A near-infrared lysosomal probe for dynamic sulfur dioxide monitoring in inflammation.

Inflammation is a complex physiological response involving various cellular and molecular events. Sulfur dioxide (SO2), recognized as both an endogenous signaling molecule and anti-inflammatory agent, plays a crucial role in modulating inflammation and maintaining cellular homeostasis. To gain deeper insights into the dynamics of inflammation-related processes, real-time monitoring of SO2 concentrations within cellular organelles is imperative. Here, we developed a near-infrared fluorescent probe, R2, equipped with lysosomal targeting features. R2 effectively monitors dynamic SO2 concentration changes during inflammation. The fluorescence intensity at 703 nm of R2 shows a strong linear correlation with the concentration of SO2, displaying a rapid response time to SO2 within 10 s and maintaining excellent photostability. The successful application of R2 in elucidating dynamic SO2 concentration changes in lysosomal during cellular and rat inflammatory processes underscores its significant potential as a tool for understanding the pathogenesis of inflammation-related diseases.

A flexible nanofiber membrane containing dendritic oxygen probe for visual monitoring pressure distribution.

Pressure-sensitive paints (PSP) enable non-intrusive visualization of surface pressure distribution on model surface which is important for aerodynamic studies. However, conventional PSP materials suffer from photobleaching and inadequate sensitivity. In this work, we rationally designed and synthesized novel dendritic oxygen probes (PT1 and PT2) by covalently grafting fluorinated dendrons onto platinum tetrakis(pentafluorophenyl)porphyrin (PT0) (a common oxygen probe). Subsequently, PT2 loaded nanofibers membranes from polycaprolactone (PCL) were fabricated by electrospinning. Fabricated membranes showed high oxygen sensitivity (I0/I100 = 35.3) with excellent flexibility, good reversibility, and outstanding photostability (merely 2.0% intensity loss after prolonged irradiation). The pressure sensitivity was found around 0.73 % per kilopascal. Furthermore, significant variation in emission intensity with respect to the variation in air pressure (1.3-101.32 kPa), facilitates the naked eye visualization of the pressure distribution on the membrane surface. Such excellent oxygen and pressure sensitivity and photostability might be due to high fluorine contents of complex dendritic structure of PT2. This flexible fluorine-functionalized dendritic oxygen probe puts forward a facile and effective strategy to develop advanced PSP materials enabling accurate pressure mapping for aerodynamic studies.

Curative effect of capreomycin in adjuvant treatment of multidrug-resistant pulmonary tuberculosis and its effect on quality of life and immune function / 中国热带医学

@#Abstract: Objective To investigate the efficacy of capreomycin adjuvant therapy for multidrug-resistant pulmonary tuberculosis (MDR-TB) and its effect on quality of life and immune function. Methods Eighty-eight elderly pulmonary tuberculosis patients admitted to Affiliated Hospital of Hebei University from October 2019 to October 2020 were selected and divided into two groups according to the random number table method. The control group (n=44) used 4-6Am-Mfx（Lfx）-Pto-Cfz-Z-Hhigh-dose-E/5 Mfx（Lfx）-Cfz-Z-E, the research group (n=44) used capreomycin on the basis of the control group. The 6-Minute Walk Test (6MWT) measured value/predicted value and quality of life [36-Item Short Form Health Survey Questionnaire (SF-36)] scores, safety evaluation results, chest CT cavity and lesion absorption rate and sputum culture turned negative were compared between the two groups, and the serum procalcitonin (PCT) expression levels and immune function were detected before and after treatment. Results The 6MWT measured value/predicted value of the research group and control group before the treatment were (0.48±0.11) and (0.64±0.13), which were significantly higher than corresponding (0.51±0.12) and (0.58±0.14) after treatment (t=6.23, 2.520, P<0.05), the measured/expected value of 6MWT increased in both groups after treatment. Compared with the same group before treatment, the SF-36 scores for each dimension increased in both groups after treatment (P<0.01). The expression levels of serum PCT in the research group and control group before the treatment were (0.37±0.09) ng/mL and (0.12±0.03) ng/mL versus (0.36±0.11) ng/mL and (0.21±0.06) ng/mL after treatment (t=17.480, 7.940, P<0.01). Compared with the same group before treatment, serum PCT expression levels decreased in both groups after treatment. Compared with the same group before treatment, CD3+, CD4+ and CD4+/CD8+ were elevated in both groups after treatment (P<0.05 or P<0.01); after treatment, CD3+, CD4+, and CD4+/CD8+ were significantly higher in research group compared to the control group (t=4.21, 8.02, 2.04, P<0.05). The absorption rate of chest CT cavity and lesions and negative rate of sputum culture in the research group were 88.64% (39/44) and 81.82% (36/44), which were significantly higher than corresponding 63.64% (28/44) and 61.36% (27/44) in the control group (P<0.05). Conclusions　Capreomycin can improve the quality of life of MDR-TB patients, extend the 6-minute walking distance, and regulate serum PCT expression levels and immune function, to promote the absorption of chest CT cavity and lesions, and sputum culture to turn negative, and the security is acceptable.

Integrated Ideal-Bandgap Perovskite/Bulk-Heterojunction Solar Cells with Efficiencies > 24.

Here, the authors report a highly efficient integrated ideal-bandgap perovskite/bulk-heterojunction solar cell (IPBSC) with an inverted architecture, featuring a near infrared (NIR) polymer DTBTI-based bulk-heterojunction (BHJ) layer atop guanidinium bromide (GABr)-modified FA0.7 MA0.3 Pb0.7 Sn0.3 I3 perovskite film as the photoactive layer. The IPBSC shows cascade-like energy level alignment between the charge-extractionlayer/perovskite/BHJ and efficient passivation effect of BHJ on perovskite. Thanks to the well-matched energy level alignment and high-quality ideal bandgap-based perovskite film, an efficient charge transfer occurs between the charge-extraction-layer/perovskite/BHJ. Moreover, the NIR polymer DTBTI on the perovskite film leads to an improved NIR light response for the IPBSC. In addition, the O, S and N atoms in the DTBTI polymer yield a strong interaction with perovskite, which is conducive to reducing the defects of the perovskite and suppressing charge recombination. As a result, the solar cell achieves a power conversion efficiency (PCE) of 24.27% (certificated value at 23.4% with 0.283-volt voltage loss), currently the recorded efficiency for both IPBSCs and Pb-Sn alloyed PSCs, and which is over the highest efficiency of perovskite-organic tandem solar cell. Moreover, the thermal, humidity and long-term operational stabilities of the IPBSCs are also significantly improved compared with the control PSCs.

A near-infrared probe for the real-time detection of lysosomal pH in living cells under "wash free" conditions.

Lysosomal pH is an important indicator for the physiological state of eukaryotic cells. The real-time detection of intracellular lysosomal pH is critical for understanding and studying many physiological and pathological processes of cells. Herein, we designed and synthesized a series of novel pH sensors, namely W1, W2 and W3. By comparing the spectroscopic properties of the three molecules and their ability to target lysosomes in living cells, a specific probe W1 was selected for the quantitative analysis of lysosomal pH changes in live cells. W1 shows a fast, sensitive and highly selective red fluorescence response to an acidic pH value. The pKa value of W1 is 5.84, and the fluorescence intensity ratios of I743/I680 under acidic conditions show a good linear relationship with the pH value. In addition, W1 shows a 100-fold difference in fluorescence from an extracellular environment to an intracellular environment, allowing it to be used as a "wash free" staining probe to visualize the pH change of lysosomes. W1 was further applied to detect the changes of lysosomal pH during apoptosis and mitophagy. Thus, W1 is expected to be a potentially useful tool for monitoring the changes of lysosomal pH in cell-related physiological or pathological states.

New nanostructured extracellular potassium ion probe for assay of cellular K+ transport.

The concentration of potassium ion is an important indicator for human health, and its abnormality is often accompanied by various diseases. However, most tools currently used to study potassium ion transport are low throughput. Herein, we reported a new K+ fluorescent nanoprobe CP1-KS with high selectivity and sensitivity to K+ (fluorescence enhanced factor was up to 9.91 at 20 mM K+). The polymeric fluorescent probe CP1-KS was composed of the small-molecular K+ indicator KS and amphiphilic copolymer CP1. This sensor can be easily and uniformly dispersed in cell culture medium and is suitable for high throughput analysis. To assess the utility of the probe CP1-KS in biological field, this probe was employed as an extracellular fluorescent probe to monitor the efflux of K+ from cells (E coli, B. Subtilis 168, Hela and MCF-7 cells) under various stimulation including lysozyme, nigericin, digitonin, and ATP. Results demonstrated that CP1-KS is an effective analysis tool for extracellular K+ concentration. We believe that the nanoprobe has great potential in antibacterial drug screening, K+ ionophore function, K+ channel activity, cell membrane permeability analysis or other K+ related field in the future.

Magnetically Reusable and Well-dispersed Nanoparticles for Oxygen Detection in Water.

In this study, we aimed to synthesize magnetically well-dispersed nanosensors for detecting dissolved oxygen (DO) in water, and explore their biological applications. Firstly, we synthesized two kinds of magnetic nanoparticle with average sizes of approximately 82 nm by one-step emulsion polymerization: polystyrene magnetic nanoparticles (Fe3O4@Os1-PS) and polymethylmethacrylate magnetic nanoparticles (Fe3O4@Os1-PMMA). Both types of nanoparticle present good dispersibility and fluorescence stability. The nanoparticles could be used as oxygen sensors that exhibited a high DO-sensitivity response in the range 0-39.30 mg/L, with a strong linear relationship. The nanoparticles have good magnetic properties, and so they could be recycled by magnet for further use. Recovered Fe3O4@Os1-PS still presented high stability after continued use in oxygen sensing for one month. Furthermore, Fe3O4@Os1-PS was employed for detecting the bacterial oxygen consumption of Escherichia coli (E-coli) to monitor the metabolism of bacteria. The results show that Fe3O4@Os1-PS provide high biocompatibility and non-toxicity. Polystyrene magnetic nanoparticles therefore present significant potential for application in biological oxygen sensing.

A Dual pH/O2 Sensing Film Based on Functionalized Electrospun Nanofibers for Real-Time Monitoring of Cellular Metabolism.

Real-time monitoring of dissolved oxygen (DO) and pH is of great significance for understanding cellular metabolism. Herein, a dual optical pH/O2 sensing membrane was prepared by the electrospinning method. Cellulose acetate (CA) and poly(ε-caprolactone) (PCL) nanofiber membrane blended with platinum (II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin (PtTFPP) was used as the DO sensing matrix, upon which electrospun nanofiber membrane of chitosan (CS) coupled with fluorescein 5-isothiocyanate (FITC) was used as the pH sensing matrix. The electrospun sensing film prepared from biocompatible biomaterials presented good response to a wide range of DO concentrations and physiological pH. We used it to monitor the exracellular acidification and oxygen consumption levels of cells and bacteria. This sensing film can provide a luminescence signal change as the DO and pH change in the growth microenvironment. Due to its advantages of good biocompatibility and high stability, we believe that the dual functional film has a high value in the field of biotechnology research.

GdDO3NI Enhanced Magnetic Resonance Imaging Allows Imaging of Hypoxia After Brain Injury.

BACKGROUND: Brain tissue hypoxia is a common consequence of traumatic brain injury (TBI) due to the rupture of blood vessels during impact and it correlates with poor outcome. The current magnetic resonance imaging (MRI) techniques are unable to provide a direct map of tissue hypoxia. PURPOSE: To investigate whether GdDO3NI, a nitroimidazole-based T1 MRI contrast agent allows imaging hypoxia in the injured brain after experimental TBI. STUDY TYPE: Prospective. ANIMAL MODEL: TBI-induced mice (controlled cortical impact model) were intravenously injected with either conventional T1 agent (gadoteridol) or GdDO3NI at 0.3 mmol/kg dose (n = 5 for each cohort) along with pimonidazole (60 mg/kg) at 1 hour postinjury and imaged for 3 hours following which they were euthanized. FIELD STRENGTH/SEQUENCE: 7 T/T2 -weighted spin echo and T1 -weighted gradient echo. ASSESSMENT: Injured animals were imaged with T2 -weighted spin-echo sequence to estimate the extent of the injury. The mice were then imaged precontrast and postcontrast using a T1 -weighted gradient-echo sequence for 3 hours postcontrast. Regions of interests were drawn on the brain injury region, the contralateral brain as well as on the cheek muscle region for comparison of contrast kinetics. Brains were harvested immediately post-imaging for immunohistochemical analysis. STATISTICAL TESTS: One-way analysis of variance and two-sample t-tests were performed with a P < 0.05 was considered statistically significant. RESULTS: GdDO3NI retention in the injury region at 2.5-3 hours post-injection was significantly higher compared to gadoteridol (mean retention fraction 63.95% ± 27.43% vs. 20.68% ± 7.43% for gadoteridol at 3 hours) while it rapidly cleared out of the muscle region. Pimonidazole staining confirmed the presence of hypoxia in both gadoteridol and GdDO3NI cohorts, and the later cohort showed good agreement with MRI contrast enhancement. DATA CONCLUSION: GdDO3NI was successfully shown to visualize hypoxia in the brain post-TBI using T1 -weighted MRI at 2.5-3 hours postcontrast. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Effectiveness of a case management model in newly treated smear-positive pulmonary tuberculosis patients.

INTRODUCTION: To investigate the effectiveness of the case management mode on the application of smear-positive pulmonary tuberculosis patients. METHODOLOGY: This was a randomized control trial. A total of 70 newly diagnosed smear-positive pulmonary tuberculosis patients were recruited and been randomly divided into experimental group and control group, with 35 participants in each group. In the experimental group, patients received the tuberculosis case management mode based on the conventional management mode. In the control group, patients received the routine management mode. We compared the knowledge, attitude, and practice score; sputum-negative conversion rate, effective imaging rate of the two groups at the time of initial admission, discharge, and one month after discharge. RESULTS: The results showed that there was no significant difference in baseline data between the two groups (p > 0.05); at the time of discharge and one month after discharge, the knowledge, belief, behavior, sputum-negative conversion rate, and imaging examination effective rate of the experimental group were higher than those of the control group (p < 0.05). CONCLUSIONS: The case management mode can improve the knowledge, attitude, and practice level; sputum-negative conversion rate; and imaging efficiency of newly treated smear-positive pulmonary tuberculosis patients.

Automatic light-adjusting electrochromic device powered by perovskite solar cell.

Electrochromic devices can modulate their light absorption under a small driving voltage, but the requirement for external electrical supplies causes response-lag. To address this problem, self-powered electrochromic devices have been studied recently. However, insensitivity to the surrounding light and unsatisfactory stability of electrochromic devices have hindered their critical applications. Herein, novel perovskite solar cell-powered all-in-one gel electrochromic devices have been assembled and studied in order to achieve automatic light adjustment. Two alkynyl-containing viologen derivatives are synthesized as electrochromic materials, the devices with very high stability (up to 70000 cycles) serves as the energy storage and smart window, while the perovskite solar cell with power-conversion-efficiency up to 18.3% serves as the light detector and power harvester. The combined devices can automatically switch between bleached and colored state to adjust light absorption with variable surrounding light intensity in real-time swiftly, which establish significant potentials for applications as modern all-day intelligent windows.

Rational Design of a Polymer-Based Ratiometric K+ Indicator for High-Throughput Monitoring Intracellular K+ Fluctuations.

Highly selective fluorescent K+ sensors are of great importance for monitoring K+ fluctuations in various biological processes. In particular, highly efficient ratiometric K+ sensors that can emit in dual wavelengths and facilitate the quantitative determination of K+ are highly anticipated. Herein, we present the first polymer-based ratiometric fluorescent K+ indicator (PK1) for quantitatively detecting K+ in aqueous solutions and high-throughput monitoring K+ fluctuations in living cells. PK1 was synthesized by conjugating a small molecular K+ probe and a red emission reference dye to a hydrophilic polymer skeleton. The newly synthesized PK1 can form highly stable nanoparticles in aqueous solutions and work in 100% water without the aid of any organic solvents or surfactants. PK1 is sensitive to K+ with a fluorescence enhancement of sevenfold after interactions with K+ at 1000 mM and inert to other metal ions, physiological pH, or dye concentration vibrations. More importantly, the fluorescence intensity ratio at 572 and 638 nm is linearly correlated with log [K+] in the range of 2-500 mM (R2 = 0.998), which will facilitate the quantitative detection of K+. Practical application of PK1 in detecting different K+-rich samples demonstrates its great potential in quantitative detection of K+. PK1 can be quickly internalized by live cells and shows no obvious cytotoxicity. We also demonstrate that PK1 could be used for monitoring K+ fluctuations under different stimulations by using a confocal microscope and especially a microplate reader, which is high throughput and time saving. The rational design of PK1 will broaden the design concept of ratiometric fluorescent K+ sensors and facilitate the quantitative detection of K+.

Close Temporal Relationship between Oscillating Cytosolic K+ and Growth in Root Hairs of Arabidopsis.

Root hair elongation relies on polarized cell expansion at the growing tip. As a major osmotically active ion, potassium is expected to be continuously assimilated to maintain cell turgor during hair tip growth. However, due to the lack of practicable detection methods, the dynamics and physiological role of K+ in hair growth are still unclear. In this report, we apply the small-molecule fluorescent K+ sensor NK3 in Arabidopsis root hairs for the first time. By employing NK3, oscillating cytoplasmic K+ dynamics can be resolved at the tip of growing root hairs, similar to the growth oscillation pattern. Cross-correlation analysis indicates that K+ oscillation leads the growth oscillations by approximately 1.5 s. Artificially increasing cytoplasmic K+ level showed no significant influence on hair growth rate, but led to the formation of swelling structures at the tip, an increase of cytosolic Ca2+ level and microfilament depolymerization, implying the involvement of antagonistic regulatory factors (e.g., Ca2+ signaling) in the causality between cytoplasmic K+ and hair growth. These results suggest that, in each round of oscillating root hair elongation, the oscillatory cell expansion accelerates on the heels of cytosolic K+ increment, and decelerates with the activation of antagonistic regulators, thus forming a negative feedback loop which ensures the normal growth of root hairs.

Characterization and elimination of artificial non-covalent light Chain dimers in reduced CE-SDS analysis of pertuzumab.

Capillary electrophoresis sodium dodecyl sulfate (CE-SDS), either in reduced (rCE-SDS) or non-reduced (nrCE-SDS) form, is widely used for purity evaluation and impurity analysis of monoclonal antibody (mAb) drugs. The accuracy of the method may be interfered by artificial species resulted from sample preparation or electrophoresis operation if it is not well optimized. In a routine analysis of pertuzumab for both innovator Perjeta® and biosimilar HLX11 samples, a cluster of unknown peaks located between light chain (LC) and heavy chain (HC) were observed in rCE-SDS and making the purity of (LC + HC)% unacceptable. They can hardly be reduced by regular method optimization such as changing buffer pH, denaturing temperature or incubation time to achieve the (LC + HC)% expectation. Here, the peaks are first characterized and determined to be non-covalently formed LC-LC dimers by multiple techniques including reversed-phase liquid chromatography-mass spectrometry (LC-MS). These artifacts are then eliminated through enhancing capillary separation temperature to 60 °C and decreasing the separation voltage to 9.5 kV, an unusual CE-SDS operation setting. Finally, a developed rCE-SDS method is presented for successful evaluation of pertuzumab purity and impurities, which is further confirmed by an alternative reduced microchip-based gel electrophoresis. In summary, the developed method provided an accurate and reliable purity evaluation and size variant profiling for batch releasing, stability testing and quality study of reduced pertuzumab samples.

Polymer matrix: A good substrate material for oxygen probes used in pressure sensitive paints.

Over the past few years, surface pressure measurement has fundamental importance in many areas, particularly, aerodynamic research. Conventional methods involve pressure taps, but due to the nature of these pressure taps, only pressure information of isolated points on model surface is available, which limit their applications in aerodynamics studies. Recently the newly developed approach, pressure sensitive paint (PSP) has revolutionized such pressure measurements and various PSP materials have been developed for aerodynamics research. Hence, the main focus of this review is to study the interactions of polymers with different oxygen probes and polymeric role as supporting material in the maturation of PSP. In this review, the selected PSP materials are categorically elucidated in terms of their advantages and limitations to give a fair insight about their applicability. Further, we have summarized and articulated such particular optical oxygen sensing materials either that have been used as PSP or have potential to be used as PSP materials.

Development of a molecular K+ probe for colorimetric/fluorescent/photoacoustic detection of K.

The potassium ion (K+) plays significant roles in many biological processes. To date, great efforts have been devoted to the development of K+ sensors for colorimetric, fluorescent, and photoacoustic detection of K+ separately. However, the development of molecular K+ probes for colorimetric detection of urinary K+, monitoring K+ fluxes in living cells by fluorescence imaging, and photoacoustic imaging of K+ dynamics in deep tissues still remains an open challenge. Herein, we report the first molecular K+ probe (NK2) for colorimetric, fluorescent, and photoacoustic detection of K+. NK2 is composed of 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) as the chromophore and phenylazacrown-6-lariat ether (ACLE) as the K+ recognition unit. Predominate features of NK2 include a short synthetic procedure, high K+ selectivity, large detection range (5-200 mM), and triple-channel detection manner. NK2 shows good response to K+ with obvious color changes, fluorescence enhancements (about threefold), and photoacoustic intensity changes. The existence of other metal ions (including Na+, Mg2+, Ca2+, Fe2+) and pH changes (6.5-9.0) have no obvious influence on K+ sensing of NK2. Portable test strips stained by NK2 can be used to qualitatively detect urinary K+ by color changes for self-diagnosis of diseases induced by high levels of K+. NK2 can be utilized to monitor K+ fluxes in living cells by fluorescent imaging. We also find its excellent performance in photoacoustic imaging of different K+ concentrations in the mouse ear. NK2 is the first molecular K+ probe for colorimetric, fluorescent, and photoacoustic detection of K+ in urine, in living cells, and in the mouse ear. The development of NK2 will broaden K+ probes' design and extend their applications to different fields. Graphical abstract.

High-Performance All-Polymer Solar Cells Enabled by n-Type Polymers with an Ultranarrow Bandgap Down to 1.28 eV.

Compared to organic solar cells based on narrow-bandgap nonfullerene small-molecule acceptors, the performance of all-polymer solar cells (all-PSCs) lags much behind due to the lack of high-performance n-type polymers, which should have low-aligned frontier molecular orbital levels and narrow bandgap with broad and intense absorption extended to the near-infrared region. Herein, two novel polymer acceptors, DCNBT-TPC and DCNBT-TPIC, are synthesized with ultranarrow bandgaps (ultra-NBG) of 1.38 and 1.28 eV, respectively. When applied in transistors, both polymers show efficient charge transport with a highest electron mobility of 1.72 cm2 V-1 s-1 obtained for DCNBT-TPC. Blended with a polymer donor, PBDTTT-E-T, the resultant all-PSCs based on DCNBT-TPC and DCNBT-TPIC achieve remarkable power conversion efficiencies (PCEs) of 9.26% and 10.22% with short-circuit currents up to 19.44 and 22.52 mA cm-2 , respectively. This is the first example that a PCE of over 10% can be achieved using ultra-NBG polymer acceptors with a photoresponse reaching 950 nm in all-PSCs. These results demonstrate that ultra-NBG polymer acceptors, in line with nonfullerene small-molecule acceptors, are also available as a highly promising class of electron acceptors for maximizing device performance in all-PSCs.

A mitochondria-targeting NIR fluorescent potassium ion sensor: real-time investigation of the mitochondrial K+ regulation of apoptosis in situ.

The first NIR fluorescent mitochondria-targeting K+ sensor, denoted as TAC-Rh, was developed. The produced sensor consists of a rhodamine analog as the fluorophore and triazacryptand (TAC) as the K+ recognition unit. Compared to the K+ sensors reported previously, TAC-Rh exhibits two unique optical properties: the largest Stokes shifts (120 nm) and the longest emission peak wavelength (720 nm). With the assistance of this novel sensor, real-time changes of K+ concentrations in mitochondria during apoptosis were monitored for the first time. Moreover, it was also the first time that the relationship between mitochondrial K+ flux and apoptosis was investigated in real time using fluorescence imaging.

Tricolor dual sensor for ratiometrically analyzing potassium ions and dissolved oxygen.

A potassium ion­oxygen (K+-O2) dual fluorescent sensing film was developed. The film contains three probes, which are K+ probe (KS), O2 probe (OS), and reference probe (RP) in a polymer film composed of poly(ethylene glycol) methyl ether methacrylate (PEGMA), poly(ethylene glycol) dimethacrylate (PEGDMA) and methacrylic acid (MAA). The RP showed blue emission, the KS exhibited green emission, and the OS showed red emission. The emission peaks of three probes do not interfere with each other, which enable the sensing film to be used for ratiometrically and quantitatively detecting the concentrations of K+ and dissolved oxygen (DO). The sensing films showed high sensitivity and selectivity to potassium ions over other metal ions and also good sensitivity for DO from deoxygenated to oxygenated conditions. The sensing film was demonstrated to be capable of analyzing K+ and DO concentrations with experimental errors smaller than ±8.5% in aqueous solutions, showing the potential applications of the sensing films.

Electron/energy co-transfer behavior and reducibility of Cu-chlorophyllin-bonded carbon-dots.

Cu-chlorophyllin-bonded carbon dots (CCPh-CDs) have been synthesized at room temperature, and the energy/electron co-transfer behavior between Cu-chlorophyllin molecules (CCPh) and carbon dots (CDs) is investigated via various techniques. The mean diameters of CDs and CCPh-CDs are 2.8 nm and 3.1 nm, respectively, measured by HRTEM. The absorption spectra of CCPh-CDs show two parts: the absorptions of CDs and CCPh are in the wavelength range of 300-500 nm. The PL spectra of CCPh-CDs exhibit very weak intensities, and with the decreasing of CCPh content on CDs, the corresponding intensity increases. Luminescent decay spectra show that the PL decay times of CCPh and CCPh-CDs with the highest CCPh content are single-exponentially fitted to be 3.20 ns and 12.64 ns, respectively. Furthermore, based on the electron transfer and reducibility of CCPh-CDs, Ag/Ag2O nanoparticles with a mean diameter of 10 nm can be easily prepared at room temperature under ultraviolet irradiation. The PL measurement result reveals that both electron transfer and FRET behavior take place from CCPh-CDs to Ag.