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Fluorene nucleus derivatives show great potential for building outstanding fluorescence probes. In this paper, a novel fluorescent probe was developed by reacting with fluorene core with azacyclobutane, which exhibits typical solvation chromogenic effect in solvent. The fluorescence of the probe quenched in highly polar solvent. Based on this phenomenon, a novel fluorescence system for trace water was constructed. The response of this probe was fast (30 s) and sensitive for the detection of trace water in organic solvents, and the detection limit of water content in DMSO reached 0.13%. In addition, the probe can also be made as a test strip combined with homemade portable device and a smartphone for rapid detection of trace water. The luminescence mechanism of the probe is theoretically calculated based on time‐contained density functional theory (TDDFT). To showcase its practicality, it has been applied for the detection of trace water in honey and alcohol by dipstick. This method provides a new idea for designing efficient fluorescent probes based on dipstick and mobile phone rapid detection. [ABSTRACT FROM AUTHOR]

The carbon capture and storage (CCS) technique gains much attention due to its role in reducing CO2 emissions. By introducing flexible CCS devices into conventional power plants, the low‐carbon economic operation of the power system can be achieved. However, the uncertainty of renewable energy makes it hard to obtain an optimal operation policy. First, the detailed model of CCS consisting of bypass venting stacks, solvent storage tanks, absorber, and stripper is described. Then, a low‐carbon economic dispatch model of the power system with CCS is proposed to minimize the total operation and renewable energy abandonment penalty costs. Next, the problem is reformulated as multi‐stage stochastic programming, and the stochastic dual dynamic programming (SDDP) method is applied to relieve the computation burden. To control the probability of stopping the algorithm prematurely, a new stopping criterion based on a two‐sided hypothesis test is proposed. Finally, the effectiveness of the proposed model and the new stopping criterion is demonstrated by case studies on a practical power system. [ABSTRACT FROM AUTHOR]

Photobiological chemical production is of great importance for solar energy storage and clean fuel generation. One rising strategy for solar fuel production is to enhance the original catalytic efficiency of non-photosynthetic cells by photosensitization of light-harvesting semiconducting nanomaterials. However, endowing cells with a new photocatalytic property to meet the ever-growing demands for environmentally-friendly processes to synthesize multifarious desirable chemicals is still a huge challenge. Herein, we report that a fungus, Saccharomyces cerevisiae, with neither photosynthetic properties nor hydrogen production abilities is endowed with efficient and sustainable light-driven hydrogen production (1063.51 μmol g−1CdS h−1) via the synergistic action of in situ biosynthesized intracellular CdS nanodots (nCdS) and ethanol dehydrogenases (ADH) from yeast. The catalytic mechanism indicates that the photoelectrons from nCdS were transferred to the activated water molecules located in the ADH combined with nCdS, realizing high-efficiency photocatalytic hydrogen production. This finding provides prospective guidance for endowing cells with sustainable and efficient conversion of solar energy by inducing in situ biosynthesized bionic minerals. [ABSTRACT FROM AUTHOR]

In this study, we designed a fluorimetric assay for ultrasensitive determination of microRNA-141 based on WS2 quantum dots (WS2 QDs) and concatenated DNA circuit-assembled DNAzymes. WS2 QDs are synthesized using sodium tungstate and cysteine as W and S sources, and the use of biomass materials as a precursor is environment-friendly. The presence of microRNA-141 can trigger the CHA and HCR, leading to the formation of long dsDNA nanochains with numerous HRP-mimicking DNAzymes. The o-phenylenediamine structure was oxidized to 2,3-diaminophenazine by the DNAzymes. WS2 QDs could be quenched by 2,3-diaminophenazine via the inner filter effect. This method is highly sensitive for the analysis of microRNA-141 with a limit of detection of 2.7 fM. The designed strategy has no measurable response to four other microRNAs. The WS2 QDs-based sensor was used for the microRNA-141 assay in human serum and microRNA-141 expression in MDA-MB-231 cells. This newly developed biosensor shows great potential for the analysis of biomarkers and early diagnosis of microRNA-related diseases. [ABSTRACT FROM AUTHOR]

Thrombin facilitates the aggregation of platelet in hemostatic processes and participates in the regulation of cell signaling. Therefore, the development of thrombin sensors is conducive to comprehending the role of thrombin in the course of a disease. Biosensors based on aptamers screened by SELEX have exhibited superiority for thrombin detection. In this review, we summarized the aptamer-based sensors for thrombin detection which rely on the specific recognitions between thrombin and aptamer. Meanwhile, the unique advantages of different sensors including optical and electrochemical sensors were also highlighted. Especially, these sensors based on electrochemistry have the potential to be miniaturized, and thus have gained comprehensive attention. Furthermore, concerns about aptamer-based sensors for thrombin detection, prospects of the future and promising avenues in this field were also presented. [ABSTRACT FROM AUTHOR]

Chemotherapy for cancer treatment is widely used but remains restricted by several limitations, including inefficient drug delivery and concomitant adverse side effects. Herein, we report a new prodrug-based self-assembled nanoparticle for the efficient treatment of cancer. Amphiphilic prodrug molecules (3′,5′-dioleoyl floxuridine, DOF) were constructed to form prodrug nanoparticles (DOF NPs) through a self-assembly process in water via hydrophobic interactions. The DOF NPs with high stability can be quickly enriched in tumor cells and release the floxuridine drug via hydrolysis of ester bonds by esterase. In vitro experiments reveal that the DOF NPs possess satisfactory tumor killing effects and weak toxicity and side effects. These unique features could further promote the research progress of prodrug-based self-assembled strategies for the application of chemotherapy in cancer. [ABSTRACT FROM AUTHOR]

A wind energy conversion system is mainly operated in a partial-load region and a full-load region. In the partial-load region, the primary objective is to maximize energy conversion efficiency, whereas the main goal is maintaining the output power at the rated level in the full-load region. The two control regions are switched in accordance with prevailing wind speed. However, steep and large changes of generator power, as well as mechanical loads, may be experienced during switching transient, which bring about negative impacts on power system reliability and turbine lifetime. This paper presented an advanced model-predictive control considering switching performance improvement. The proposed method not only achieved the control objectives in both two control regions, but also mitigated uncertain power fluctuations and mechanical loads during control mode switching. This high switching performance benefited from the presented dynamic switching transient process driven by the defined wind speed crossing events. During switching transient, system operating states were transferred along with the proposed dynamic vector. Small-signal analysis was employed to prove the good stability and dynamic performance of the system in switching transients. Simulation and hardware-in-the-loop experimental studies verified the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

When the wind power electricity system working above the rated wind speed, the disturbed wind speed can lead to the output ripple easily, which causes a significant negative influence on the stability of the power grid. In order to overcome this disadvantage, this paper discusses the mixed $$H_2/H_{\infty }$$ pitch angle control design problem for the nonlinear wind turbine generator system, where the turbulence is regarded as the disturbance input. Especially, the global exact linearization and the pole placement techniques are also applied to guarantee the desired control performance and expected dynamic characteristics in the situation of a large-scale variety of the system operation points. The simulation results show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

DNAzymes hold promise for gene-silencing therapy, but the lack of sufficient cofactors in the cell cytoplasm, poor membrane permeability, and poor biostability have limited the use of DNAzymes in therapeutics. We report a DNAzyme-MnO2 nanosystem for gene-silencing therapy. MnO2 nanosheets adsorb chlorin e6-labelled DNAzymes (Ce6), protect them from enzymatic digestion, and efficiently deliver them into cells. The nanosystem can also inhibit 1O2 generation by Ce6 in the circulatory system. In the presence of intracellular glutathione (GSH), MnO2 is reduced to Mn2+ ions, which serve as cofactors of 10-23 DNAzyme for gene silencing. The release of Ce6 generates 1O2 for more efficient photodynamic therapy. The Mn2+ ions also enhance magnetic resonance contrast, providing GSH-activated magnetic resonance imaging (MRI) of tumor cells. The integration of fluorescence recovery and MRI activation provides fluorescence/MRI bimodality for monitoring the delivery of DNAzymes. [ABSTRACT FROM AUTHOR]

pHLIP statt Flop: Die Funktionalisierung mesoporöser Kieselgelnanopartikel (MSNs) mit pHLIPss ‐ Peptid ergab ein Transportsystem mit gezielter Wirkstoff ‐ Freisetzung in der sauren Mikroumgebung von Tumoren. Bei niedrigen pH ‐ Werten schiebt sich pHLIPss in die Zellmembran ein und sorgt für die Aufnahme der Träger durch die Zelle; dort wird dann der Partikelinhalt durch Spaltung von pHLIPss ‐ Disulfidbrücken freigesetzt (siehe Schema). [ABSTRACT FROM AUTHOR]

The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs' chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions. [ABSTRACT FROM AUTHOR]

In this work, a novel bright yellow fluorescent carbon dots (CDs) was synthesized from N-methyl-1,2-phenylenediamine hydrochloride in ethanol solvent through the solvothermal method. The obtained carbon dots had no fluorescence in water, but could specifically light up in the cell which makes the staining process without washing. Interestingly, the imaging process can be performed by simply shaking the culture with the cells for only 1 min, indicating ultrafast and easy to operate fluorescence imaging. Moreover, the carbon dots with abundant amino functional groups had good lysosome targeting properties (the Pearson's correlation coefficient is 0.92) and could achieve the ultrafast lysosome imaging in cell and zebrafish and monitoring cell apoptosis status. This is the first lysosome targeting carbon dots that allows the combination of a short incubation at the second-level with wash-free process providing great potential for continuous observation lysosome in vivo. The obtained carbon dots can not only accumulate in lysosome rapidly by the clathrin-mediated endocytosis and were used for wash-free in lysosome and zebrafish imaging, but also monitor the dynamic change of lysosomal apoptosis. Image 1 • The method has intrinsic lysosome targeting without further modification. • The carbon dots can accumulate in lysosomes within 1 min by the clathrin-mediated endocytosis. • The obtained carbon dots were used for wash-free lysosome imaging in living and fixed cells. • The carbon dots can monitor the dynamic change of lysosomal apoptosis. • The obtained carbon dots were also used for ultrafast and wash-free imaging in zebrafish. [ABSTRACT FROM AUTHOR]

In this paper, a s plit-aptamer m ediated r egenerable t emperature-sensitive (SMRT) electrochemical biosensor was constructed for the detection of exosomes. The split-aptamer used in this SMRT biosensor was composed of two fragments, one of which was immobilized on the surface of an electrode via sulfhydryl groups and named split-a and the other was labelled with methylene blue and named split-b. The two fragments could form sandwich structures at the electrode surface via target-induced self-assembly in the presence of target exosomes at 4 °C in PBS, and then realizing the detection of exosomes via voltammetry. In addition, due to the temperature sensitivity of the split-aptamer, the electrode could be regenerated through temperature-induced disassembly of the sandwich structures. Consequently, the SMRT biosensor realized sensitive and specific analysis of target exosomes with a limit of detection of 1.5 × 106 particles/mL and could be quickly and easily regenerated by washing with PBS at 37 °C for 30 s without any additives. This is the first study on the construction of a reproducible electrochemical biosensor using a split-aptamer for the specific detection of tumour exosomes, and may provide an innovative strategy for the economical and efficient design of regenerable electrochemical biosensors. [Display omitted] • A split-aptamer mediated regenerable temperature-sensitive (SMRT) biosensor was built for the first time. • The sensitive and specific detection of SMMC-7721 exosomes was successful implementation. • The SMRT biosensor could be regenerated simply and quickly by adjusting the temperature to 37 °C in 30 s. [ABSTRACT FROM AUTHOR]

Fluorene nucleus derivatives show great potential for building outstanding fluorescence probes. In this paper, a novel fluorescent probe was developed by reacting with fluorene core with azacyclobutane, which exhibits typical solvation chromogenic effect in solvent. The fluorescence of the probe quenched in highly polar solvent. Based on this phenomenon, a novel fluorescence system for trace water was constructed. The response of this probe was fast (30 s) and sensitive for the detection of trace water in organic solvents, and the detection limit of water content in DMSO reached 0.13%. In addition, the probe can also be made as a test strip combined with homemade portable device and a smartphone for rapid detection of trace water. The luminescence mechanism of the probe is theoretically calculated based on time-contained density functional theory (TDDFT). To showcase its practicality, it has been applied for the detection of trace water in honey and alcohol by dipstick. This method provides a new idea for designing efficient fluorescent probes based on dipstick and mobile phone rapid detection., (© 2024 John Wiley & Sons Ltd.)

Photoacoustic (PA) imaging technology, a three-dimensional hybrid imaging modality that integrates the advantage of optical and acoustic imaging, has great application prospects in molecular imaging due to its high imaging depth and resolution. To endow PA imaging with the ability for real-time molecular visualization and precise biomedical diagnosis, numerous activatable molecular PA probes which can specifically alter their PA intensities upon reacting with the targets or biological events of interest have been developed. This review highlights the recent developments of activatable PA probes for precise biomedical applications including molecular detection of the biotargets and imaging of the biological events. First, the generation mechanism of PA signals will be given, followed by a brief introduction to contrast agents used for PA probe design. Then we will particularly summarize the general design principles for the alteration of PA signals and activatable strategies for developing precise PA probes. Furthermore, we will give a detailed discussion of activatable PA probes in molecular detection and biomedical imaging applications in living systems. At last, the current challenges and outlooks of future PA probes will be discussed. We hope that this review will stimulate new ideas to explore the potentials of activatable PA probes for precise biomedical applications in the future.

The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs' chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions.

The detection of enzyme activity can provide valuable insights into clinical diagnosis. Herein, we synthesize gold nanobipyramids@MnO2 nanoparticles (AMNS) as the surface-enhanced Raman spectroscopy (SERS) substrate for the first time and design a "turn-on" SERS strategy for the detection of enzyme activity without the need for a complicated SERS nanotag preparation process. In the presence of alkaline phosphatase (ALP), 2-phosphate-l-ascorbic acid trisodium salt (AAP) can be hydrolyzed to ascorbic acid (AA), which can etch the shell of AMNS by reducing MnO2 to Mn2+. The cracked MnO2 shell-caused electromagnetic field enhancement from AMNS can give rise to a significant increase in the Raman intensity of the adsorbed molecules (i.e., crystal violet, CV) on the surfaces of nanobipyramids. Thus, the ALP activity can be accurately quantified based on the MnO2 shell thickness dependent Raman signal output from CV. A linear dynamic range from 0.4 to 20 mU mL-1 with a detection limit of 0.04 mU mL-1 is achieved, which is more sensitive than other spectroscopic methods for ALP detection. Because of its advantages of sensitivity, convenience and versatility, this approach provides a new perspective to disease-related biomolecular detection in the future.

As one kind of redox active layered transition-metal dioxide nanomaterials, single-layer manganese dioxide (MnO 2 ) nanosheets have gained significant research attention in the fields of biosensing and biomedicine because of their large surface area, intense and broad optical absorption, strong oxidation ability, catalytic activity, and robust mechanical properties. This review provides a brief overview of the recent advances in the development of MnO 2 nanosheet-based biosensors, bioimaging as well as drug delivery for cancer therapy. The methodologies for the preparation of MnO 2 nanosheets are summarized, followed by an introduction of the nanostructure and properties of MnO 2 nanosheets. Special attention is paid to their applications in biosensing, bioimaging and cancer therapy. Future perspectives and the challenges of high-performance MnO 2 nanosheets are also discussed.

Because of excellent photoluminescence properties, robust chemical inertness, and low cytotoxicity of silicon nanoparticles (Si NPs), exploration of their applications in bioimaging is of great interest. Up to date, a method to synthesis Si NPs with high fluorescence quantum yield (QY) is still challenging. This situation limits the further applications of Si NPs. In this work, we report a mild, simple, and green one-pot method to synthesis N-doped fluorescent Si NPs with an ultrahigh QY up to 62%, using ethylenediaminetetraacetic acid disodium salt as an effective reductant. The obtained ultrabright Si NPs have properties such as relative small size (about 2 nm), water dispersibility, robust stability, and biocompatibility. The as-prepared Si NPs were further applied for cellular imaging with satisfactory results, indicating their great potential in bioimaging applications.

Carbon dots (CDs) have a wide range of applications in chemical, physical and biomedical research fields. We are particularly interested in the use of CDs as fluorescence nanomaterials for targeted tumor cell imaging. One of the important aspects of success is to enhance the fluorescence quantum yields (QY) of CDs as well as increase their targetability to tumor cells. However, most of the reported CDs are limited by relative low QY. In the current study, for the first time, one-step synthesis of highly luminescent CDs by using folic acid (FA) as single precursor was obtained in natural water through hydrothermal method. The as-prepared CDs exhibited QY as high as 94.5% in water, which is even higher than most of organic fluorescent dyes. The obtained CDs showed excellent photoluminescent activity, high photostability and favorable biocompatibility. The FA residuals in CDs led to extraordinary targetability to cancer cells and promoted folate receptor-mediated cellular uptake successfully, which holds a great potential in biological and bioimaging studies.

DNAzymes hold promise for gene-silencing therapy, but the lack of sufficient cofactors in the cell cytoplasm, poor membrane permeability, and poor biostability have limited the use of DNAzymes in therapeutics. We report a DNAzyme-MnO2 nanosystem for gene-silencing therapy. MnO2 nanosheets adsorb chlorin e6-labelled DNAzymes (Ce6), protect them from enzymatic digestion, and efficiently deliver them into cells. The nanosystem can also inhibit (1)O2 generation by Ce6 in the circulatory system. In the presence of intracellular glutathione (GSH), MnO2 is reduced to Mn(2+) ions, which serve as cofactors of 10-23 DNAzyme for gene silencing. The release of Ce6 generates (1)O2 for more efficient photodynamic therapy. The Mn(2+) ions also enhance magnetic resonance contrast, providing GSH-activated magnetic resonance imaging (MRI) of tumor cells. The integration of fluorescence recovery and MRI activation provides fluorescence/MRI bimodality for monitoring the delivery of DNAzymes., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)