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As one of the major causes of antimicrobial resistance, beta-lactamase develops rapidly among bacteria. Detection of beta-lactamase in an efficient and low-cost point-of-care testing (POCT) way is urgently needed. However, due to the volatile environmental factors, the quantitative measurement of current POCT is often inaccurate. Herein, we demonstrate an artificial intelligence (AI)-assisted mobile health system that consists of a paper-based beta-lactamase fluorogenic probe analytical device and a smartphone-based AI cloud. An ultrafast broad-spectrum fluorogenic probe (B1) that could respond to beta-lactamase within 20 s was first synthesized, and the detection limit was determined to be 0.13 nmol/L. Meanwhile, a three-dimensional microfluidic paper-based analytical device was fabricated for integration of B1. Also, a smartphone-based AI cloud was developed to correct errors automatically and output results intelligently. This smart system could calibrate the temperature and pH in the beta-lactamase level detection in complex samples and mice infected with various bacteria, which shows the problem-solving ability in interdisciplinary research, and demonstrates potential clinical benefits., Funding Agencies|National Key R&D Program of China [2020YFA0709900]; National Natural Science Foundation of China [62288102, 22077101, 52073230]; Joint Research Funds of Department of Science & Technology of Shaanxi Province; Northwestern~Polytechnical University [2020GXLH-Z-008, 2020GXLH-Z-013]; Shaanxi Provincial Science Fund for Distinguished Young Scholars [2023-JC-JQ-32]; Key Research and Development Program of Shaanxi [2020ZDLGY13-04]; Fundamental Research Funds for the Central Universities and Innovation Foundation for Doctorate Dissertation of Northwestern Polytechnical University [CX2021121]

Integrating imaging and therapeutic capabilities into a single entity can offer enhanced diagnostic accuracy and treatment efficacy in clinically effective formulations. Due to the diversity of chemical structures and/or limited solubility of inhibitors or fluorophores, it is essential to employ a robust delivery carrier that can facilitate drug absorption and distribution during its circulation in the blood. This study explores the potential of hollow gadolinium oxide (Gd2O3) nanocarriers in imaging and drug delivery applications. The citric acid (CA)-capped hollow gadolinium oxide nanocarriers were synthesized via urea-assisted precipitation and hydrothermal methods using carbon spheres as sacrificial templates. The resulting nanosized hollow spheres displayed a spherical morphology and demonstrated relaxation rates in the longitudinal and transverse directions, as indicated by their r 1 and r(2) values of 1.8 and 5.3 s(-1) mM(-1), respectively. To mimic the physiological conditions, the hollow gadolinium oxide spheres were loaded separately with antibiotic sparfloxacin and the azo dye Congo red at neutral pH (7.4) and body temperature (37 degrees C). The CR-loaded nanospheres exhibited a time-dependent internalization behavior with HeLa cells, suggesting their imaging potential for intracellular drug delivery. Furthermore, the SP-loaded nanospheres demonstrated antimicrobial activity against both Gram-positive and Gram-negative bacteria, demonstrating their therapeutic potential against bacterial infections. To mitigate the risk of leaching of Gd3+ ions and their inherent toxicity, a CA coating was applied to hollow gadolinium oxide surface which resulted in outstanding cell viability of the surface functionalized nanocarriers. In addition, the CA coating offered additional support for the increased encapsulation and continuous release of drug molecules until 1 week (168 h). The characterization data provide evidence for the potential of CA-capped hollow gadolini, Funding Agencies|Deutscher Akademischer Austauschdienst; University of Cologne within the framework of UoC-Forum; Advanced Concepts for Therapy and Diagnostic; German Academic Exchange Service (DAAD)

Intracellular viscosity plays an important role in regulating cellular morphology and physiology and is closely related to a host of diseases. Especially, the changes in mitochondrial viscosity will cause some common diseases such as hyperlipidemia, Alzheimer's disease and cancer. In this work, we report the design of a red-emissive molecular rotor for the detection of mitochondrial viscosity in live cells. The probe showed fascinating performance, such as specific targeting to mitochondria, high sensitivity to viscosity, and rapid fluorescence response, especially the dual response mode of fluorescence intensity and fluorescence lifetime. By using this probe, we realized monitoring of the mitochondrial viscosity variations in live cells under different physiological processes. Our study offers an opportunity to discover potential tools for mitochondria-related physiology and pathology investigation. A D-pi-A typed fluorescence lifetime probe for sensitively detecting viscosity has been designed and synthesized. BSOH has been successfully applied to real-time monitoring mitochondrial viscosity in live cells by fluorescence lifetime imaging., Funding Agencies|National Natural Science Foundation of China [22104001, 22074001, 22174001, 22134001]; National Natural Science Foundation of China [2023qd23, 2023qd26]; Scientific Research Startup Funding of Chuzhou University

Temperature homeostasis is critical for cells to perform their physiological functions. Among the diverse methods for temperature detection, fluorescent temperature probes stand out as a proven and effective tool, especially for monitoring temperature in cells and suborganelles, with a specific emphasis on mitochondria. The utilization of these probes provides a new opportunity to enhance our understanding of the mechanisms and interconnections underlying various physiological activities related to temperature homeostasis. However, the complexity and variability of cells and suborganelles necessitate fluorescent temperature probes with high resolution and sensitivity. To meet the demanding requirements for intracellular/subcellular temperature detection, several strategies have been developed, offering a range of options to address this challenge. This review examines four fundamental temperature-response strategies employed by small molecule and polymer probes, including intramolecular rotation, polarity sensitivity, Forster resonance energy transfer, and structural changes. The primary emphasis was placed on elucidating molecular design and biological applications specific to each type of probe. Furthermore, this review provides an insightful discussion on factors that may affect fluorescent thermometry, providing valuable perspectives for future development in the field. Finally, the review concludes by presenting cutting-edge response strategies and research insights for mitigating biases in temperature sensing. In this review, we primarily summarized four temperature-response strategies. Then, we further analyzed the chemical modifications and biological applications of the probes. Finally, we have provided a prospective on the future development of probes., Funding Agencies|National Natural Science Foundation of China [22077101]; CPSF [GZB20230379]; China Postdoctoral Science Foundation [2023M742919]; XMU; Fundamental Research Funds for the Central Universities; STINT Joint China-Sweden Mobility Project [CH2017-7243]; Carl Tryggers Stiftelse [CTS 23:2433]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoeping University [2009 0097]

The transition to green and sustainable catalysts necessitates efficient and safe preparation techniques using abundant and renewable resources. Many metal nanoparticles (NPs) are excellent catalysts but suffer from poor colloidal stability. NP immobilization or fabrication of metal nanostructures on solid supports can avoid issues with NP aggregation and facilitate the reuse of catalysts, but it may result in a decrease in the catalytic performance of the NPs. Here, we show that well-defined colloidal silver, gold, and platinum NPs can be self-assembled in bacterial nanocellulose (BC) membranes, yielding BC-NP nanocomposites that are highly catalytically active using the reduction of 4-nitrophenol (4-NP) as a model reaction. The large effective surface area of BC enables the assembly of large quantities of NPs, resulting in materials with excellent catalytic performance. To address the mass transport limitations of reactants through the 3D nanofibrillar BC network, the membranes were dissociated using sonication to produce dispersed nanocellulose fibrils. This process dramatically reduced the time required for the adsorption of the NPs from days to minutes. Moreover, the catalytic performance of the nanofibril-supported NPs was drastically improved. A turnover frequency above 21,000 h(-1) was demonstrated, which is more than one order of magnitude higher than that for previously reported soft substrate-supported AuNP-based catalytic materials. The ease of fabrication, abundance, and low environmental footprint of the support material, along with reusability, stability, and unprecedented catalytic performance, make BC-NP nanocomposites a compelling option for green and sustainable catalysis., Funding Agencies|2009-00971 , the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Link??ping University [FFL15-0026, RMX18-0039]; Swedish Foundation for Strategic Research (SFF) [2021-04427]; Swedish Research Council (VR) [2009-00971]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University

As one of the major causes of antimicrobial resistance, beta-lactamase develops rapidly among bacteria. Detection of beta-lactamase in an efficient and low-cost point-of-care testing (POCT) way is urgently needed. However, due to the volatile environmental factors, the quantitative measurement of current POCT is often inaccurate. Herein, we demonstrate an artificial intelligence (AI)-assisted mobile health system that consists of a paper-based beta-lactamase fluorogenic probe analytical device and a smartphone-based AI cloud. An ultrafast broad-spectrum fluorogenic probe (B1) that could respond to beta-lactamase within 20 s was first synthesized, and the detection limit was determined to be 0.13 nmol/L. Meanwhile, a three-dimensional microfluidic paper-based analytical device was fabricated for integration of B1. Also, a smartphone-based AI cloud was developed to correct errors automatically and output results intelligently. This smart system could calibrate the temperature and pH in the beta-lactamase level detection in complex samples and mice infected with various bacteria, which shows the problem-solving ability in interdisciplinary research, and demonstrates potential clinical benefits., Funding Agencies|National Key R&D Program of China [2020YFA0709900]; National Natural Science Foundation of China [62288102, 22077101, 52073230]; Joint Research Funds of Department of Science & Technology of Shaanxi Province; Northwestern~Polytechnical University [2020GXLH-Z-008, 2020GXLH-Z-013]; Shaanxi Provincial Science Fund for Distinguished Young Scholars [2023-JC-JQ-32]; Key Research and Development Program of Shaanxi [2020ZDLGY13-04]; Fundamental Research Funds for the Central Universities and Innovation Foundation for Doctorate Dissertation of Northwestern Polytechnical University [CX2021121]

Mitophagy has a critical role in maintaining cellular homeostasis through acidic lysosomes engulfing excess or impaired mitochondria, thereby pH fluctuation is one of the most significant indicators for tracking mitophagy. Then such precise pH tracking demands the fluorogenic probe that has tailored contemporaneous features, including mitochondrial-specificity, excellent biocompatibility, wide pH-sensitive range of 8.0-4.0, and especially quantitative ability. However, available molecular probes cannot simultaneously meet all the requirements since it is extremely difficult to integrate multiple functionalities into a single molecule. To fully address this issue, we herein integrate two fluorogenic pH sensitive units, a mitochondria-specific block, cell-penetrating facilitator, and biocompatible segments into an elegant silica nano scaffold, which greatly ensures the applicability for real-time tracking of pH fluctuations in mitophagy. Most significantly, at a single wavelength excitation, the integrated pH-sensitive units have spectra-distinguishable fluorescence towards alkaline and acidic pH in a broad range that covers mitochondrial and lysosomal pH, thus enabling a ratiometric analysis of pH variations during the whole mitophagy. This work also provides constructive insights into the fabrication of advanced fluorescent nanoprobes for diverse biomedical applications., Funding Agencies|Linkoping University

Gadolinium chelates are employed worldwide today as clinical contrast agents for magnetic resonance imaging. Until now, the commonly used linear contrast agents based on the rare-earth element gadolinium have been considered safe and well-tolerated. Recently, concerns regarding this type of contrast agent have been reported, which is why there is an urgent need to develop the next generation of stable contrast agents with enhanced spin-lattice relaxation, as measured by improved T-1 relaxivity at lower doses. Here, we show that by the integration of gadolinium ions in cerium oxide nanoparticles, a stable crystalline 5 nm sized nanoparticulate system with a homogeneous gadolinium ion distribution is obtained. These cerium oxide nanoparticles with entrapped gadolinium deliver strong T-1 relaxivity per gadolinium ion (T-1 relaxivity, r(1) = 12.0 mM(-1) s(-1)) with the potential to act as scavengers of reactive oxygen species (ROS). The presence of Ce3+ sites and oxygen vacancies at the surface plays a critical role in providing the antioxidant properties. The characterization of radial distribution of Ce3+ and Ce4+ oxidation states indicated a higher concentration of Ce3+ at the nanoparticle surfaces. Additionally, we investigated the ROS-scavenging capabilities of pure gadolinium-containing cerium oxide nanoparticles by bioluminescent imaging in vivo, where inhibitory effects on ROS activity are shown., Funding Agencies|Swedish Research Council VR [2019-02409, 2020-05437]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]; Knut and Alice Wallenberg Foundation KAW [2014.0276, 18:399, 19:379]; Centre in Nanoscience and Nanotechnology at LiTH (CeNano) at Linkoping University; Swedish Foundation for Strategic Research (SSF) research infrastructure fellow program [RIF 140074]

We report the formation of silicide by annealing of a SiOx surface, with low coverage of Eu doped Gd2O3 nanoparticles. The annealing temperature required for removal of native oxide from the Si substrate decreases with close to 200 degrees C in presence of the nanoparticles. X-ray photoemission electron microscopy, low-energy electron microscopy and mirror electron microscopy are used to monitor the silicide formation and SiOx removal. Fragmentation of the nanoparticles is observed, and the SiOx layer is gradually removed. Eu migrates to clean Si areas during the annealing process, while Gd is found in areas where oxide is still present. This annealing process is clearly facilitated in the presence of rare-earth based nanoparticles, where nanoparticles are suggested to function as reaction sites to catalyze the oxygen removal and simultaneously form Eu based silicide. Reduction of the annealing temperature of SiOx substrates is also observed in presence of pure Eu3+ and Gd3+ ions. Simultaneous oxygen removal and EuSi formation enable this new rare-earth catalyzed annealing and silicide formation to find applications both within optoelectronics and processing microelectronic industry., Funding Agencies|Swedish Research Council (VR)Swedish Research Council [621-2013-5357]; Swedish government strategic faculty grant in material science (SFO, MATLIU) in Advanced Functional Materials (AFM) [2009-00971]; Centre in Nano science and technology (CeNano); Carl Tryggers Foundation [CTS 18:399, CTS19:379]; Swedish Foundation for Strategic Research (SSF) through the Strategic Mobility program [SM17-0026]