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From the perspective of the implementation of China's cross-border e-commerce industrial policy, this study empirically tests the impact of cross-border e-commerce industrial policy on the quality of agricultural products exported by China through using the HS6-digit export data in CEPII-BACI database from 2006 to 2020 and adopting the Difference-in-Difference method. The research shows that the cross-border e-commerce industrial policy has a significant positive impact on the quality of agricultural products exported by China. The study also found that there is significant heterogeneity in the impact on agricultural products exported from different regions and with different quality levels. Finally, the mechanism test conclusion shows that cross-border e-commerce mainly promotes the improvement of export quality of agricultural products exported by China through export competition effect and export learning effect.

Microplastics and nanoplastics are being assumed as emerging toxic pollutants owing to their unique persistent physicochemical attributes, chemical stability, and nonbiodegradable nature. Owing to their possible toxicological impacts (not only on aquatic biota but also on humans), scientific communities are developing innovative technologies to remove microplastics and nanoplastics from polluted waters. Various technologies, including adsorption, coagulation, photocatalysis, bioremediation, and filtration, have been developed and employed to eliminate microplastics and nanoplastics. Recently, adsorption technology has been getting great interest in capturing microplastics and nanoplastics and achieving excellent removal performance. Therefore, this review is designed to discuss recent innovations in developing promising adsorbents for the remediation of microplastics and nanoplastics from wastewater and natural water. The developed adsorbents have been classified into four main classes: sponge/aerogel-based, metal-based, biochar-based, and other developed adsorbents, and their performance efficiencies have been critically examined. Further, the influence of various pertinent factors, including adsorbents' characteristics, microplastics/nanoplastics' characteristics, solution pH, reaction temperature, natural organic matter, and co-existing/interfering ions on the removal performance of advanced adsorbents, have been critically assessed. Importantly, the particle application of the developed adsorbents in removing microplastics and nanoplastics from natural water has been elucidated. In addition, barriers to market penetration of the developed adsorbents are briefly discussed to help experts transfer adsorption-based technology from laboratory-scale to commercial applications. Finally, the current knowledge gaps and future recommendations are highlighted to assist scientific communal for improving adsorption-based technologies to battle against microplastics and nanoplastics pollution.

Raman imaging can effectively characterise microplastics and nanoplastics, which is validated here to capture the items released from the plastic gloves when subjected to a mimicked fire. During the COVID-19 pandemic, large quantities of personal protective equipment (PPE) units have been used, such as the disposable gloves. If discarded and poorly managed, plastics gloves might break down to release secondary contaminants. The breakdown process can be accelerated by burning in a bushfire or at the incineration plants. During the burning process, the functional groups on the surface can be burned differently due to their different thermal stabilities. The different degrees of burning can be distinguished and visualised via Raman imaging. In the meantime, at the bottom of the burned plastics, microplastics and nanoplastics can be generated at a significant amount. The possible false Raman imaging on microplastics and nanoplastics is also discussed, by effectively extracting and distinguishing the weak signal from the background or noise. Overall, these findings confirm the importance of effectively working waste incineration plants and litter prevention, and suggest that Raman imaging is a suitable approach to characterise microplastics and nanoplastics.

Suspended particulate matter (SPM) and sediments are important sources of dissolved organic matter (DOM) in lake water. However, studies on what extent and how both sources affect DOM composition are lacking, which hampers DOM management. Herein, DOM, SPM-extracted particulate organic matter (POM), and sediment-extracted organic matter (SOM) were characterized and compared in terms of absorption spectral properties and chemical composition in Lake Taihu, a large cyanobacterial bloom-affected shallow lake. A statistical method was proposed to quantify the similarity of organic matter (OM) in the different states and to evaluate the potential effects of SPM and sediments on DOM. Results showed that POM and DOM were mainly composed of small-molecular-size and low-humified organic components (i.e., 27 %-38 % tryptophan-like and ~30 % protein-like substances), and most of them were derived from autochthonous sources. While tyrosine-like (57 %) and humic-like (27 %) substances were dominant in SOM. The OM similarity between POM and DOM was approximately 1.5 times higher than that between SOM and DOM, indicating the greater effect of SPM than sediments on DOM composition. High pH and low nitrogen (e.g., nitrate and ammonia) were positively correlated to the OM similarity between POM and DOM. Further, the findings indicated that nitrogen limitation enhanced the OM exchange between POM and DOM by promoting the production of extracellular polymeric substances (EPS) in cyanobacterial aggregates. The obtained findings highlighted the importance of SPM in shaping the DOM composition relative to sediments and facilitating the DOM management in bloom-affected lakes.

Raman spectroscopy is a powerful technique for the study of materials chemistry and nanostructure. This nondestructive technique is highly sensitive to molecular and crystal lattice vibrations, whi...

A compact microfluidic Raman detection system based on a single-ring negative-curvature hollow-core fiber is presented. The system can be used for in-line qualitative and quantitative analysis of biochemicals. Both efficient light coupling and continuous liquid injection into the hollow-core fiber were achieved by creating a small gap between a solid-core fiber and the hollow-core fiber, which were fixed within a low-cost ceramic ferrule. A coupling efficiency of over 50% from free-space excitation laser to the hollow core fiber was obtained through a 350 μm-long solid-core fiber. For proof-of-concept demonstration of bioprocessing monitoring, a series of ethanol and glucose aqueous solutions at different concentrations were used. The limit of detection achieved for the ethanol solutions with our system was ~0.04 vol.% (0.32 g/L). Such an all-fiber microfluidic device is robust, provides Raman measurements with high repeatability and reusability, and is particularly suitable for the in-line monitoring of bioprocesses.

Metal nanostructures, e.g., nanohole arrays, have attracted a large amount of interests due to their extraordinary properties and potential to boost light-matter interactions in the subwavelength scale. Optical fibers offer a portable and accessible platform to propose novel devices. However, patterning of metal nanohole arrays on optical fibers always requires complicated techniques or adhesion layers, which leads to an expensive, time-comsuming fabrication procedure or potential contaminations inside the nanoholes, therefore a degraded performance. Herein, we report a novel route to propose fiber-based plasmonic devices by directly transferring a gold nanohole array onto the endface of a multi-mode fiber. A replication-releasing method is applied to achieve the high-troughout transfer and integration. As a potential application, sensing with aqueous media is highlighted. These findings pave a new way to propose plasmonic devices for wider scopes of applications across the nanophotonics.

Metal-halide perovskites have emerged as one of the most promising semiconductor materials for photovoltaic and other optoelectronic applications. Recently, mixed halide hybrid perovskites where I− is partly substituted by Br− have driven a paradigm shift in perovskite solar cells, combining tunability of absorption onset with high performance. However, poor long-term device stability has been limiting their practical application and the mechanisms of degradation have not been fully understood. In this work, we study light induced degradation in mixed halide perovskite CH3NH3PbI3−xBrx. Although it is well-known that such perovskites undergo a reversible light-induced phase segregation, the subsequent degradation process under continued, and in particular high intensity laser irradiation has not been systematically studied. By utilizing in situ laser excited photoluminescence spectroscopy it is shown that such mixed halide perovskites degrade via light-induced degradation of the I-rich domain after this initial phase segregation. Significantly, the oxygen sensitivity of the I-rich domain is identified as a key factor to inducing this irreversible decomposition as supported by in situ Raman spectroscopy. Our work provides insight into the degradation of mixed-halide perovskites under high light intensities and direction for the development and processing of compositionally and environmentally stable perovskite materials.

Formaldehyde (FA) is widely applied as a fixative for proteins such as collagen. Current studies have confirmed that the reversible oligomer-to-monomer equilibrium of FA in aqueous solution and the proportion of FA monomer is a significant factor affecting tissue fixation. Since the hydrolysis of FA oligomers is a dynamic process affected jointly by different factors, its real time monitoring has proved to be challenging. In this work, by utilizing the well-established Raman technique as an analytical platform, we identified the factors affecting the hydrolysis of FA oligomers by rationally examining the νs (OCO) and νas (OCO) modes with varying conditions, such as time, pH, temperature, and FA concentration. The optimized conditions of the highest hydrolysis rate of oligomers into monomers for fixation on collagen and tissues have been found to be relatively low FA concentration (≤5%) in phosphate-buffered saline at pH 9.0 in room temperature. In order to compare the fixation quality of the optimized conditions to that of the conventional conditions used by current medical practices (4% FA concentration in tap water under room temperature), Raman spectroscopy and chemical derivatization methods with o-phthalaldehyde and fluorescent probe FAP-1 have been investigated, and our results revealed that the FA molecules under our optimized conditions have reacted with at least 15% more amino groups within collagen compared to those under the conventional conditions mentioned above. This study provides direct evidence of the FA equilibrium in solution by Raman spectroscopy, which could be applied for the optimal use of FA in medicine, even at an industrial scale.

Nanoparticles with specific properties and functions have been developed for various biomedical research applications, such as in vivo and in vitro sensors, imaging agents and delivery vehicles of therapeutics. The development of an effective delivery method of nanoparticles into the intracellular environment is challenging and success in this endeavor would be beneficial to many biological studies. Here, the well-established microelectrophoresis technique was applied for the first time to deliver nanoparticles into living cells. An optimal protocol was explored to prepare semiconductive quantum dots suspensions having high monodispersity with average hydrodynamic diameter of 13.2-35.0 nm. Micropipettes were fabricated to have inner tip diameters of approximately 200 nm that are larger than quantum dots for ejection but less than 500 nm to minimize damage to the cell membrane. We demonstrated the successful delivery of quantum dots via small electrical currents (-0.2 nA) through micropipettes into the cytoplasm of living human embryonic kidney cells (roughly 20-30 μm in length) using microelectrophoresis technique. This method is promising as a simple and general strategy for delivering a variety of nanoparticles into the cellular environment.

Nanoparticles with desirable properties and functions have been actively developed for various bio-medical research, such as in vivo and in vitro sensors, imaging agents and delivery vehicles of therapeutics. However, an effective method to deliver nanoparticles into the intracellular environment is a major challenge and critical to many biological studies. Current techniques, such as intracellular uptake, electroporation and microinjection, each have their own set of benefits and associated limitations (e.g., aggregation and endosomal degradation of nanoparticles, high cell mortality and low throughput). Here, the well-established microelectrophoresis technique is applied for the first time to deliver nanoparticles into target cells, which overcomes some of these delivery difficulties. Semiconductive quantum dots, with average hydrodynamic diameter of 24.4 nm, have been successfully ejected via small electrical currents (−0.2 nA) through fine-tipped glass micropipettes as an example, into living human embryonic kidney cells (roughly 20 - 30μm in length). As proposed by previous studies, micropipettes were fabricated to have an average tip inner diameter of 206 nm for ejection but less than 500 nm to minimize the cell membrane damage and cell distortion. In addition, delivered quantum dots were found to stay monodispersed within the cells for approximately one hour. We believe that microelectrophoresis technique may serve as a simple and general strategy for delivering a variety of nanoparticles intracellularly in various biological systems.

We demonstrate a plasmonic fiber tip for relative humidity (RH) detection by integrating a gold nanomembrane onto the end-face of a multimode optical fiber via a flexible and high-efficiency transfer method. Fast water condensation/evaporation is responsible for the high performance of the fiber tip in response to RH. A high sensitivity of 279 pm/%RH is obtained in the range of 11 % ∼ 92 % R H . Taking advantage of the fast dynamics (response and recovery times of 156 ms and 277 ms), the plasmonic fiber tip offers an excellent detection capability to human breaths at varied frequencies and depths. The compact, easy-fabrication, and fast-dynamics plasmonic platform has versatile potential for practical applications, including environmental and healthcare monitoring, as well as biochemical sensing.

The development of amorphous films with a wide transmission window and high refractive index is of growing significance due to the strong demand of integrating functional nanoparticles for the next-generation hybrid optoelectronic films. High-index TeO2-based glass films made via the sol–gel process are particularly suitable as their low temperature preparation process promises high compatibility with a large variety of nanoparticles and substrates that suffer from low thermal stability. However, due to the lack of in-depth understanding of the mechanisms of the formation of undesired metallic-Te (highly absorbing species) in the films, the preparation of high-transmission TeO2-based sol–gel films has been severely hampered. Here, by gaining insight into the mechanistic chemistry of metallic-Te formation at different stages during the non-hydrolytic sol–gel process, we identify the chemical route to prevent the generation of metallic-Te in a TeO2-based film. The as-prepared TeO2-based film exhibits a high transmission that is close to the theoretical limit. This opens up a new avenue for advancing the performance of hybrid optoelectronic films via incorporating a large variety of unique nanoparticles. Refereed/Peer-reviewed

Nitric oxide plays a crucial role as a messenger in biological systems, but limitations in measurement are restricted due to its relatively low concentration and short half-life time. Here we report a novel approach to sensing nitric oxide by using an exposed core fiber with its core coated with CdTe/CdS core/shell quantum dots.This enables rapid detection and opens up the possibility of monitoring its production within biological systems.The detection mechanism is based on fluorescence quenching of CdTe/CdS quantum dots by nitric oxide, which can coordinate with Cd²⁺ directly as a ligand forming transition metal complexes. We demonstrate that CdTe/CdS quantum dots functionlization exposed core optical fibers can respond rapidly to nitric oxide in physiologicalenvironments with picomolar sensitivity. Refereed/Peer-reviewed

A mercury optical fiber dip sensor was developed by immobilizing Rhod-5N on a multimode fiber endface by silica sol-gel. The detection limit was 0.3 ppb with the dye in aqueous condition and 25 ppb when it was immobilized on fiber tips.

Highly fluorescent perovskite materials have attracted considerable interest for fundamental research and potential applications. In this work, we demonstrate the recoverable PL quenching of methylammonium lead halides (MAPbX3, where X is Cl, Br or I) upon exposure to gaseous ammonia that enables the use of hybrid perovskites in gas-sensing applications. XRD analysis confirmed that the MA cations in the perovskite material were replaced by NH3 to form NH4PbX3·MA, thereby resulting in distinct changes in the crystalline structure and, consequently, PL quenching. However, as a weak coordination complex, NH4PbX3·MA can be easily thermally decomposed to recover the starting product MAPbX3 with the release of ammonia. An in-depth understanding of the reversible chemical and structural changes of the perovskites by exposing them to polar molecules such as ammonia can advance the development of hybrid perovskite sensors and provides insights into the mechanisms of how perovskites coordinate with polar molecules.

An extraordinary optical transmission fibre-optic surface plasmon resonance biosensing platform was engineered to improve its portability and sensitivity, and was applied to monitor the concentrations of monoclonal antibodies (Mabs). By refining the fabricating procedure and changing the material of the flow cell and the components of the optical fibre, the biosensor is portable and robust to external interference. After the implementation of an effective template cleaning procedure and precise control during the fabrication process, a consistent sensitivity of 509 ± 5 nm per refractive index unit (nm/RIU) was achieved. The biosensor can detect the Mab with a limit of detection (LOD) of 0.44 µg/mL. The results show that the biosensor is a potential tool for the rapid quantification of Mab titers. The biosensor can be regenerated at least 10 times with 10 mM glycine (pH = 2.5), and consistent signal changes were obtained after regeneration. Moreover, the employment of a spacer arm SM(PEG)2, used for immobilising protein A onto the gold film, was demonstrated to be unable to improve the detecting sensitivity, thus, a simple procedure without the spacer arm could be used to prepare the protein A-based biosensor. Our results demonstrate that the fibre-optic surface plasmon resonance biosensor is competent for the real-time and on-line monitoring of antibody titers in the future as a process analytical technologies (PATs) tool for bioprocess developments and the manufacture of therapeutic antibodies.

In this study, a specifically-designed aggregation-induced emission fluorogen (AIEgen) with nanoparticle aggregates was used to quantitatively evaluate the bioaccumulation of Hg2+ and visualize Hg2+ kinetics in vivo within the rotifer Brachionus plicatilis for the first time. Quantitative results showed that a sharp drop in Hg2+ concentration occurred at the very beginning in the medium containing rotifers and Hg2+, showing a quick initial uptake of Hg2+ by the rotifers, and then the concentration in the medium plateaued after 5 min. With an increase in rotifer density, the amount of bioaccumulation increased in the rotifer. However, the bioaccumulation efficiency of Hg2+ decreased from 5.28 μg mg−1 h−1 at a low rotifer density of 0.093 mg ml−1 to 2.61 μg mg−1 h−1 at a high rotifer density of 0.375 mg mL−1. Moreover, the fluorescence images and spectra results illustrate that the ingestion of Hg2+ by the rotifer was via its mouth surrounded by the ciliary corona to the digestive tract, and Hg2+ could not permeate into the body integument through diffusion during the study period. Hg2+-induced fluorescence in rotifers dissipated in 6 h after staining, possibly through defecation and excretion. This study indicates that inorganic mercury can be quickly ingested by a rotifer via feeding, but is unlikely deposited as methylated mercury in rotifer tissues.

This paper presents a study of propagation of radially and azimuthally polarized cylindrical vector modes in six-strut suspended core fibers based on finite element simulations. The study shows that large effective index differences in the order of $10^{-3}- 10^{-2}$ of these modes can be achieved in the suspended core fibers with core diameter of less than 2 μ m, material index 1.45 of silica to 2.0 of tellurite, and wavelength of 750 nm, allowing the stable propagation of the first higher order modes in doughnut shape within these fibers. The effective index difference and the field intensity of these cylindrical vector modes can be tuned by selecting appropriate fiber material and core size. The study shows that the suspended core fiber can be a competitive candidate for fiber-based high-resolution stimulated emission depletion nanoscopy application.

We demonstrate that the δ to α phase transition temperature of formamidinium-based perovskites is reduced by ∼50 °C through the incorporation of ∼2 wt% γ-butyrolactone (GBL) into the crystal lattice. The intercalation of GBL is found to expand the unit cell of the δ-phase, reducing the energy barrier for thermal conversion.

Micro-cyanobacteria and pico-cyanobacteria coexist in many lakes throughout the world. Their distinct cell sizes and nutrient utilization strategies may lead to dominance of one over the other at varying nutrient levels. In this study, Microcystis aeruginosa and Synechococcus sp. were chosen as representative organisms of micro- and pico-cyanobacteria, respectively. A series of nitrate and ammonia conditions (0.02, 0.1, 0.5, and 2.5 mg N L−1) were designed in mono- or co-cultured systems, respectively. Growth rates of the two species were calculated and fitted by the Monod and Logistic equations. Furthermore, the interspecific competition was analyzed using the Lotka–Volterra model. In mono-cultures, the two cyanobacteria displayed faster growth rates in ammonia than in nitrate. Meanwhile, Synechococcus sp. showed faster growth rates compared to M. aeruginosa in lower N groups (≤ 0.5 mg N L−1). However, in the highest nitrate treatment (2.5 mg N L−1), M. aeruginosa achieved much higher biomass and faster growth rates than Synechococcus sp.. In co-cultures, Synechococcus sp. dominated in the lowest N treatment (0.02 mg N L−1), but M. aeruginosa dominated under the highest nitrate condition (2.5 mg N L−1). Based on the analysis of Raman spectra of living cells in mono-cultures, nitrate (2.5 mg N L−1) upgraded the pigmentary contents of M. aeruginosa better than ammonia (2.5 mg N L−1), but nitrogen in different forms showed little effects on the pigments of Synechococcus sp.. Findings from this study can provide valuable information to predict cyanobacterial community succession and aquatic ecosystem stability.

The high refractive index of heavy metal oxide glasses combined with their low processing temperatures enables new fiber concepts such as enhanced imaging core density, stable doughnut beam delivery, miniaturized imaging+sensing and intrinsic magnetic sensitivity.

Fluorescence images approaching sub-micron resolution are formed in thin nanocrystalline phosphor films. The images are created with UV exposure of the films under chrome-coated quartz masks. The UV light locally changes the valence state of the samarium ions in the nanocrystalline phosphors to activate fluorescence properties. The red fluorescence images are then read-out with blue-violet light. With an imaging resolution approaching the diffraction limit, this technology has potential for anti-counterfeiting labelling or optical data storage applications Refereed/Peer-reviewed

An AIE-active polytriazole coated fibre tip sensor was developed to detect picric acid with its detection limit down to 100 ppb. The fibre sensor requires an analysis time of only a few minutes and shows strong photostability and high reusability, and is promising for remote sensing of explosives in dangerous environments.

Plasmonic devices using periodic metallic nanostructures have recently gained tremendous interest for color filters, sensing, surface enhanced spectroscopy, and enhanced photoluminescence, etc. However, the performance of such plasmonic devices is severely hampered by the solid substrates supporting the metallic nanostructures. Here, a strategy for freestanding metallic nanomembranes is introduced by taking advantages of hollow substrate structures. Large-area and highly uniform gold nanomembranes with nanohole array are fabricated via a flexible and simple replication-releasing method. The hollow structures include a hollow core fiber with 30 μm core diameter and two ferrules with their hole diameter as 125 and 500 μm, respectively. As a proof-of-concept demonstration, 2 times higher sensitivity of the bulk refractive index is obtained with this platform compared to that of a counterpart on a solid silica substrate. Such a portable and compact configuration provides unique opportunities to explore the intrinsic properties of the metal nanomembranes and paves a new way to fabricate high-performance plasmonic devices for biomolecule sensing and color filter.

Plasmonic nanostructures have found widespread applications in nanophotonics, photochemistry and optoelectronics, and chemical sensing is one of their most vibrant applications. However, it still remains open to achieve selective detections with plasmonic nanostructures, especially, at room temperature. Polymers have been attractive as vapor sensitive materials as their electrical and optical properties vary with exposure to vapors at room temperature. MoS2, as an emerging 2D material, has facilitated chemical sensing due to its stability, ultrahigh surface-to-volume ratio, and various attractive sites for analyte molecule adsorptions, including sulfur defect, vacancy, and edge sites. The combination of both MoS2 and polymers with plasmonic has great potential to enable high performance gas sensing at room temperature. Here, a selective detection towards methanol vapors is demonstrated using an epoxy as a sensitive polymer material to bond methanol molecules via both hydrogen atoms and the lone electron pairs on the hydroxyl group. Using a MoS2 monolayer coating, improved sensing response and selectivity towards small-size vapors, especially oxygen-functionalized methanol, are observed because of selective filtration effect. In addition, this plasmonic sensor is insensitive to relative humidity variation in the range of 11 %RH to 92 %RH as well as stable over a long-term period of one year, which demonstrates the high potential of the sensor for practical applications. These findings pave the way for a generic strategy to design selective and sensitive gas sensors via the combination of selectivity-enabling polymer, sensitivity-enhancing 2D materials and signal-transducing plasmonic nanostructures.

Macroporous bovine serum albumin (BSA) nanoparticles with controllable diameter were readily fabricated in a rapidly rotating angled glass tube in a vortex fluidic device (VFD). Systematically varying the rotational speed and the ratio of BSA, ethanol, and glutaraldehyde led to conditions for generating ca. 600 nm diameter macroporous particles that have intrinsic fluorescence emission at 520 nm when excited at 490 nm. The presence of the macropores increased the absorption efficiency of rhodamine B with potential applications for drug delivery purpose, compared with BSA nanoparticles having surfaces devoid of pores. Further control over the size of BSA nanoparticles occurred in the presence of C-phycocyanin protein during the VFD processing, along with control of their shape, from spheres to pockets, as established in exploring the parameter space of the microfluidic device.

We report fabrication and simulation of an F2 glass six-strut suspended core fiber (SCF) with small effective core diameter of 2.5 mu m for cylindrical vector (CV) modes generation and propagation. Simulation results show that the fiber has a large effective refractive index difference in the order of 10(-4)-10(-3) between the first higher-order CV modes. including TE01, HE21 (even and odd )and TM01 modes. TE01 and TM01 were experimentally generated and were evaluated as having high purity of 82 percent and 85 percent. respectively. The results demonstrate that the SCF is a competitive waveguide candidate for selectable CV mode generation and propagation. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement Refereed/Peer-reviewed

In this paper, a novel and efficient approach to digital optical data storage using rare-earth ion doped inorganic insulators is demonstrated. More specifically, the nanocrystalline alkaline earth halide BaFCl: Sm is shown to hold great potential for multilevel optical data storage. Proof-of-concept demonstrations show that these phosphors could be used for rewritable, multilevel optical data storage down to the physical dimensions of a single nanocrystal. Multilevel information storage is based on the highly-efficient and reversible conversion of Sm3+ to Sm2+ ions upon exposure to UV-C light. The stored information is efficiently read-out by employing the photoluminescence of the Sm2+ ions in the nanocrystals, with the signal strength being dependent on the UV-C intensity used during the write step. This serves as the mechanism for multilevel data storage in the individual nanocrystals. This data storage platform has the potential to be extended to 2D and 3D memory for storage densities that could approach tera- or even petabyte/cm(3) levels. Refereed/Peer-reviewed

Traditional optical fibers are insensitive to magnetic fields, however many applications would benefit from fiber-based magnetometry devices. In this work, we demonstrate a magnetically sensitive optical fiber by doping nanodiamonds containing nitrogen vacancy centers into tellurite glass fibers. The fabrication process provides a robust and isolated sensing platform as the magnetic sensors are fixed in the tellurite glass matrix. Using optically detected magnetic resonance from the doped nanodiamonds, we demonstrate detection of local magnetic fields via side excitation and longitudinal collection. This is a first step towards intrinsically magneto-sensitive fiber devices with future applications in medical magneto-endoscopy and remote mineral exploration sensing.

Over recent decades, aggregation-induced emission (AIE) molecules have attracted increasing attention. Restriction of intramolecular rotation (RIR) has been widely accepted as the cause of the emission when AIE molecules aggregate into clusters. The intramolecular rotation of AIE molecules can be monitored by molecular vibration spectra such as nuclear magnetic resonance (NMR), infrared, and Raman, especially surface-enhanced Raman scattering (SERS) which has high sensitivity down to a single molecule. We employed SERS and NMR to study the AIE emission mechanism and compared experimental results with simulation data to monitor the RIR. Interestingly, we found that intramolecular rotation was also restricted for individual AIE molecules loaded onto SERS substrate surfaces due to the laid-down configuration.

A single-ended ultra-thin spherical microbubble fabrication method based on the pressure-assisted arc discharge was developed. The thickness of microbubble could be reached to 2 microns. Its deformation sensitivity was about 22pm/kPa and 10pm/kPa at different pressures. The Q value was 10e7.

Morus alba L. (family Moreaceae), also known as white mulberry, is distinguished as a source of highly promising traditional medicines (including Mori Folium, Mori Fructus, Mori Ramulus and Mori Cortex) and also functional foods. Over the past two decades, the vast majority of the studies with regard to the isolation and bioactivities of M. alba polysaccharides have mainly focused on its leaves and fruits, which are both medicinal and edible. The tender M. alba leaf is edible and can be used to make tea, the mature M. alba fruit is sweet and juicy. M. alba fruits and leaves contain rich bioactive polysaccharides, which are shown to possess various promising bioactivities, mainly including antidiabetic, immunomodulation, anti-inflammation, antioxidation, anti-obesity, hepatoprotection and renoprotection. The main purpose of this review is to provide systematically reorganized information on structural characteristics and bioactivities of M. alba polysaccharides to support their further therapeutic potentials and sanitarian functions.

In this paper, an egg-shaped microbubble is proposed and analyzed firstly, which is fabricated by the pressure-assisted arc discharge technique. By tailoring the arc parameters and the position of glass tube during the fabrication process, the thinnest wall of the fabricated microbubble could reach to the level of 873nm. Then, the fiber Fabry-Perot interference technique is used to analyze the deformation of microbubble that under different filling pressures. It is found that the endface of micro-bubble occurs compression when the inner pressure increasing from 4Kpa to 1400KPa. And the pressure sensitivity of such egg-shaped microbubble sample is14.3pm/Kpa. Results of this study could be good reference for developing new pressure sensors, etc.

We present results demonstrating the prospects of samarium-doped nanocrystals for use in ultra-high capacity multilevel optical data storage. Optical data storage is demonstrated through fluorescence tuning of MeFCl:Sm (Me: Ba, Sr) in the deep UV with a 7 orders of magnitude linear dynamic range.

Bobo Du, Yuan Yang, Yang Zhang, Peipei Jia, Heike Ebendorff-Heidepriem, Yinlan Ruan, and Dexing Yang

We prepared the isolated micrometer-sized diamond particles without seeding on the substrate in hot filament chemical vapor deposition. The diamond particles with specific crystallographic planes and strong silicon-vacancy (SiV) photoluminescence (PL) have been prepared by adjusting the growth pressure. As the growth pressure increases from 2.5 to 3.5 kPa, the diamond particles transit from composite planes of {100} and {111} to only smooth {111} planes. The {111}-faceted diamond particles present better crystal quality and stronger normalized intensity of SiV PL with a narrower bandwidth of 5 nm. Raman depth profiles show that the SiV centers are more likely to be formed on the near-surface areas of the diamond particles, which have poorer crystal quality and greater lattice stress than the inner areas. Complex lattice stress environment in the near-surface areas broadens the bandwidth of SiV PL peak. These results provide a feasible method to prepare diamond particles with specific crystallographic planes and stronger SiV PL.

Integration of conductive materials into optical fibres can largely expand functions of fibre devices including surface plasmon resonator/metamaterial, modulators/detectors, or biosensors. Some early attempts have been made to incorporate metals such as tin into fibres during the fibre drawing process. Due to the restricted range of materials that have compatible melting temperatures with that of silica glass, the methods to incorporate metals along the length of the fibres are very challenging. Moreover, metals are nontransparent with strong light absorption, which causes high fibre loss. This article demonstrates a novel but simple method for creating transparent conductive reduced graphene oxide film onto microstructured silica fibres for potential optoelectronic applications. The strongly confined evanescent field of the suspended core fibres with only 2 μW average power was creatively used to transform graphene oxide into reduced graphene oxide with negligible additional loss. Existence of reduced graphene oxide was confirmed by their characteristic Raman signals, shifting of their fluorescence peaks as well as largely decreased resistance of the bulk GO film after laser beam exposure.

A nitric oxide fiber dip sensor was developed by immobilizing ruthenium(II) complex on multimode fiber tip using silica sol-gel. The emitted fluorescence from fiber NO sensor showed linear dependence on NO concentration below 60mM.

Novel approaches for digital data storage are imperative, as storage capacities are drastically being outpaced by the exponential growth in data generation. Optical data storage represents the most promising alternative to traditional magnetic and solid-state data storage. In this paper, a novel and energy efficient approach to optical data storage using rare-earth ion doped inorganic insulators is demonstrated. In particular, the nanocrystalline alkaline earth halide BaFCl:Sm is shown to provide great potential for multilevel optical data storage. Proof-of-concept demonstrations reveal for the first time that these phosphors could be used for rewritable, multilevel optical data storage on the physical dimensions of a single nanocrystal. Multilevel information storage is based on the very efficient and reversible conversion of Sm³⁺ to Sm²⁺ ions upon exposure to UV-C light. The stored information is then read-out using confocal optics by employing the photoluminescence of the Sm²⁺ ions in the nanocrystals, with the signal strength depending on the UV-C fluence used during the write step. The latter serves as the mechanism for multilevel data storage in the individual nanocrystals, as demonstrated in this paper. This data storage platform has the potential to be extended to 2D and 3D memory for storage densities that could potentially approach petabyte/cm³ levels. Refereed/Peer-reviewed