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High sensitivity is often considered a characteristic of giftedness, but scientific evidence for this is limited. Therefore, this study aimed to investigate whether gifted children rate themselves higher in sensory processing sensitivity (SPS) than their peers. A total of 882 children from Grades 4, 5, and 6 of primary school participated. They all completed a cognitive ability test (COVAT-3) and two self-report questionnaires to assess SPS (HSC scale and ChiSSEQ). The results revealed that the 10% best-performing children on the cognitive ability test did not differ significantly from their peers in SPS. There was one exception: Only on the HSC scale did children with high cognitive abilities score higher than those with low abilities (not higher than those with average and above-average abilities). However, this difference disappeared when applying stricter cut-offs to define high cognitive abilities. [ABSTRACT FROM AUTHOR]

A novel chitosan (CS) functionalized optical fiber sensor with a bullet-shaped hollow cavity was proposed in this work for the trace concentration of Pb2+ ion detection in the water environment. The sensor is an optical fiber Mach–Zehnder interferometer (MZI), which consists of a sequentially spliced bullet-shaped hollow-core fiber (HCF), thin-core fiber, and another piece of spliced bullet-shaped HCF. The hollow-core fiber is caused to collapse by adjusting the amount of discharge to form a tapered hollow cavity with asymmetric end faces. The bullet-like hollow cavities act as beam expanders and couplers for optical fiber sensors, which were symmetrically spliced at both ends of a section of thin core fiber. The simulation and experiments show that the bullet-like hollow-core tapered cavity excites more cladding modes and is more sensitive to variation in the external environment than the planar and spherical cavities. The ion-imprinted chitosan (IIP-CS) film was fabricated with Pb2+ ion as a template and uniformly coated on the surface for specific recognition of Pb2+. Experimental verification confirms that the developed sensor can achieve high-sensitivity Pb2+ ion detection, with a sensitivity of up to −12.68 pm/ppm and a minimum Pb2+ ion detection concentration of 5.44 ppb Meanwhile, the sensor shows excellent selectivity, repeatability, and stability in the ion detection process, which has huge potential in the direction of heavy metal ion detection in the future. [ABSTRACT FROM AUTHOR]

David Wagenfeld, an artist and resident of Kalamazoo, Michigan, provided the cover art for the Summer 2024 edition of The Open Journal of Occupational Therapy (OJOT). “Word Fusion” is a piece made from ink on paper that uses words to depict an image of a person walking through an environment. The image is rooted to the ground in love, joy, calmness, and peace. The person is one with themselves and their spirituality with arms portraying presence, joy, and serenity. David shares his experience of self-discovery and understanding of the beautiful dance between art and spirituality. [ABSTRACT FROM AUTHOR]

This article presents a highly sensitive plasmonic sensor with a focus on enhancing its capabilities through innovative design and simple geometric structure. A hexagonal-shaped photonic crystal fiber (PCF) based surface plasmon resonance sensor is designed and proposed for external sensing applications. The plasmonic material is made of gold and positioned on the outer side of the designed PCF. For detection purposes, the flow of the testing analyte is introduced on the exterior section of the PCF. The sensing capability of this innovative sensor is meticulously examined using the finite element technique facilitated by the COMSOL Multiphysics software. The suggested sensor, with a refractive index of 1.38, has a maximum amplitude sensitivity and wavelength sensitivity of 765.86 RIU−1 and 8,000 nm/RIU respectively. At the same refractive index, the sensing resolution of the sensor is 1.31 × 10–5 for amplitude sensitivity and 1.25 × 10–5 for wavelength sensitivity. Additionally, the sensing capability of the sensor lies in the range of the analyte refractive indices from 1.33 to 1.39. Furthermore, the sensing performance of the designed sensor is analyzed by optimizing the values of several design parameters including air-hole diameter, pitch, and gold layer thickness. The suggested sensor can recognize biological analytes with high sensitivity, improved sensing resolution, and appropriate linearity. [ABSTRACT FROM AUTHOR]

Since different quantities of white blood cells (WBCs) in solution possess an adaptive osmotic pressure of cells, the WBCs themselves and in solution have similar concentrations, resulting in them having similar dielectric properties. Therefore, a microwave sensor could have difficulty in sensing the quantity variation when WBCs are in solution. This paper presents a highly sensitive, linear permittivity-inspired microwave biosensor for WBCs, counting through the evaporation method. Such a measurement method is proposed to record measurements after the cell solution is dripped onto the chip and is completely evaporated naturally. The proposed biosensor consists of an air-bridged asymmetric differential inductor and a centrally located circular fork-finger capacitor fabricated on a GaAs substrate using integrated passive fabrication technology. It is optimized to feature a larger sensitive area and improved Q-factor, which increases the effective area of interaction between cells and the electromagnetic field and facilitates the detection of their changes in number. The sensing relies on the dielectric properties of the cells and the change in the dielectric constant for different concentrations, and the change in resonance properties, which mainly represents the frequency shift, corresponds to the macroscopic change in the concentration of the cells. The microwave biosensors are used to measure biological samples with concentrations ranging from 0.25 × 106 to 8 × 106 cells per mL in a temperature (26.00 ± 0.40 °C) and humidity (54.40 ± 3.90 RH%) environment. The measurement results show a high sensitivity of 25.06 Hz/cells·mL−1 with a highly linear response of r2 = 0.99748. In addition, a mathematical modeling of individual cells in suspension is performed to estimate the dielectric constant of individual cells and further explain the working mechanism of the proposed microwave biosensor. [ABSTRACT FROM AUTHOR]

Monkeypox virus (MPXV), the pathogen responsible for the infectious disease monkeypox, causes lesions on the skin, lymphadenopathy, and fever. It has posed a global public health threat since May 2022. Highly sensitive and specific detection of MPXV is crucial for preventing the spread of the disease. Pyrococcus furiosus Argonaute (PfAgo) is an artificial DNA-guided restriction cleavage enzyme programmable with 5′-phosphorylated ssDNA sequences, which can be developed to specifically detect nucleic acids of pathogens. Here, a PfAgo-based system was established for the detection of MPXV-specific DNA targeting the F3L gene. A short amplicon of 79 bp could be obtained through a fast PCR procedure, which was completed within 45 min. Two 5′-phosphorylation guide DNAs were designed to guide PfAgo to cleave the amplicon to obtain an 18 bp 5′-phosphorylation sequence specific to MPXV, not to other orthopoxviruses (cowpox, variola, and vaccinia viruses). The 18 bp sequence guided PfAgo to cleave a designed probe specific to MPXV to emit fluorescence. With optimized conditions for the PfAgo-MPXV system, it could be completed in 60 min for the detection of the extracted MPXV DNA with the limit of detection (LOD) of 1.1 copies/reaction and did not depend on expensive instruments. Successful application of the PfAgo-MPXV system in sensitively detecting MPXV in simulated throat swabs, skin swabs, sera, and wastewater demonstrated the system's good performance. The PfAgo platform, with high sensitivity and specificity established here, has the potential to prevent the spread of MPXV. [ABSTRACT FROM AUTHOR]

Flexible wearable strain sensors are crucial in human–machine interfaces, electronic skins, and human movement detection. However, simultaneously achieving high sensitivity and a large response range persists as a significant issue, and trade-offs often exist between them. In this work, thermoplastic polyurethane (TPU) fibrous membranes are prepared by utilizing electrospinning technology and used as a flexible substrate. Silver nanoparticles (AgNPs) are securely sputtered on the TPU fibrous membrane by magnetron sputtering, which enhances the sensitivity due to their small dimensions. Meanwhile, CNTs were anchored through ultrasonication to serve as an additional conductive layer to expand the response range due to their large aspect ratio. The obtained TPU/Ag/CNT fibrous membrane possesses exceptional mechanical properties (stress up to 10.44 MPa, strain up to 606.7%). The TPU/Ag/CNT-based strain sensor exhibits remarkable sensing properties of high sensitivity (gauge factor up to 6834), a large response range (up to 604% strain), and fast response and recovery times (response time is 122 ms, recovery time is 164 ms), along with an extremely low detection limit (0.1%). Moreover, it shows remarkable cycling stability, maintaining its performance for over 1000 cycles. Due to these outstanding advantages, TPU/Ag/CNT strain sensors have exceptional capacity to detect human movement and demonstrate a certain potential in the development of flexible strain sensors. [ABSTRACT FROM AUTHOR]

The introduction of porous hierarchical microstructures effectively improves the sensitivity of flexible pressure sensors. However, it is difficult to achieve porous hierarchical microstructures for pressure sensors through inexpensive, efficient, and simple preparation methods. Herein, a hemispherical array with porous hierarchical microstructure is prepared on polydimethylsiloxane substrate using a simple one‐step microwave curing process with glucose as porogen. Furthermore, the flexible electrode based on the polydimethylsiloxane substrate is combined with an ionic liquid polymeric gel membrane to obtain a flexible capacitive pressure sensor. Thanks to the deformability of porous hierarchical microstructure and the double‐dielectric layer effect of ionic liquid polymeric gel membrane, the sensor displays an ultrahigh sensitivity of 131.21 kPa−1 within 0–1 kPa. Meanwhile, the sensor has short response time, excellent dynamic loading stability, as well as excellent long‐term stability (>3000 cycles). In application testing, the sensor effectively monitors various physiological activities like pulse, breathe, speech, and swallowing, demonstrating its good prospects in the field of health electronics. Most importantly, the proposed microwave curing method can realize the preparation of porous hierarchical structure on flexible substrate through a one‐step process, which offers a fresh way for the economical, green, and efficient preparation of high‐sensitivity capacitive pressure sensors. [ABSTRACT FROM AUTHOR]

Gold and silver are the two notable noble metals with wide implications in surface plasmon resonance (SPR) based sensors. Gold possesses a superior SPR phenomenon compared to silver, however, with extremely high costs. To resolve this problem, the current study proposes a new gold–free SPR biosensor design employing silver as the noble metal for efficient detection of blood glucose using urine as the biosample. The proposed design employs two types of 2D materials such as graphene and tungsten disulfide (WS2) to enhance the sensitivity of the silver-based SPR biosensor. An investigation for design of a low-cost biosensor for urine-glucose detection is done using the proposed configuration. The glucose concentration in the biosample ranges from 0 to 15 mg/dl (for normal persons) and 0.625 gm/dL, 1.25 gm/dL, 2.5 gm/dL, 5 gm/dL, and 10 gm/dL (for diabetic persons), with corresponding refractive indices of 1.335, 1.336, 1.337, 1.338, 1.341, and 1.347. The material's type, order, and thickness have been chosen through numerous case studies. It is worth noting that, with 4-layer graphene (0.34 nm) and 4-layer WS2 (0.8 nm), the proposed silver-based SPR biosensor shows improved sensitivity (288.86o/RIU) and figure of merit (88.89/RIU) than its gold-based counterpart (sensitivity 150o/RIU). Finally, this study is also compared with similar reported literatures. The proposed structure has potential to develop low-cost and efficient SPR-based biosensors (glucose sensors), with a substantial shift in resonance angle of SPR curves as shown in the present study. [ABSTRACT FROM AUTHOR]

A novel chitosan (CS) functionalized optical fiber sensor with a bullet-shaped hollow cavity was proposed in this work for the trace concentration of Pb2+ ion detection in the water environment. The sensor is an optical fiber Mach–Zehnder interferometer (MZI), which consists of a sequentially spliced bullet-shaped hollow-core fiber (HCF), thin-core fiber, and another piece of spliced bullet-shaped HCF. The hollow-core fiber is caused to collapse by adjusting the amount of discharge to form a tapered hollow cavity with asymmetric end faces. The bullet-like hollow cavities act as beam expanders and couplers for optical fiber sensors, which were symmetrically spliced at both ends of a section of thin core fiber. The simulation and experiments show that the bullet-like hollow-core tapered cavity excites more cladding modes and is more sensitive to variation in the external environment than the planar and spherical cavities. The ion-imprinted chitosan (IIP-CS) film was fabricated with Pb2+ ion as a template and uniformly coated on the surface for specific recognition of Pb2+. Experimental verification confirms that the developed sensor can achieve high-sensitivity Pb2+ ion detection, with a sensitivity of up to −12.68 pm/ppm and a minimum Pb2+ ion detection concentration of 5.44 ppb Meanwhile, the sensor shows excellent selectivity, repeatability, and stability in the ion detection process, which has huge potential in the direction of heavy metal ion detection in the future.

Since different quantities of white blood cells (WBCs) in solution possess an adaptive osmotic pressure of cells, the WBCs themselves and in solution have similar concentrations, resulting in them having similar dielectric properties. Therefore, a microwave sensor could have difficulty in sensing the quantity variation when WBCs are in solution. This paper presents a highly sensitive, linear permittivity-inspired microwave biosensor for WBCs, counting through the evaporation method. Such a measurement method is proposed to record measurements after the cell solution is dripped onto the chip and is completely evaporated naturally. The proposed biosensor consists of an air-bridged asymmetric differential inductor and a centrally located circular fork-finger capacitor fabricated on a GaAs substrate using integrated passive fabrication technology. It is optimized to feature a larger sensitive area and improved Q-factor, which increases the effective area of interaction between cells and the electromagnetic field and facilitates the detection of their changes in number. The sensing relies on the dielectric properties of the cells and the change in the dielectric constant for different concentrations, and the change in resonance properties, which mainly represents the frequency shift, corresponds to the macroscopic change in the concentration of the cells. The microwave biosensors are used to measure biological samples with concentrations ranging from 0.25 × 106 to 8 × 106 cells per mL in a temperature (26.00 ± 0.40 °C) and humidity (54.40 ± 3.90 RH%) environment. The measurement results show a high sensitivity of 25.06 Hz/cells·mL−1 with a highly linear response of r2 = 0.99748. In addition, a mathematical modeling of individual cells in suspension is performed to estimate the dielectric constant of individual cells and further explain the working mechanism of the proposed microwave biosensor.

Monkeypox virus (MPXV), the pathogen responsible for the infectious disease monkeypox, causes lesions on the skin, lymphadenopathy, and fever. It has posed a global public health threat since May 2022. Highly sensitive and specific detection of MPXV is crucial for preventing the spread of the disease. Pyrococcus furiosus Argonaute (PfAgo) is an artificial DNA-guided restriction cleavage enzyme programmable with 5′-phosphorylated ssDNA sequences, which can be developed to specifically detect nucleic acids of pathogens. Here, a PfAgo-based system was established for the detection of MPXV-specific DNA targeting the F3L gene. A short amplicon of 79 bp could be obtained through a fast PCR procedure, which was completed within 45 min. Two 5′-phosphorylation guide DNAs were designed to guide PfAgo to cleave the amplicon to obtain an 18 bp 5′-phosphorylation sequence specific to MPXV, not to other orthopoxviruses (cowpox, variola, and vaccinia viruses). The 18 bp sequence guided PfAgo to cleave a designed probe specific to MPXV to emit fluorescence. With optimized conditions for the PfAgo-MPXV system, it could be completed in 60 min for the detection of the extracted MPXV DNA with the limit of detection (LOD) of 1.1 copies/reaction and did not depend on expensive instruments. Successful application of the PfAgo-MPXV system in sensitively detecting MPXV in simulated throat swabs, skin swabs, sera, and wastewater demonstrated the system’s good performance. The PfAgo platform, with high sensitivity and specificity established here, has the potential to prevent the spread of MPXV.

1. Sex chromosomes of emus are largely homomorphic. Therefore, the standard methodology for molecular sexing based on screening intron length variations in sex-linked genes is not applicable. However, emu sexing requires costly and time-consuming PCR-RFLP or multiplex PCR methods. 2. This experiment used a directed PCR amplification and capillary electrophoresis sexing protocol. Two distinct peaks were observed in females (ZW), while only one peak was observed in males (ZZ). 3. This sexing technique proved to be rapid, non-invasive, and highly sensitive and may be useful for verifying the sex ratio and breeding management of emus. [ABSTRACT FROM AUTHOR]

Objectives: The World Health Organization (WHO) Global tuberculosis Report 2021 stated that rifampicin-resistant tuberculosis (RR-TB) remains a major public health threat. However, the in-practice diagnostic techniques for RR-TB have a variety of limitations including longer time, lack of sensitivity, and undetectable low proportion of heterogeneous drug resistance. Methods: Here we developed a multiplex LNA probe-based RAP method (MLPRAP) for more sensitive detection of multiple point mutations of the RR-TB and its heteroresistance. A total of 126 clinical isolates and 78 sputum samples collected from the National Tuberculosis Reference Laboratory, China CDC, were tested by MLP-RAP assay. In parallel, qPCR and Sanger sequencing of nested PCR product assay were also performed for comparison. Results: The sensitivity of the MLP-RAP assay could reach 5 copies/ml using recombinant plasmids, which is 20 times more sensitive than qPCR (100 copies/ml). In addition, the detection ability of rifampicin heteroresistance was 5%. The MLP-RAP assay had low requirements (boiling method) for nucleic acid extraction and the reaction could be completed within 1 h when placed in a fluorescent qPCR instrument. The result of the clinical evaluation showed that the MLP-RAP method could cover codons 516, 526, 531, and 533 with good specificity. 41 out of 78 boiled sputum samples were detected positive by MLPRAP assay, which was further confirmed by Sanger sequencing of nested PCR product assay, on the contrary, qPCR was able to detect 32 samples only. Compared with Sanger sequencing of nested PCR product assay, both the specificity and sensitivity of the MLP-RAP assay were 100%. Conclusion: MLP-RAP assay can detect RR-TB infection with high sensitivity and specificity, indicating that this assay has the prospect of being applied for rapid and sensitive RR-TB detection in general laboratories where fluorescent qPCR instrument is available. [ABSTRACT FROM AUTHOR]

Stretchable electronic skin (e‐skin) paves the way for applications that exceed the scope of intrinsic rigid devices and hard‐to‐stretch sensors. The broad application range of flexible e‐skins benefits from device architectures that can simultaneously provide mechanical flexibility and superior sensitivity. Classic fractal design provides a simple architecture to achieve the desired flexibility through structural design for improved wear comfort, but at the expense of sensor sensitivity. In this study, the proposed method addresses the trade‐off between stretchability and sensitivity in fractal design. A high‐sensitivity e‐skin is obtained by eliminating the effect of negative charge on the output by applying the concept of electromechanical coupling. This concept for designing e‐skins with high sensitivity is validated through the delicate patterning of hard‐to‐stretch functional materials. Further, human speech signals are acquired through the integration of e‐skin with signal processing circuits, and speech pattern recognition is realized using machine learning. The stretchable e‐skin with an enhanced gauge factor illustrates the wider application of this concept for improving the sensitivity of stretchable electronic functional materials. [ABSTRACT FROM AUTHOR]

In atherosclerosis, chronic inflammatory processes in local diseased areas may lead to the accumulation of reactive oxygen species (ROS). In this study, we devised a highly sensitive H2O2-scavenging nano-bionic system loaded with probucol (RPP-PU), to treat atherosclerosis more effectively. The RPP material had high sensitivity to H2O2, and the response sensitivity could be reduced from 40 to 10 μmol/L which was close to the lowest concentration of H2O2 levels of the pathological environment. RPP-PU delayed the release and prolonged the duration of PU in vivo. In Apolipoprotein E deficient (ApoE‒/‒) mice, RPP-PU effectively eliminated pathological ROS, reduced the level of lipids and related metabolic enzymes, and significantly decreased the area of vascular plaques and fibers. Our study demonstrated that the H2O2-scavenging nano-bionic system could scavenge the abundant ROS in the atherosclerosis lesion, thereby reducing the oxidative stress for treating atherosclerosis and thus achieve the therapeutic goals with atherosclerosis more desirably.

Abstract Stretchable electronic skin (e‐skin) paves the way for applications that exceed the scope of intrinsic rigid devices and hard‐to‐stretch sensors. The broad application range of flexible e‐skins benefits from device architectures that can simultaneously provide mechanical flexibility and superior sensitivity. Classic fractal design provides a simple architecture to achieve the desired flexibility through structural design for improved wear comfort, but at the expense of sensor sensitivity. In this study, the proposed method addresses the trade‐off between stretchability and sensitivity in fractal design. A high‐sensitivity e‐skin is obtained by eliminating the effect of negative charge on the output by applying the concept of electromechanical coupling. This concept for designing e‐skins with high sensitivity is validated through the delicate patterning of hard‐to‐stretch functional materials. Further, human speech signals are acquired through the integration of e‐skin with signal processing circuits, and speech pattern recognition is realized using machine learning. The stretchable e‐skin with an enhanced gauge factor illustrates the wider application of this concept for improving the sensitivity of stretchable electronic functional materials.

Abstract Background Viral antigen detection test is the most common method used to detect viruses in the field rapidly. However, due to the low sensitivity, it can only be used as an auxiliary diagnosis method for virus infection. Improving sensitivity is crucial for developing more accurate viral antigen tests. Nano luciferase (Nluc) is a sensitive reporter that has not been used in virus detection. Results In this study, we produced an intracellularly Nluc labeled detection antibody (Nluc-ch2C5) and evaluated its ability to improve the detection sensitivity of respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens. Compared with the traditional horse-radish peroxidase (HRP) labeled antibody (HRP-ch2C5), Nluc-ch2C5 was 41 times more sensitive for inactivated SARS-CoV-2 virus by sandwich chemiluminescence ELISA. Then we applied Nluc-ch2C5 to establish an automatic magnet chemiluminescence immune assay (AMCA) for the SARS-CoV-2 viral spike protein, the limit of detection was 68 pfu/reaction. The clinical sensitivity and specificity reached 75% (24/32) and 100% (48/48) using 32 PCR-positive and 48 PCR-negative swab samples for clinical evaluation, which is more sensitive than the commercial ELSA kit and colloid gold strip kit. Conclusions Here, monoclonal antibody ch2C5 served as a model antibody and the SARS-CoV-2 served as a model pathogen. The Nluc labeled detecting antibody (Nluc-ch2C5) significantly improved the detection sensitivity of SARS-CoV-2 antigen. This labeling principle applies to other viral infections, so this labeling and test format could be expected to play an important role in detecting other virus antigens.

Temperature is an important physical parameter and plays a significant role in scientific research, the detection of which cannot be too crucial to study. In order to reduce the interference of the external environment on the detection of temperature and improve the accuracy of the detection results, a multi-parameter detection method using several optical signals was proposed. Here, a novel porous metal–organic framework (MOF), Zn-CYMPN, was synthesized and structurally characterized. Then, fluorescent organic dyes, either DPEE or DPEM, were encapsulated into the pores of Zn-CYMPN independently. The successful synthesis of the composites Zn-CYMPN⊃DPEE or Zn-CYMPN⊃DPEM could easily introduce other fluorescent centers into the original material and made it more convenient to realize multi-parameter temperature detection. More specifically, when the temperature changed, the maximum fluorescent emission wavelength (W) and the maximum optical intensity (I) of the Zn-CYMPN⊃DPEE/DPEM both showed good linear responses with temperature over a wide range, indicating that the composites were highly sensitive thermometers with multi-parameter temperature readouts. In addition, the quantum efficiency and thermal stability of the organic dyes, which bother every researcher, were improved as well. [ABSTRACT FROM AUTHOR]

In atherosclerosis, chronic inflammatory processes in local diseased areas may lead to the accumulation of reactive oxygen species (ROS). In this study, we devised a highly sensitive H 2 O 2 -scavenging nano-bionic system loaded with probucol (RPP-PU), to treat atherosclerosis more effectively. The RPP material had high sensitivity to H 2 O 2 , and the response sensitivity could be reduced from 40 to 10 μmol/L which was close to the lowest concentration of H 2 O 2 levels of the pathological environment. RPP-PU delayed the release and prolonged the duration of PU in vivo. In Apolipoprotein E deficient (ApoE‒/‒) mice, RPP-PU effectively eliminated pathological ROS, reduced the level of lipids and related metabolic enzymes, and significantly decreased the area of vascular plaques and fibers. Our study demonstrated that the H 2 O 2 -scavenging nano-bionic system could scavenge the abundant ROS in the atherosclerosis lesion, thereby reducing the oxidative stress for treating atherosclerosis and thus achieve the therapeutic goals with atherosclerosis more desirably. H 2 O 2 -scavenging nano-bionic system RPP-PU treated atherosclerosis more effectively by reducing the oxidative state. The sensitivity was close to the lowest concentration of ROS of pathological environment of atherosclerosis. [Display omitted] [ABSTRACT FROM AUTHOR]

The micro-stripe was efficiently transferred by the laser interference-induced forward transfer (LIIFT) technique, composed of Ag nanoparticles (NPs). The effects of the fringe period of the two-beam laser interference on the transferred micro-stripe were discussed. The results showed that the fringe period of the laser interference would affect the particle diameter and spatial distribution of Ag NPs in the micro-stripe transferred. While the fringe period was in the range of 10 to 17 μm, the average diameter of the Ag NPs decreased from 126 to 101 nm with the increase of the period. Moreover, the aggregation of the Ag NPs was improved by increasing the period of the transferred Ag micro-stripe. Finally, the transferred Ag micro-stripe could promote surface-enhanced Raman scattering (SERS). The spectrum intensity of the SERS was significantly enhanced while the transferred Ag micro-stripe was used to the Raman spectrum test of the Rhodamine B (RhB), and the intensity of the Raman spectrum for the RhB was improved with the increase of the Ag NPs micro-stripe period. The results suggested a technique to fabricate the Ag NPs with controllable aggregation efficiently, and further the potential application of the LIIFT technique in the SERS chip of sensitivity detection. [ABSTRACT FROM AUTHOR]

Rapid industrial growth and technological advancements in recent decades have led to an urbanized society at the expense of the environment due to toxic gas emissions. Therefore, it is imperative to detect trace concentrations of harmful gas with reliable techniques. NO 2 is essentially being targeted for detection among all other gases due to its enormous abundance and serious health risks. Recently, 2D-MoS 2 with enormous adsorption sites and high chemical reactivity have been employed selectively to detect NO 2 at room temperature (RT). Herein, uniform and high surface area MoS 2 /In 2 S 3 nanosheets (NSs) heterostructures were synthesized by hydrothermal method. HR-TEM analysis confirmed the 2D/2D heterostructures of MoS 2 /In 2 S 3 nanosheets (NSs), and the increase in surface area of MoS 2 from 10 m2/g to 27.2 m2/g upon addition of In 2 S 3 , measured through BET analysis. The MoS 2 /In 2 S 3 sensor demonstrated excellent sensing capability with a response of 185% towards 50 ppm of NO 2 at RT (30 ℃). Additionally, the sensor exhibited stable detection for about 42 days, repeatability over 5 cycles, and a detection limit of 450 ppb towards NO 2. The synergistic influence of 2D/2D heterostructure with significant active sites and surface area is responsible for the considerable improvement in sensing performance. Therefore, the MoS 2 /In 2 S 3 nanocomposites demonstrate a facile approach for developing high-performance potentially hazardous gas detectors for RT applications. [Display omitted] • MoS 2 /In 2 S 3 composites were prepared via facile hydrothermal method. • MIS-1 exhibits a response of 185% towards 50 ppm of NO 2 at RT. • Good stability (42 days)and limit of detection (35 ppm) shows its excellent gas sensing performance. • The novelty of this work is MoS 2 /In 2 S 3 composite for room temperature NO 2 detection. [ABSTRACT FROM AUTHOR]

Recently, flexible tactile sensors have been widely concerned in many fields, including healthcare monitoring devices and wearable electronics. However, the fabrication of capacitive bionic tactile sensors with a wide linear sensing range and high sensitivity is a major difficulty. A flexible bionic sensor based on the octopus sucker microstructure that improves sensing performance by constructing a biomimetic body with a good microstructure was proposed in this study. The effect of the characteristic parameters of the sensor structure on the sensitivity is studied by simulations and experiments, and the sensor structure is optimized. Experimental results demonstrate that the proposed octopus-inspired tactile sensor has a high sensitivity of 0.636 kPa–1 and a wide linear sensing range (8 Pa-500 kPa). Moreover, the tactile sensor has a rapid response time (∼40 ms), excellent repeatability, and outstanding durability (>6000 cycles), making it a reliable platform for monitoring human movements and bionic manipulator grasping objects. This study provides bionic tactile sensors with significant potential for innovative applications in future intelligent robotics and electronic skins. [ABSTRACT FROM AUTHOR]

Sensitive, flexible, and low false alarm rate X-ray detector is crucial for medical diagnosis, industrial inspection, and scientific research. However, most semiconductors for X-ray detectors are susceptible to interference from ambient light, and their high thickness hinders their application in wearable electronics. Herein, a flexible visible-blind and ultraviolet-blind X-ray detector based on Indium-doped Gallium oxide (Ga 2 O 3 :In) single microwire is prepared. Joint experiment-theory characterizations reveal that the Ga 2 O 3 :In microwire possess a high crystal quality, large band gap, and satisfactory stability, and reliability. On this basis, an extraordinary sensitivity of 5.9 × 10 5  µC Gy air -1  cm -2 and a low detection limit of 67.4 nGy air  s -1 are achieved based on the prepared Ag/Ga 2 O 3 :In/Ag device, which has outstanding operation stability and excellent high temperature stability. Taking advantage of the flexible properties of the single microwire, a portable X-ray detection system is demonstrated that shows the potential to adapt to flexible and lightweight formats. The proposed X-ray detection system enables real-time monitor for X-rays, which can be displayed on the user interface. More importantly, it has excellent resistance to natural light interference, showing a low false alarm rate. This work provides a feasible method for exploring high-performance flexible integrated micro/nano X-ray detection devices., (© 2024 Wiley‐VCH GmbH.)

Background: Viral antigen detection test is the most common method used to detect viruses in the field rapidly. However, due to the low sensitivity, it can only be used as an auxiliary diagnosis method for virus infection. Improving sensitivity is crucial for developing more accurate viral antigen tests. Nano luciferase (Nluc) is a sensitive reporter that has not been used in virus detection. Results: In this study, we produced an intracellularly Nluc labeled detection antibody (Nluc-ch2C5) and evaluated its ability to improve the detection sensitivity of respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens. Compared with the traditional horse-radish peroxidase (HRP) labeled antibody (HRP-ch2C5), Nluc-ch2C5 was 41 times more sensitive for inactivated SARS-CoV-2 virus by sandwich chemiluminescence ELISA. Then we applied Nluc-ch2C5 to establish an automatic magnet chemiluminescence immune assay (AMCA) for the SARS-CoV-2 viral spike protein, the limit of detection was 68 pfu/reaction. The clinical sensitivity and specificity reached 75% (24/32) and 100% (48/48) using 32 PCR-positive and 48 PCR-negative swab samples for clinical evaluation, which is more sensitive than the commercial ELSA kit and colloid gold strip kit. Conclusions: Here, monoclonal antibody ch2C5 served as a model antibody and the SARS-CoV-2 served as a model pathogen. The Nluc labeled detecting antibody (Nluc-ch2C5) significantly improved the detection sensitivity of SARS-CoV-2 antigen. This labeling principle applies to other viral infections, so this labeling and test format could be expected to play an important role in detecting other virus antigens. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrodeposition of gold nanoparticles could increase electrocatalytic activity of glassy carbon electrodes. • Preparation of molecularly imprinted electrochemical sensors by electro-polymerization is feasible. • The imprinted glassy carbon electrode has highly sensitivity and good specific recognition ability for phosmet. • The efficiency of the imprinted sensors is as high as HPLC method. A novel electrochemical sensor MIP/AuNPs/GCE was developed by depositing gold nanoparticles and electropolymerizing molecularly imprinted film on the surface of glassy carbon electrode (GCE) for highly sensitive detection of neutral phosmet residues in fruits and vegetables. Scanning electron microscopy, energy dispersive spectroscopy, atomic force microscopy, cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the imprinted sensor. The results showed that the imprinted film on GCE was evenly prepared with better specific recognition of phosmet on MIP/AuNPs/GCE than that on bare GCE. Several parameters including deposition time, functional monomer and its molar ratio, scanning cycles, and elution time were optimized in detail. The linear range of the MIP/AuNPs/GCE prepared in this work was 0.020–4.0 nmol/L with limit of detection of 0.010 nmol/L, which was much lower than MIP/GCE (0.17 nmol/L). The identification mechanism of MIP/AuNPs/GCE for phosmet was also confirmed as adsorption-diffusion model with effective surface area increasing after mediated by AuNPs. Selectivity, reproducibility and repeatability of the MIP/AuNPs/GCE were acceptable. The recovery of applying the sensor to detect PM in real samples ranged from 91.40 % to 107.3 %, which agreed well with those of HPLC. The method of developing MIP/AuNPs/GCE sensor herein could be extended to detecting other neutral pesticide residues in food and environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • A dual-protecting microemulsion method for 3D pomegranate‐like quantum dot nanobeads with high stability. • A novel AFB1 detection method based on nanobeads has been developed. • The nanobeads improve the fluorescence signal and the sensitivity of detection. • The QBs improve the fluorescence signal and detection sensitivity compared to QD@SiO 2. • This method realized the quantitative detection of AFB1 in corn samples and peanut samples. Aflatoxin B1 (AFB1) is often used as a major indicator for evaluating aflatoxin contamination in food, and its accurate and sensitive detection is of great significance. Herein, the high-quality CdSe/ZnS fluorescent quantum dot nanobeads (QBs) with 3D pomegranate were prepared by the dual-protecting microemulsion method, which showed excellent stability in different environments. AFB1 were detected by competitive quantum dot-based fluorescence-linked immunosorbent assay (QLISA) using 3D pomegranate-like QBs and single-core silica-encapsulated quantum dots (QD@SiO 2). After optimization of the reaction conditions, the quantitative detection range of AFB1 by single-core QD@SiO 2 as fluorescent probe was 0–100 ng/mL, with the half maximal inhibitory concentration (IC50) of 3.01 ng/mL and the limit of detection (LOD) of 0.12 ng/mL; whereas the quantitative detection range of AFB1 by fluorescent QBs was 0–100 ng/mL, with the IC50 of 1.76 ng/mL and the LOD of 1.03 pg/mL. Compared to single-core QD@SiO 2 , the fluorescent QBs was 120-fold more sensitive. The detection of AFB1 was also achieved in negative corn and peanut samples, indicating the possibility of its application to the detection of real food samples. The high performance of competitive QLISA using 3D pomegranate-like QBs as fluorescent probes offer highly sensitive and accurate quantitative detection of analytes in food safety monitoring. [ABSTRACT FROM AUTHOR]

In this paper, we present the design of a compact and highly sensitive microwave sensor based on a metamaterial complementary split-ring resonator (CSRR), for liquid characterization at microwave frequencies. The design consists of a two-port microstrip-fed rectangular patch resonating structure printed on a 20 × 28 mm2 Roger RO3035 substrate with a thickness of 0.75 mm, a relative permittivity of 3.5, and a loss tangent of 0.0015. A CSRR is etched on the ground plane for the purpose of sensor miniaturization. The investigated liquid sample is put in a capillary glass tube lying parallel to the surface of the sensor. The parallel placement of the liquid test tube makes the design twice as efficient as a normal one in terms of sensitivity and Q factor. By bending the proposed structure, further enhancements of the sensor design can be obtained. These changes result in a shift in the resonant frequency and Q factor of the sensor. Hence, we could improve the sensitivity 10-fold compared to the flat structure. Subsequently, two configurations of sensors were designed and tested using CST simulation software, validated using HFSS simulation software, and compared to structures available in the literature, obtaining good agreement. A prototype of the flat configuration was fabricated and experimentally tested. Simulation results were found to be in good agreement with the experiments. The proposed devices exhibit the advantage of exploring multiple rapid and easy measurements using different test tubes, making the measurement faster, easier, and more cost-effective; therefore, the proposed high-sensitivity sensors are ideal candidates for various sensing applications. [ABSTRACT FROM AUTHOR]

We propose and demonstrate a cost-effective liquid refractive index (RI) sensor in polymer materials by employing a Mach-Zehnder interferometer (MZI) formed with the conventional strip waveguide. The proposed sensor can attain high sensitivity by choosing a suitable reference arm length to reduce optical path difference (OPD) between the two arms of the employed MZI. Our fabricated devices, which have the same sensing arm length of 7900 μm but different reference arm lengths of 7900.0, 7942.5, 7950.9, 7962.2, and 7969.5 μm, respectively, exhibit the maximum RI sensitivities of 33662.8 nm/RIU, and almost the same detection range (DR) of 0.0041 ± 0.0002 RIU.

Abstract Background Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, is posing a serious threat to global public health. Reverse transcriptase real-time quantitative polymerase chain reaction (qRT-PCR) is widely used as the gold standard for clinical detection of SARS-CoV-2. Due to technical limitations, the reported positive rates of qRT-PCR assay of throat swab samples vary from 30 to 60%. Therefore, the evaluation of alternative strategies to overcome the limitations of qRT-PCR is required. A previous study reported that one-step nested (OSN)-qRT-PCR revealed better suitability for detecting SARS-CoV-2. However, information on the analytical performance of OSN-qRT-PCR is insufficient. Method In this study, we aimed to analyze OSN-qRT-PCR by comparing it with droplet digital PCR (ddPCR) and qRT-PCR by using a dilution series of SARS-CoV-2 pseudoviral RNA and a quality assessment panel. The clinical performance of OSN-qRT-PCR was also validated and compared with ddPCR and qRT-PCR using specimens from COVID-19 patients. Result The limit of detection (copies/ml) of qRT-PCR, ddPCR, and OSN-qRT-PCR were 520.1 (95% CI: 363.23–1145.69) for ORF1ab and 528.1 (95% CI: 347.7–1248.7) for N, 401.8 (95% CI: 284.8–938.3) for ORF1ab and 336.8 (95% CI: 244.6–792.5) for N, and 194.74 (95% CI: 139.7–430.9) for ORF1ab and 189.1 (95% CI: 130.9–433.9) for N, respectively. Of the 34 clinical samples from COVID-19 patients, the positive rates of OSN-qRT-PCR, ddPCR, and qRT-PCR were 82.35% (28/34), 67.65% (23/34), and 58.82% (20/34), respectively. Conclusion In conclusion, the highly sensitive and specific OSN-qRT-PCR assay is superior to ddPCR and qRT-PCR assays, showing great potential as a technique for detection of SARS-CoV-2 in patients with low viral loads.

Temperature is an important physical parameter and plays a significant role in scientific research, the detection of which cannot be too crucial to study. In order to reduce the interference of the external environment on the detection of temperature and improve the accuracy of the detection results, a multi-parameter detection method using several optical signals was proposed. Here, a novel porous metal–organic framework (MOF), Zn-CYMPN, was synthesized and structurally characterized. Then, fluorescent organic dyes, either DPEE or DPEM, were encapsulated into the pores of Zn-CYMPN independently. The successful synthesis of the composites Zn-CYMPN⊃DPEE or Zn-CYMPN⊃DPEM could easily introduce other fluorescent centers into the original material and made it more convenient to realize multi-parameter temperature detection. More specifically, when the temperature changed, the maximum fluorescent emission wavelength (W) and the maximum optical intensity (I) of the Zn-CYMPN⊃DPEE/DPEM both showed good linear responses with temperature over a wide range, indicating that the composites were highly sensitive thermometers with multi-parameter temperature readouts. In addition, the quantum efficiency and thermal stability of the organic dyes, which bother every researcher, were improved as well.

Recombinase aided amplification (RAA) is an emerging isothermal amplification method used for detecting various pathogens. However, RAA requires a complex and long probe to ensure high sensitivity during fluorescence assay. TaqMan probe used for quantitative PCR (qPCR) is simple and universal. Herein, we developed a new approach for detecting nucleic acids of pathogens, known as RAP (Recombinase aided PCR). The method combines RAA and qPCR to ensure a rapid and highly sensitive detection using a conventional qPCR device. RAP is a two-stage amplification process performed in a single tube within 1 hour. The method involves an RAA reaction for 10 min at 39°C (first stage) followed by 15 cycles of qPCR (second stage). Using human adenovirus 3 (HADV3) and human adenovirus 7 (HADV7) plasmids, the sensitivities of RAP assays for detecting HADV3 and HADV7 were 6 and 17 copies per reaction, respectively. The limit of RAP detection was at least 16-fold lower than the corresponding qPCR, and no-cross reaction with other respiratory viruses was observed. The results of RAP analysis revealed 100% consistency with qPCR assay. This study shows that RAP assay is a rapid, specific, and highly sensitive detection method with a potential for clinical and laboratory application.

Flexible pressure sensors with a broad range and high sensitivity are greatly desired yet challenging to build. Herein, we have successfully fabricated a pressure-temperature dual sensor via an ionic assisted charge enhancement strategy. Benefiting from the immobilization effect for [EMIM + ] [TFSI - ] ion pairs and charge transfer between ionic liquid (IL) and HFMO (H 10 Fe 3 Mo 21 O 51 ), the formed IL-HFMO-TPU pressure sensor shows a high sensitivity of 25.35 kPa -1 and broad sensing range (∼10 MPa), respectively. Furthermore, the sensor device exhibits high durability and stability (5000 cycles@1 MPa). The IL-HFMO-TPU sensor also shows the merit of good temperature sensing properties. Attributed to these superior properties, the proposed sensor device could detect pressure in an ultrawide sensing range (from Pa to MPa), including breathe and biophysical signal monitoring etc. The proposed ionic assisted enhancement approach is a generic strategy for constructing high performance flexible pressure-temperature dual sensor.

The COVID-19 pandemic highlighted the necessity of fast, sensitive, and efficient methods to test large populations for respiratory viruses. The "gold standard" molecular assays for detecting respiratory viruses, such as quantitative polymerase chain reaction (qPCR) and reverse transcription qPCR (RT-qPCR), rely on invasive swab samples and require time-consuming and labor-intensive extraction processes. Moreover, the turnaround time for RT-qPCR-based assays is too lengthy for rapid screening. Extraction-free saliva-based methods provide a non-invasive sampling process with a fast turnaround time and are suitable for high-throughput applications. However, when used with a standard RT-qPCR system, the absence of extraction significantly reduces the assays' sensitivity. Here, using a novel optical modulation biosensing (OMB) platform, we developed a rapid and highly sensitive extraction-free saliva-based molecular assay. We blindly tested 364 paired nasopharyngeal swabs and saliva samples from suspected SARS-CoV-2 cases in Israel. Compared with the gold standard swab-based RT-qPCR assay, the sensitivity of the extraction-free saliva-based OMB assay is 90.7%, much higher than the sensitivity of extraction-free saliva-based RT-qPCR assay (77.8%) with similar specificity (95.3% and 97.6%, respectively). Moreover, out of 12 samples identified by the OMB-based assay as positive, 8 samples were collected from hospitalized patients in a COVID-19 ward and were verified to be SARS-CoV-2-positive upon admission, indicating that the actual clinical sensitivity and specificity of the OMB assay are higher. Considering its user-friendly saliva-based protocol, short and cost-effective extraction-free process, and high clinical accuracy, the OMB-based molecular assay is very suitable for high-throughput testing of large populations for respiratory viruses., Importance: Three years after the SARS-CoV-2 outbreak, there are no molecular tests that combine low-cost and straightforward sample preparation, effective sample handling, minimal reagent and disposable requirements, high sensitivity, and high throughput required for mass screening. Existing rapid molecular techniques typically sacrifice certain requirements to meet others. Yet, localized outbreaks of novel viral diseases happen daily in different parts of the world. In this context, respiratory diseases are of specific importance, as they are frequently airborne and highly contagious, with the potential for a rapid global spread. The widely accepted opinion is that another pandemic is just a question of time. To ensure that the containment efforts for the upcoming "disease X" are successful, introducing rapid, high-throughput, and highly sensitive diagnostic methods for detecting and identifying pathogens is critical. A few months into the pandemic, saliva was suggested as a diagnostic matrix for SARS-CoV-2 detection. The collection of saliva does not require swabs and is minimally invasive. In particular, extraction-free saliva-based assays require fewer reagents and disposables, and therefore are faster and cheaper, offering an appealing alternative for low-income countries. Unfortunately, current extraction-free saliva-based detection methods, such as direct RT-qPCR or isothermal amplification, have either low sensitivity or low throughput. Therefore, we believe that the presented highly sensitive ht-OMBi platform and the extraction-free saliva-based molecular assay can become an essential tool in the infectious disease monitoring toolbox ., Competing Interests: A.D. has a financial interest in MagBiosense, Inc. which, however, did not provide funding for this work

Halide perovskites have shown great potential in X-ray detection due to outstanding optoelectronic properties. However, finding a cost-effective and environmentally sustainable method for handling end-of-life devices has remained challenging. Here, a "One-Click Restart" eco-friendly recycling strategy is introduced for end-of-life perovskite X-ray detectors. This method, utilizing water, allows for the recapture and reuse of both perovskite and conductor materials. The process is straightforward and environmentally friendly, eliminating the need for further chemical treatment, purification, additional additives or catalysts, and complex equipment. A sustainable device cycle is developed by reconstructing flexible perovskite membranes for wearable electronics from recycled materials. Large-scale, flexible membranes made from metal-free perovskite DABCO-N 2 H 5 -I 3 (DABCO = N-N'-diazabicyclo[2.2.2]octonium) achieve remarkably impressive average sensitivity of 6204 ± 268 µC Gy air -1  cm -2 and a low detection limit of 102.3 nGy air s -1 , which makes highly effective for X-ray imaging. The sensitivity of recycled flexible devices not only matches that of single-crystal devices made with fresh materials but also ranks as the highest among all metal-free perovskite X-ray detectors. "One-Click Restart" applies to scalable flexible devices derived from aged single-crystal counterparts, offering significant cost, time, and energy savings compared to their single-crystal equivalents. Such advantages significantly boost future market competitiveness., (© 2024 Wiley‐VCH GmbH.)

As a new rapid additive manufacturing technology that has emerged in recent years, 3D printing technology can realize the precise manufacturing of complex and flexible sensor structures. In this study, a sensor was fabricated by injecting silver nanowires (AgNWs) ethanol solution into stretchable polydimethylsiloxane (PDMS). The substrate was used in two design configurations through a 3D printing template method, i.e. "straight" and "wave". Compared to the straight sensor, the structural design of the wave sensor could increase the stretch range and sensitivity. In particular, the stretch range increased by 26.1% and the sensitivity improved by 96.0%. The stretchable sensor was successfully applied in pronunciation recognition and gait detection. Therefore, the stretchable sensor is also expected to be further used in fields such as foldable phones and wearable physiological signal sensors. [ABSTRACT FROM AUTHOR]

A novel dual band, highly sensitive Substrate Integrated Waveguide (SIW) sensor for permittivity measurements is presented. A pair of modified Complementary Split Ring Resonators (CSRRs) is etched on SIW surface. CSRRs are located in the center of SIW, where the electric field distribution is high so that the coupling be maximized. The coupling between the SIW and the CSRRs as well as the adjacent CSRRs results in two notches in transmission coefficient. These notches vary with the dielectric loading on the sensor. The ratio of a notch variation to the load permittivity variation determines the sensitivity of proposed sensor. Two sensitivities proportional to two notches are provided. Normalized sensitivities from both notches show identical values. Therefore, any environmental effect have the same variation on the TZs. This demonstrates the potential of the proposed sensor for differential operation that can mitigate the effect of environmental condition. The size of the proposed sensor is small as the inductive and the capacitive effects of CSRRs forced the SIW to operate below the cut off frequency at negative-order-resonance mode. All design steps including SIW design, CSRRs design and modified CSRRs effects are presented in details. The sensor operation principle is described through an equivalent circuit model as well as simulation results. The experimental results indicates that the normalized sensitivity is 3.4% which is much higher than similar sensors. The prototype sensor size ($27.8\times 18.4\times 0.508$ mm3) is smaller than those reported in the literature. [ABSTRACT FROM AUTHOR]

A novel magnetic field measurement method based on the magneto-volume effect is proposed. The magnetic field sensing structure fabricated by the proposed measurement method is made by the magnetic fluid (MF) partially filled into the hollow core fiber (HCF). The presence of air provides conditions for the change of MF volume with the magnetic field in the proposed sensing structure. Therefore, the magneto-volume effect is introduced into the magnetic field sensing mechanism. From 109.6 to 125.8 Gs, the peak wavelength shift is −65480 pm and the sensitivity is −4219.15 pm/Gs, which is 28.16 times higher than that of the fabricated contrast sensing structure. The sensitivity of the magnetic field sensing structure is greatly improved by introducing the magneto-volume effect compared with the contrast sensing structure. The response time and recovery time of the sensing structure are equally 0.2 s. Therefore, the sensing structure has high sensitivity, good linearity, and short response time, which has potential application prospects in magnetic field sensing. [ABSTRACT FROM AUTHOR]

Herein, we demonstrated a highly sensitive and ultra-fast photodetector based on nano-CdS thin film synthesized via spray pyrolysis technique. The effect of variations in molar concentration of the sulfur ion sources (thiourea) on the structural and optical properties of the CdS thin films was investigated. The XRD patterns illustrate the hexagonal phase of synthesized CdS thin films with preferred (002)-orientated growth, whereas the film prepared using 0.05 M CdCl2 and 0.03 M of thiourea precursors shows nearly stoichiometric growth of film with lower strain and defect concentration. The band gap of the films was estimated from the optical absorption data which was found to be matching with the standard (2.4 eV) in the above film as compared with other films. A proto-type photodetector device fabricated in the laboratory using optimized CdS thin film shows huge photosensitivity of 104 and ultra-fast response speed of ~ 1.4 ms at 10 V. The results demonstrate the potential of application of nano-CdS thin films for photodetectors and optical switches. [ABSTRACT FROM AUTHOR]

Schematic representation of constructing CS-Fc@SPCE electrochemical immunosensor for the detection of cTnI. [Display omitted] • A label-free electrochemical immunosensor based on ferrocene derivatives amplified signal for cTnI detection was created. • A novel redox-active hybrid material, CS-Fc, which significantly increases the electron transfer rate. • The immunosensor showed excellent analytical performances in the assay of AMI warning biomarker – cTnI. As a biomarker of acute myocardial infarction (AMI), screening for cardiac troponin I (cTnI) has extremely high clinical sensitivity and specificity, and is extremely important for early intervention and risk assessment of AMI. Therefore, a novel redox-active hybrid material, CS-Fc, was synthesized by the Schiff base reaction of chitosan (CS) and ferrocene-carboxylic acid (Fc(COOH)) to form an amide group bonded together, which was used as a substrate-modified material for screen-printed carbon electrode (SPCE), and then assembled with an antibody (Ab), which was constructed into a label-free electrochemical immunosensor for the highly sensitive and rapid detection of cTnI in this study. The redox activity and biocompatibility of the highly stable and conductive composite CS-Fc significantly increased the effective specific surface area, electron transfer rate, and achieved effective amplification and specific analysis of the response signal. Under the optimized experimental conditions, the immunosensor showed a good linear relationship between its response signal and cTnI concentration in the range of 2.44 × 10−2 ∼ 2.50 × 101 ng mL−1, with a limit of detection (LOD) as low as 3.70 × 10−3 ng mL−1 (3σ, n = 11). Meanwhile, when used for the detection of cTnI in actual serum samples, it showed better reproducibility and stability, and the analytical results were better than those of the ELISA method, which indicated that it has a great potential for the accurate and rapid detection of cTnI in serum samples. In addition, it also provides a reliable means and scientific basis for process screening, early warning and prognostic risk assessment of AMI. [ABSTRACT FROM AUTHOR]

Highly sensitive nucleobase sensors offer promising advancements in health and research. This study explores CuO doping's impact on SnSe monolayer adsorption with DNA nucleobases. SnSe–CuO exhibits reduced bandgap and WF compared to Pure SnSe. These alterations signify an augmentation in the material's electron interaction and transport capabilities, consequently amplifying its adsorption prowess for the nucleobases (A: 161 %, C: 112 %, G: 105 %, T: 161 %). Moreover, in-depth analyses of ELF and ED illuminate that nucleobase adsorption on SnSe–CuO primarily entails physical interactions. The investigation extends to EDD and electrostatic potential images, facilitating the identification of electron-rich and electron-depleted regions, thus elucidating the pathways of electron transfer during the adsorption process. In addition, our comparative analysis of E ads for SnSe–CuO monolayers with recent reference articles underscores the exceptional performance of this material. Employing a tailored fitting equation, we establish a robust mathematical relationship between the dielectric constant of solvents and E ads. Lastly, calculations of desorption times for each system reveal that at a temperature of 598 K, all systems manifest desorption times of less than 14 h, highlighting SnSe–CuO's potential as a reusable nucleobase sensor material. This study demonstrates SnSe–CuO monolayers' feasibility in industrial nucleobase sensor applications, offering enhanced sensitivity and versatility. [ABSTRACT FROM AUTHOR]

Gas sensors based on p-type semiconducting metal oxides have recently received significant attention due to their superior gas selectivity compared to those based on n-type metal oxides. Nevertheless, p-type metal oxides-based gas sensors have limitations such as low sensitivity and slow response. Herein, we present highly sensitive and fast responding ethanol (C 2 H 5 OH) gas sensors that are composed of p-type SrTi 1−x Fe x O 3 (STF) with various Fe compositions deposited on vertically aligned SiO 2 nanorods (NRs) with a larger surface-to-volume ratio than STF thin films. As the Fe content increases, the charge transfer energy between adsorbed oxygen species and transition cations decreases, and the amount of oxygen vacancy increases, This results in the acceleration of charge transfer and the generation of active sites. The fabricated STF on SiO 2 NRs exhibited gas responses ranging from 74 to 528 for 50 ppm ethanol gas depending on the Fe content with fast response and recovery time, overcoming the low sensitivity and slow response of previously reported p-type gas sensors. The observed unprecedented synergistic effects of STF on SiO 2 NRs for highly selective ethanol sensing establish a new perspective on quaternary p-type perovskites for selective gas sensing in which n-type metal oxides have been used. • Fast responding to VOCs was achieved by Fe substitution in STO deposited on SiO 2 NRs. • Increased Fe contents in STF has an effect on enhanced ethanol sensing properties. • Enhancement in sensing properties was explained through DFT and XPS analysis. • This work presents new perspectives on p-type perovskite in gas sensing applications. [ABSTRACT FROM AUTHOR]

We propose and demonstrate a cost-effective liquid refractive index (RI) sensor in polymer materials by employing a Mach-Zehnder interferometer (MZI) formed with the conventional strip waveguide. The proposed sensor can attain high sensitivity by choosing a suitable reference arm length to reduce optical path difference (OPD) between the two arms of the employed MZI. Our fabricated devices, which have the same sensing arm length of 7900 µm but different reference arm lengths of 7900.0, 7942.5, 7950.9, 7962.2, and 7969.5 µm, respectively, exhibit the maximum RI sensitivities of 33662.8 nm/RIU, and almost the same detection range (DR) of 0.0041 ± 0.0002 RIU. [ABSTRACT FROM AUTHOR]

In this paper, we present the design of a compact and highly sensitive microwave sensor based on a metamaterial complementary split-ring resonator (CSRR), for liquid characterization at microwave frequencies. The design consists of a two-port microstrip-fed rectangular patch resonating structure printed on a 20 × 28 mm2 Roger RO3035 substrate with a thickness of 0.75 mm, a relative permittivity of 3.5, and a loss tangent of 0.0015. A CSRR is etched on the ground plane for the purpose of sensor miniaturization. The investigated liquid sample is put in a capillary glass tube lying parallel to the surface of the sensor. The parallel placement of the liquid test tube makes the design twice as efficient as a normal one in terms of sensitivity and Q factor. By bending the proposed structure, further enhancements of the sensor design can be obtained. These changes result in a shift in the resonant frequency and Q factor of the sensor. Hence, we could improve the sensitivity 10-fold compared to the flat structure. Subsequently, two configurations of sensors were designed and tested using CST simulation software, validated using HFSS simulation software, and compared to structures available in the literature, obtaining good agreement. A prototype of the flat configuration was fabricated and experimentally tested. Simulation results were found to be in good agreement with the experiments. The proposed devices exhibit the advantage of exploring multiple rapid and easy measurements using different test tubes, making the measurement faster, easier, and more cost-effective; therefore, the proposed high-sensitivity sensors are ideal candidates for various sensing applications.

The fabrication of high performance CuO based glucose sensors remains a great challenge due to the "trade-off effect" between sensitivity and linear range. In this study, a hierarchical CuO nanostructure with a great number of firecracker-shaped nanorods along the ligament and three-dimensional interconnected nanoporous is obtained by dealloying and post oxidation process of Al-33.3 wt% Cu eutectic alloy ribbons. Because of the precise structural design, not only the number of active sites for glucose electro-oxidation is significantly increased but also the glucose diffusion under high concentration is greatly accelerated, leading to a high sensitivity of 1.18 mA cm−2 mM−1 and a wider linear range up to 5.53 mM for glucose detection. This work provides a potential approach to design hierarchical nanostructure for other metal oxides with desirable properties for electrocatalytic applications. [ABSTRACT FROM AUTHOR]

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