluorescence recovery. Combined with smartphone and analysis software, the fluorescence color change of the hydrogel sensor was converted into data information for quantitative detection of thiram. Such a sample-to-result step is completed within 10 min. Notably, the in-situ detection experiment of thiram in fruit and vegetable samples confirmed the practical application of the hydrogel sensor. Therefore, the hydrogel sensor provides a new research direction for the in-situ detection of pesticide residues in the monitoring of food safety. [Display omitted] • A kind of CDs-Ag+-based SA hydrogel was constructed to detect thiram, and the detection limit was 5 ng mL−1. • The quenching mechanism of Ag+ to CDs and the response mechanism to thiram were systematically discussed. • SA hydrogel can in-situ detecte thiram. • The SA hydrogel performs good reliability in practical samples such as strawberries. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass-based derivatives coupled with surface-enhanced Raman spectroscopy (SERS) technology have emerged as an appealing and indispensable tool in food safety and environmental monitoring for rapidly detecting trace contaminants like pesticide residues. The membrane material, serving as a substrate, ensures both sampling flexibility and test accuracy by directing the diffusion-adsorption process of the molecules. However, the existing membrane substrates, critical for the practical application of SERS, suffer from issues such as costly, intricate fabrication procedures, or restricted detection capabilities. Herein, we present a flexible, transparent, and biodegradable cellulose acetate membrane with gold nanoparticles (AuNPs) uniformly embedded, fabricated using a simple scraping method. This membrane achieved a limit of detection (LOD) of thiram pesticide in water at 10−8 g mL−1. The unique optical transparency of the substrates allowed for in-situ detection on surfaces, with an LOD of thiram reaching 30 ng cm−2. Furthermore, SERS substrates made from corn stover-derived cellulose acetate enable the detection of various contaminants, highlighting their cost-effectiveness and eco-friendliness because of the abundance and low environmental impact of the raw materials. [Display omitted] • A AuNPs-acetylcellulose membrane was obtained by a facile fabrication procedure. • The membrane could be fabricated using lignocellulosic biomass material corn stover. • The membrane could be used as a sensor for trace contaminants by SERS detection. • Molecules followed pseudo-first-order adsorption kinetics during SERS detection. • The flexible and transparent substrates enabled in-situ detection on surfaces. [ABSTRACT FROM AUTHOR]

This work proposed innovative methods and designed an experimental setup for simplified in-situ melt flowability detection and product quality evaluation in injection molding. [Display omitted] • Simplified approaches for in-situ melt flowability detection and product quality evaluation. • Apparent viscosity simplifying corrections about entrance effect and non-Newtonian behavior for flowability observation. • Equivalent viscosity index without shear rate and stress identifications for flowability determination. • Equivalent weight index extending functionality for product quality detection. • Molten resin flowability mapping with final product quality and guiding production. In-situ methods for monitoring flowability/weight can promote melt/product consistency in continuous production lines. However, traditional rheometers don't fulfill manufacturing environment while the developed real viscosity characterization needs complex corrections, hindering its application in product quality evaluation. It is necessary to establish indexes that can easily reflect online melt/product information in injection molding. This work proposed two simplified methods, apparent and equivalent viscosity indexes, for melt flowability observations. An equivalent weight index was determined for product quality evaluations. Melt filling-related process parameters validated the feasibility of proposed indexes. The results reveal that the apparent viscosity effectively predicts melt flowability variations and is strongly related (>0.94) with real viscosity, simplifying shear rate/stress calculations; the equivalent viscosity index contains thermal/shearing history without corrections and strict velocity conditions; the equivalent weight index reflects ∼0.0001 g weight variation. The presented methods simplify the detection procedure, with potential for application in the field of precision products. [ABSTRACT FROM AUTHOR]

Reverse osmosis (RO) is a widely used membrane technology for producing process water or tap water that is receiving increased attention due to water scarcity caused by climate change. A significant challenge in any membrane filtration is the presence of deposits on the membrane surfaces, which negatively affect filtration performance. Biofouling, the formation of biological deposits, poses a significant challenge in RO processes. Early detection and removal of biofouling are essential for effective sanitation and prevention of biological growth in RO-spiral wound modules. This study introduces two methods for the early detection of biofouling, capable of identifying initial stages of biological growth and biofouling in the spacer-filled feed channel. One method utilizes polymer optical fibre sensors that can be easily integrated into standard spiral wound modules. Additionally, image analysis was used to monitor and analyze biofouling in laboratory experiments, providing a complementary approach. To validate the effectiveness of the developed sensing approaches, accelerated biofouling experiments were conducted using a membrane flat module, and the results were compared with common online and offline detection methods. The reported approaches enable the detection of biofouling before known online parameters become indicative, effectively providing an online detection with sensitivities otherwise only achieved through offline characterization methods.

A novel recyclable flexible SERS substrate with a hierarchical structure was fabricated by growing ZnO nanorods (ZnO NRs) on three-dimensional (3D) ordered cotton fabrics through a chemical hydrothermal method and depositing Ag nanoparticles (Ag NPs) on coral-like ZnO NRs. The Ag/ZnO/cotton fabrics (AZCF) exhibit superior SERS signals with a detection limit of 4-aminothiophenol (PATP) down to 10−10 M and an excellent uniformity (relative standard deviation lowered to less than 20 %). It also can achieve photocatalytic degradation of different substances, such as rhodamine 6G (R6 G), PATP and thiram. Furthermore, this SERS substrate was successfully applied to the in-situ detection of thiram on the surface of apple, and the detection limit is low to 5 mg/kg. Therefore, our studies not only constructed a promising SERS substrate with super sensitivity, good reproducibility and excellent stability for molecular detection, but also suggest a potential method for the actually in-situ detection of pesticide residues. [ABSTRACT FROM AUTHOR]

[Display omitted] • A bifunctional flexible SERS substrate is prepared. • SERS signal amplification and excellent sensitivity are achieved. • Rapid and efficient renewal is achieved under the visible light treatment. • The flexible substrate allows nondestructive and in-situ detection of real samples. Utilizing hydrothermal synthesis, TiO 2 and g-C 3 N 4 were grown on cotton fabric. Subsequently, Ag NPs were uniformly deposited on their surfaces to produce a Ag@g-C 3 N 4 /TiO 2 cotton fabric substrate (AGTC) with dual-functionalilites of photocatalytic reusability and SERS signal amplification. The introduction of TiO 2 and g-C 3 N 4 nanocomposites significantly enhances the SERS signal on the AGTC substrate for malachite green (MG) detection. The SERS signal on the AGTC substrate is 2.28 times stronger than that on the bare silver-modified cotton fabric, with a reduced detection limit of 6.74 × 10−13 M. Additionally, the Local Surface Plasmon Resonance (LSPR) effect induced by Ag NPs facilitates electron transfer among substrate components, markedly enhancing photocatalytic capability for degrading organic pollutants under visible light. Consequently, under visible light, the substrate rapidly degrades pollutants and reverts to a reusable state. Experimental results demonstrate the substrate's capability to continuously detect various concentrations and types of target substances, while maintaining high sensitivity. Leveraging the flexibility of cotton fabric, convenient wipe detection and self-cleaning experiments were conducted on the surfaces of different fish species, validating AGTC's outstanding sensitivity in real sample analysis. Therefore, as a flexible and reusable SERS substrate, AGTC exhibits broad potential applications in both SERS detection and photocatalytic degradation of pollutants. [ABSTRACT FROM AUTHOR]

Most in situ tool wear monitoring methods during micro end milling rely on signals captured from the machining process to evaluate tool wear behavior; accurate positioning in the tool wear region and direct measurement of the level of wear are difficult to achieve. In this paper, an in situ monitoring system based on machine vision is designed and established to monitor tool wear behavior in micro end milling of titanium alloy Ti6Al4V. Meanwhile, types of tool wear zones during micro end milling are discussed and analyzed to obtain indicators for evaluating wear behavior. Aiming to measure such indicators, this study proposes image processing algorithms. Furthermore, the accuracy and reliability of these algorithms are verified by processing the template image of tool wear gathered during the experiment. Finally, a micro end milling experiment is performed with the verified micro end milling tool and the main wear type of the tool is understood via in-situ tool wear detection. Analyzing the measurement results of evaluation indicators of wear behavior shows the relationship between the level of wear and varying cutting time; it also gives the main influencing reasons that cause the change in each wear evaluation indicator.

[Display omitted] • A novel and flexible electrochemical sensor is constructed for in-situ real-time monitoring of H 2 O 2 secreted by cells. • The 3D leaf-like nan-array structure of the electrode has a large electroactive surface area. • The Co-Nx sites generated by catalytic pyrolysis promote the adsorption and catalysis of H 2 O 2 on the surface of sensing electrode. Developing ultra-sensitive sensors for in-situ real-time monitoring of low-level cell secretions is of paramount importance in understanding various biological processes, and it is still a challenge. Herein, for the first time, we constructed a novel flexible Au-Co@C-CNT/CC sensing electrode with nano-array structures by in-situ synthesis, catalytic pyrolysis and electrochemical deposition, and successfully realized the real-time monitoring of H 2 O 2 released by cells. The 3D leaf-like structure of the electrode not only provided a large electroactive surface area (7.66 cm2) but also exhibited a microvilli structure of carbon nanotubes (CNT) on the surface, which further enhanced the presence of active sites. Moreover, the Co-Nx sites generated by catalytic pyrolysis can promote the adsorption and catalysis of H 2 O 2 on the surface of sensing electrode. The introduction of Au NPs facilitated the transfer of electrons, thereby enhancing the electrical conductivity and electrocatalytic performance of Au-Co@C-CNT/CC. Benefiting from these unique superiorities, this sensing platform displayed excellent performance for H 2 O 2 determination with a wide linear range (10–27080 μM) and low detection limit (0.13 μM). Notably, the good biocompatibility and flexibility of this sensing platform allowed direct culture of human lung cancer cells (A549 cells) on the electrodes, which can realize dynamic in-situ real-time detection of H 2 O 2 released by cells, showing great potential in the diagnosis of related diseases. [ABSTRACT FROM AUTHOR]

The unpredictable release behavior of metal nanoparticles/metal ions from metal nanoparticle-loaded hydrogels, without a suitable in situ detection method, is resulting in serious cytotoxicity. To optimize the preparation and design of antibacterial hydrogels for in situ detection of metal nanoparticles, an in-situ detection platform based on the fluorescence signal change caused by the potential surface energy transfer of silver nanoparticles (AgNPs) and carbon dots (CD) through silver mirror reaction and Schiff base reaction was established. The antimicrobial test results show that the composite antimicrobial hydrogel, with lower dosages of AgNPs and CD, exhibited a higher inhibition rate of 99.1 % against E. coli and 99.8 % against S. aureus compared to the single antimicrobial component. This suggests a potential synergistic antimicrobial activity. Furthermore, the fluorescence detection platform was established with a difference of <3 μg between detected values and actual values over a period of 72 h. This demonstrates the excellent in situ detection capability of the hydrogel in antimicrobial-related applications. [Display omitted] • The energy transfer within the hydrogels enables in-situ monitoring of the dynamic release behavior of silver nanoparticles. • Schiff base bond, hydrogen bonds, and electrostatic interactions collectively enhance the network structure of hydrogels. • Silver nanoparticles were prepared through the silver mirror reaction without the use of chemical reductants or surfactants. [ABSTRACT FROM AUTHOR]

Thiram (THR) belongs to the dithiocarbamate family with a molecular formula of C 6 H 12 N 2 S 4. THR represents one of the most common pesticides, used as an antifungal candidate worldwide. Notably, THR displays several intricate adverse impacts on living organisms' health. Therefore, the detection process of THR on fruit surfaces is critical for guaranteeing food safety. Herein, a flexible sensor coupled with intelligent algorithms was developed for the accurate and rapid in-situ detection of pesticide residues, in particular thiram on apple surfaces. A flexible sensor of surface-enhanced Raman spectroscopy (SERS) was constructed by assembling mercaptoacetic acid-modified core-shell gold-silver nanorods (Au@AgNRs/MAA) on an ammoniated polydimethylsiloxane (PDMS) layer. The high transparency and flexibility of the film enabled the in-situ collection of SERS signals. Subsequently, three intelligent algorithms were employed, and their performance in foretelling THR residues on apple surfaces was compared and evaluated. The competitive adaptive reweighted sampling (CARS) algorithm depicted the potent accurate forecasts, with a prediction correlation coefficient (R p) of 0.9934 and a root mean square error of prediction (RMSEP) of 0.6969 mg/L. Since the suggested approach has the advantages of being simple, speedy, and sensitive, it will be a tremendous promise for quick and non-destructive examination of surface pollutants in the realm of food safety. • SERS sensor showed excellent flexibility and storage stability. • Assembling Au@AgNRs/MAA on ammoniated PDMS film. • Au@AgNRs/MAA possesses high sensitivity and stability. • Three intelligent algorithms were compared and evaluated. [ABSTRACT FROM AUTHOR]

Single cell heterogeneity plays an important role in many biological phenomena and distinguishing cells that exhibit certain mutation in sample could benefit clinical diagnose and drug screening. Typical single cell detection methods such as flow cytometry, in-situ hybridization, real-time amplification or sequencing test either protein or nucleic acid as target and usually require specialized instruments. Joint measurement of the both types of targets could be done by combining the above strategies precisely but also unwieldly. Methods for rapidly and parallelly screening single cells with target genotype and antigen is needed. In this study, we describe a gel plate platform to distinguish cell types based on their phenotypes on target gene and antigen with low equipment requirement. Integrated cell lysis and immobilization were done in the gel solidification step, after which antibody hybridization and real-time amplification were sequentially carried out without losing the original loci information of individual single cells so the three types of information of individual single cells could be combined to distinguished cells with expected genotype and phenotype. The easy-to-use gel platform has potential in point-of-care circumstances and single-cell stimulation response that have high requirements on efficiency and simplicity. [Display omitted] • Single cells were immobilized in a gel plate where antibody hybridization and real-time LAMP were sequentially performed. • Cell lysis and lysate immobilization were done simultaneously in the gel plate solidification step. • Types of cells in mixture were differentiated based on their genotypes and phenotypes. • More detecting methods are expected on the gel plate constructed with highly bio-compatible agarose. [ABSTRACT FROM AUTHOR]

Numerous natural biological materials have been used in surface-enhanced Raman scattering due to the unique properties contributed by their composite structures on the surface, yet the fragility of these materials limits their application prospects. In this study, a rose-petal-like substrate was constructed by imitating the structure of fresh rose petals on the surface of polydimethylsiloxane for direct sampling and in-situ Raman detection. These substrates were created with high precision based on molding the fresh rose petals. The unique three-dimensional structures endow the prepared substrate with excellent hydrophobicity (141.3°) and large specific surface area for holding more hotspots under one laser shot. After loading silver nanoparticles, the substrate exhibited good repeatability (relative standard deviation was 11.5%), and excellent detection limit (10–15 mol·L−1) with rhodamine 6G as the probe molecule. In particular, attributed to its inherent flexibility, the substrate was used for direct sampling and detection of pesticide molecules, such as thiram and methyl parathion, on the apple peels, and the detection limits were found to be 1.8 and 1.2 ng·cm−2, respectively. The results show the ability of the substrate in in-situ sampling and detection, demonstrating significant potential in practical applications. [Display omitted] • A flexible SERS substrate was fabricated by imitating the rose petal. • Batch replication can be achieved using the self-made template. • The SERS substrate exhibits great sensitivity and mechanical stability. • Rapid sampling and in-situ Raman detection were realized using the substrate. [ABSTRACT FROM AUTHOR]

In aqueous redox flow batteries (ARFBs), the redox reaction of K 4 [Fe(CN) 6 ]/K 3 [Fe(CN) 6 ] is commonly applied as an active material for the positive electrode. Its performance is restrained by inhomogeneous electrochemical activity and oxygen evolution side reactions. The activity of both the redox reaction and the side reaction lacks two-dimensional detection method. In this study, ion concentration variations on the electrode surface are converted into refractive index changes by a total internal reflection (TIR) imaging system, which enables characterization of the two-dimensional distributions of surface activity and oxygen evolution reactions (OER) onset potential on the ARFBs positive electrode. This method can obtain the two-dimensional maps of parameters of cyclic voltammetry (CV) and the onset potential of the OER. We validate the feasibility of this method by examining three different electrodes and an electrochemical stability test. This work offers a characterization tool for developing homogeneous electrodes with enhanced activity, high reversibility, and minimized OER side reactions. In aqueous redox flow batteries (ARFBs), electrode two-dimensional distributions of electrochemical activity and oxygen evolution side reactions can be detected by a total internal reflection (TIR) imaging system. [Display omitted] • In-situ mapping of electrode activity and OER side reaction distribution. • Two-dimensional visualization of real-time electrochemical parameters. • Guide the preparation of more homogeneous, higher-activity electrodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Using bionic gas sampler quickly collected the odor information of multi-brand pesticides in soil. • Using bionic learning cognitive strategies identified pesticides never before seen in soil. • Using bionic sniffing sensing system realized pesticides detection under premise of low price and easy operation. Rapid identification of pesticides in soil is the foundation of soil health management and precise pollution remediation. In this study, we firstly proposed to use bionic sniffing sensing system with unknown category detection function for rapid identification of pesticides in soil. This proposed system achieves optimal performance by integrating a bionic gas sampler and bionic identification strategy. Concerning the bionic gas sampler, we developed a complex trace gas bionic sampler based on the structure of human nasal concha to collect odor information from various brands and types of pesticides. Regarding the bionic identification strategies, we took human category learning process as bionic prototype and designed bionic learning cognitive strategy. Experimental results demonstrate that developed gas sampler effectively captures the odor information emitted from diverse pesticides in soil. And the proposed bionic learning cognitive strategy shows good performance in unknown category detection, detection accuracy, detection time and model updating ability. The proposed system has advantages such as cost-effectiveness, speed, convenience, in-situ detection. This work will contribute to the detection and treatment of pesticides in soil. [ABSTRACT FROM AUTHOR]

• ASMR: A concept of spectral signal enhancement within optical-length-limited vials. • The detection performances of 2/4/6/8-ASMR have been verified and evaluated. • 2-ASMR performs more industrial value for better resisting angular uncertainties. • 8-ASMR achieves better performance in concentration discriminative and stability. In-situ and accurate residual oxygen concentration detection in glass vials is an urgent topic in the pharmaceutical manufacturing industry, as the headspace oxygen would render the inner drug composition spoiled. In this paper, an oxygen detection method is designed based on wavelength-modulated tunable diode laser absorption spectroscopy (TDLAS-WMS). To be specific, a concept of coating the outer surface of the vial with a high-reflection silver ring film is firstly proposed, which assists the laser to achieve A xis- S ectional M ulti- R eflection (ASMR) in the narrow space of the vial to break through the optical path limitation of traditional D irect- T ransmission (DT) detection method. We abbreviate ASMR with the reflection number of n as n -ASMR. The experimental results prove 2/4/6/8-ASMR performs better stability and detection limit of 0.058%/0.054%/0.058%/0.046% with the integrate time of 28.9s/14.6s/4.76s/5.60s, compared with 0.22% for DT with 33.8s. Specially, 2-ASMR performs great application potential for its best ability to resist angle change. [ABSTRACT FROM AUTHOR]

Developing versatile printing inks with good biocompatibility is essential for the fabrication of functional colored contact lenses. In this work, by employing a new kind of printing ink that shows humidity-induced discoloration, multifunctional colored contact lenses have been constructed. The obtained products have displayed distinct and stable all-weather humidity-triggered discoloration under ambient conditions. More importantly, combined with a smartphone, the quantitative and qualitative relationship between the discoloration of colored contact lenses and environmental humidity has been established, which is expected to realize the early prediction of humidity-related eye diseases in a portable, economical, and in-situ manner. • A new kind of printing ink that shows humidity-induced discoloration has been prepared. • The colored contact lens with all-weather humidity-triggered discoloration has been constructed. • The quantitative and qualitative relationship between the discoloration of colored contact lenses and environmental humidity has been established. [ABSTRACT FROM AUTHOR]

In-situ detection provides deep insights into the function of genes and their relationship with diseases by directly visualizing their spatiotemporal behavior. As an emerging in-situ imaging tool, clustered regularly interspaced short palindromic repeats (CRISPR)-mediated bioimaging can localize targets in living and fixed cells. CRISPR-mediated bioimaging has inherent advantages over the gold standard of fluorescent in-situ hybridization (FISH), including fast imaging, cost-effectiveness, and ease of preparation. Existing reviews have provided a detailed classification and overview of the principles of CRISPR-mediated bioimaging. However, the exploitation of potential clinical applicability of this bioimaging technique is still limited. Therefore, analyzing the potential value of CRISPR-mediated in-situ imaging is of great significance to the development of bioimaging. In this review, we initially discuss the available CRISPR-mediated imaging systems from the following aspects: summary of imaging substances, the design and optimization of bioimaging strategies, and factors influencing CRISPR-mediated in-situ detection. Subsequently, we highlight the potential of CRISPR-mediated bioimaging for application in biomedical research and clinical practice. Furthermore, we outline the current bottlenecks and future perspectives of CRISPR-based bioimaging. We believe that this review will facilitate the potential integration of bioimaging-related research with current clinical workflow. • In-situ imaging is useful for understanding gene function and disease occurrence. • CRISPR-mediated bioimaging system provide an opportunity for in-situ imaging. • Low signal-to-noise ratio remains a major challenge for imaging. • Analyzing principles and influencing factors helps to optimize the imaging results. • Essential considerations remain before the CRISPR system goes clinical. [ABSTRACT FROM AUTHOR]

This work describes an unconventional voltammetric detection in a gas medium using a suspended electrode unit. A paper moistened with the supporting electrolyte is used to absorb the gas. This concept was demonstrated for the in-situ detection of SO 2 gas to quantify sulfite residue in samples of frozen shrimp. The gas is generated by the acidification of an aqueous suspension of shrimp tissues. The porosity of facial tissue paper is employed to provide a liquid layer of supporting electrolyte for the operation of the gold leaf electrochemical sensor. The absorbed gas is also dissolved in this liquid layer. The gold leaf sensor is reusable by replacing the tissue disc and rinsing the electrodes with water. The electrochemical sensor does not require refrigeration or pre-conditioning as with commercial biosensors and is thus suitable for point-of-need purposes. Production of the gold leaf sensor is only ca. 0.2 USD per unit and can be used regularly for up to 3 months. The linear calibration range of spiked negative control shrimp samples is from 3 to 240 mg kg−1 SO 2 for a 30 mL solution of an extract of 5.0 g homogenized defrosted shrimp. The limit of detection (3 ×SD intercept /slope) for spiked samples is 2 mg kg−1 SO 2. This is the first electrochemical sensor in a gas medium exploiting the entrapment of electrolyte solution inside a porous substrate. [Display omitted] • Concept of electrochemical detection in gas medium for zero-fouling of electrodes. • Moist facial tissue as disposable porous substrate for reusable gold leaf sensor. • A thin liquid layer as gas absorbent and background electrolyte. • Suitable for onsite analysis of sulfite residue in shrimp at regulatory levels. • Complete rapid point-of need unit without ex-situ extraction or centrifugation. [ABSTRACT FROM AUTHOR]

An essential aspect for the wide practical application of surface-enhanced Raman spectroscopy (SERS) lies in the further improvement of its sensitivity. In this paper, a strengthened chemical effect with a high enhancement factor (EF) of 3.9 × 107 was first triggered through simply adjusting the heterojunction structure between graphitic carbon nitride (g-C 3 N 4) flake and molybdenum disulfide (MoS 2) nanoflower. Ag nanoparticles (Ag NPs) were then photo-reduced onto the g-C 3 N 4 @MoS 2 matrix to introduce significant steric electromagnetic field under excitation, which was further reinforced by provoking a resonance coupling effect based on graphene oxide (GO) resonant cavity. Such a cavity was set between the g-C 3 N 4 @MoS 2 @Ag-polydimethylsiloxane (PDMS) matrix and the Ag nanocubes (Ag NCs)-embedded PDMS coating membrane, facilitating a robust flexible SERS chip with a promising EF attained as 1.1 × 109. Additionally, the SERS intensity was only decreased by 5% after three months, indicating the excellent stability of the as-prepared bilayer SERS chip. The on-site reclaimable monitoring for thiram (TMTD) and methyl parathion (MP) accompanied by a low limit of detection (LOD) of 10−6 mg/mL was achieved by utilizing the proposed sophisticated SERS chip, demonstrating its fascinating application feasibility. [Display omitted] • A structure-ameliorated chemical enhancement was triggered by the heterojunction of g-C 3 N 4 flake and MoS 2 nanoflower. • A remarkable electromagnetic resonant effect with a high EF of 1.1 × 109 was facilitated by nanoscale GO resonant cavity. • The versatile bilayer membrane chip demonstrated an on-site reclaimable monitoring of pesticides with a LOD of 10−6 mg/mL. [ABSTRACT FROM AUTHOR]