Bifurcation, chaotic behaviors and solitary wave solutions for the fractional Twin-Core couplers with Kerr law non-linearity.

The main purpose of this article is to analyze the bifurcation, chaotic behaviors, and solitary wave solutions of the fractional Twin-Core couplers with Kerr law non-linearity by using the planar dynamical system method. This equation has profound physical significance and application value in the areas of optics and optical communication. Firstly, the traveling wave transformation is applied to convert the beta-derivative Twin-Core couplers with Kerr law non-linearity into the ordinary differential equations. Secondly, phase portraits and Poincaré sections of two-dimensional dynamical system and its perturbation system are plotted by using mathematical software. For different initial values, the planar phase diagram and three-dimensional phase diagram in red and blue are plotted, respectively. Finally, the solitary wave solutions of the fractional Twin-Core couplers with Kerr law non-linearity are obtained by using theory of planar dynamical system. In addition, three-dimensional graphs, two-dimensional graphs, and the contour graphs of the solitary wave solutions are drawn.

Analysis of fractional solitary wave propagation with parametric effects and qualitative analysis of the modified Korteweg-de Vries-Kadomtsev-Petviashvili equation.

This study explores the fractional form of modified Korteweg-de Vries-Kadomtsev-Petviashvili equation. This equation offers the physical description of how waves propagate and explains how nonlinearity and dispersion may lead to complex and fascinating wave phenomena arising in the diversity of fields like optical fibers, fluid dynamics, plasma waves, and shallow water waves. A variety of solutions in different shapes like bright, dark, singular, and combo solitary wave solutions have been extracted. Two recently developed integration tools known as generalized Arnous method and enhanced modified extended tanh-expansion method have been applied to secure the wave structures. Moreover, the physical significance of obtained solutions is meticulously analyzed by presenting a variety of graphs that illustrate the behaviour of the solutions for specific parameter values and a comprehensive investigation into the influence of the nonlinear parameter on the propagation of the solitary wave have been observed. Further, the governing equation is discussed for the qualitative analysis by the assistance of the Galilean transformation. Chaotic behavior is investigated by introducing a perturbed term in the dynamical system and presenting various analyses, including Poincare maps, time series, 2-dimensional 3-dimensional phase portraits. Moreover, chaotic attractor and sensitivity analysis are also observed. Our findings affirm the reliability of the applied techniques and suggest its potential application in future endeavours to uncover diverse and novel soliton solutions for other nonlinear evolution equations encountered in the realms of mathematical physics and engineering.

Unveiling the scope and perspectives of MOF-derived materials for cutting-edge applications.

Although synthesis and design of MOFs are crucial factors to the successful implementation of targeted applications, there is still lack of knowledge among researchers about the synthesis of MOFs and their derived composites for practical applications. For example, many researchers manipulate study results, and it has become quite difficult to quit this habit specifically among the young researchers Undoubtedly, MOFs have become an excellent class of compounds but there are many challenges associated with their improvement to attain diverse applications. It has been noted that MOF-derived materials have gained considerable interest owing to their unique chemical properties. These compounds have exhibited excellent potential in various sectors such as energy, catalysis, sensing and environmental applications. It is worth mentioning that most of the researchers rely on commercially available MOFs for use as precursor supports, but it is an unethical and wrong practice because it prevents the exploration of the hidden diversity of similar materials. The reported studies have significant gaps and flaws, they do not have enough details about the exact parameters used for the synthesis of MOFs and their derived materials. For example, many young researchers claim that MOF-based materials cannot be synthesized as per the reported instructions for large-scale implementation. In this regard, current article provides a comprehensive review of the most recent advancements in the design of MOF-derived materials. The methodologies and applications have been evaluated together with their advantages and drawbacks. Additionally, this review suggests important precautions and solutions to overcome the drawbacks associated with their preparation. Applications of MOF-derived materials in the fields of energy, catalysis, sensing and environment have been discussed. No doubt, these materials have become excellent class but there are still many challenges ahead to specify it for the targeted applications.

Solitonic solutions and stability analysis of Benjamin Bona Mahony Burger equation using two versatile techniques.

This study aims to explore the precise resolution of the nonlinear Benjamin Bona Mahony Burgers (BBMB) equation, which finds application in a variety of nonlinear scientific disciplines including fluid dynamics, shock generation, wave transmission, and soliton theory. Within this paper, we employ two versatile methodologies, specifically the extended exp ( - Ψ ( χ ) ) expansion technique and the novel Kudryashov method, to identify the exact soliton solutions of the nonlinear BBMB equation. The solutions we discovered involve trigonometric functions, hyperbolic functions, and rational functions. The uniqueness of this research lies in uncovering the bright soliton, kink wave solution, and periodic wave solution, and conducting stability analysis. Furthermore, the solutions' graphical characteristics were explored through the utilization of the mathematical software Maple 2022 ( https://maplesoft.com/downloads/selectplatform.aspx?hash=61ab59890f2313b2241fde3423fd975e ). The system's physical interpretation is defined through various types of graphs, including contour graphs, 3D-surface graphs, and line graphs, which use appropriate parameter values. These recommended techniques hold significant importance and are applicable in diverse nonlinear evolutionary equations found in the field of nonlinear sciences for illustrating nonlinear physical models.

Deciphering the Enigma of Neuron-Glial Interactions in Neurological Disorders.

Innate lymphocytes, including microglial cells, astrocytes, and oligodendrocytes, play a crucial role in initiating neuroinflammatory reactions inside the central nervous system (CNS). The prime focus of this paper is on the involvement and interplay of neurons and glial cells in neurological disorders such as Alzheimer's Disease (AD), Autism Spectrum Disorder (ASD), epilepsy, and multiple sclerosis (MS). In this review, we explore the specific contributions of microglia and astrocytes and analyzes multiple pathways implicated in neuroinflammation and disturbances in excitatory and inhibitory processes. Firstly, we elucidate the mechanisms through which toxic protein accumulation in AD results in synaptic dysfunction and deregulation of the immune system and examines the roles of microglia, astrocytes, and hereditary factors in the pathogenesis of the disease. Secondly, we focus on ASD and the involvement of glial cells in the development of the nervous system and the formation of connections between neurons and investigates the genetic connections associated with these processes. Lastly, we also address the participation of glial cells in epilepsy and MS, providing insights into their pivotal functions in both conditions. We also tried to give an overview of seven different pathways like toll-like receptor signalling pathway, MyD88-dependent and independent pathway, etc and its relevance in the context with these neurological disorders. In this review, we also explore the role of activated glial cells in AD, ASD, epilepsy, and MS which lead to neuroinflammation. Even we focus on excitatory and inhibitory imbalance in all four neurological disorders as imbalance affect the proper functioning of neuronal circuits. Finally, this review concludes that there is necessity for additional investigation on glial cells and their involvement in neurological illnesses.

Proceeding of catalytic water splitting on Cu/Ce@g-C3N4 photocatalysts: an exceptional approach for sunlight-driven hydrogen generation.

Increasing energy demands and environmental problems require carbon-free and renewable energy generation systems. For this purpose, we have synthesized efficient photocatalysts (i.e., g-C3N4, Cu@g-C3N4, Ce@g-C3N4 and Cu/Ce@g-C3N4) for H2 evolution from water splitting. Their optical, structural and electrochemical properties were investigated by UV-Vis-DRS, PL, XRD, FTIR, Raman and EIS methods. Their surface morphologies were evaluated by AFM and SEM analyses. Their chemical characteristics, compositions and stability were assessed using XPS, EDX and TGA techniques. Photoreactions were performed in a quartz reactor (150 mL/Velp-UK), whereas hydrogen generation activities were monitored using a GC-TCD (Shimadzu-2014/Japan). The results depicted that Cu/Ce@g-C3N4 catalysts are the most active catalysts that deliver 23.94 mmol g-1 h-1 of H2. The higher rate of H2 evolution was attributed to the active synergism between Ce and Cu metals and the impact of surface plasmon electrons (SPEs) of Cu that were produced during the photoreaction. The rate of H2 production was optimized by controlling various factors, including the catalyst amount, light intensity, pH, and temperature of the reaction mixture. It has been concluded that the current study holds promise to replace the conventional and costly catalysts used for hydrogen generation technologies.

Facile transfer of surface plasmon electrons of Au-NPs to Zn3V2O8 surfaces: a case study of sunlight driven H2 generation from water splitting.

For future energy perspectives, an effective way to produce H2 from water splitting is suggested using Zn3V2O8 photocatalyst as a semiconductor support. Further, to enhance the catalytic efficiency and stability of the catalyst, gold metal was deposited over the Zn3V2O8 surface by a chemical reduction method. For comparison, the Zn3V2O8 and gold-fabricated catalysts (i.e., Au@Zn3V2O8) were used for water splitting reactions. For structural and optical properties, various techniques, including XRD, UV-Vis DRS, FTIR, PL, Raman, SEM, EDX, XPS and EIS were used for the characterizations. The scanning electron microscope revealed the pebble-shaped morphology of the Zn3V2O8 catalyst. The FTIR and EDX results confirmed the purity and structural and elemental composition of the catalysts. Overall, 7.05 mmol g-1 h-1 H2 generation was observed over Au1.0@Zn3V2O8, which was ten times higher than bare Zn3V2O8. The results revealed that the higher H2 activities could be attributed to the Schottky barriers and surface plasmon electrons (SPRs). Thus the Au@Zn3V2O8 catalysts have potential to deliver higher hydrogen generation than Zn3V2O8 by water splitting.

Synergism of Co/Na in BiVO4 microstructures for visible-light driven degradation of toxic dyes in water.

In this work, we report a synergism of Co/Na in Co@Na-BiVO4 microstructures to boost the photocatalytic performance of bismuth vanadate (BiVO4) catalysts. A co-precipitation method has been employed to synthesize blossom-like BiVO4 microstructures with incorporation of Co and Na metals, followed by calcination at 350 °C. The structure and morphology of the as-prepared photocatalysts are characterized by XRD, Raman, FTIR, SEM, EDX, AFM, UV-vis/DRS and PL techniques. Dye degradation activities are evaluated by UV-vis spectroscopy, in which methylene blue, Congo red and rhodamine B dyes are chosen for comparative study. The activities of bare BiVO4, Co-BiVO4, Na-BiVO4, and Co@Na-BiVO4 are compared. To evaluate the ideal conditions, various factors that affect degradation efficiencies have been investigated. The results of this study show that the Co@Na-BiVO4 photocatalysts exhibit higher activity than bare BiVO4, Co-BiVO4 or Na-BiVO4. The higher efficiencies were attributed to the synergistic role of Co and Na contents. This synergism assists in better charge separation and more electron transportation to the active sites during the photoreaction.

Sensitive and discriminative detection of cysteine by a Nile red-based NIR fluorescence probe.

Cysteine (Cys) is a significant biological mercaptan that achieves key roles in several important physiological processes, such as reversible redox homeostasis in living organisms. Abnormal levels of Cys in the human body are directly related to many diseases. In this work, we constructed a sensitive sensor (Cys-NR) by connecting a Cys recognition group to a Nile red derivative. Due to photo-induced electron transfer (PET), the Cys-NR probe showed little fluorescence at 650 nm. With the addition of Cys to the assay solution, the chlorine unit of the probe was substituted by the thiol group of Cys. Further, the amino and sulfhydryl groups in cysteine underwent an intramolecular rearrangement, which led to the Cys-NR probe water solution turning from colorless to pink with an enhancement in fluorescence. The red fluorescence at 650 nm increased about 20 times. Based on the turn-on signal, a selective Cys detection method is developed. The probe signal is not affected by various potential interferences or other competing biothiols and the limit of detection (LOD) is determined to be 0.44 µM. In addition, the probe is further employed for imaging of Cys in live cells, revealing good biological imaging ability that could provide a new way of intracellular Cys detection.

Tunable sulphur doping on CuFe2O4 nanostructures for the selective elimination of organic dyes from water.

In this work, sulphur doped copper ferrites (S-CuFe2O4) photocatalysts were successfully synthesized for the first time using the facile hydrothermal method. The as-synthesized photocatalysts were characterized through XRD, Raman, TGA, FT-IR, UV-Vis-DRS, SEM, EDX and PL techniques. The results revealed that doping with sulphur has been found to be a suitable alternative that causes strain in the lattices as anions replace the oxygen from the CuFe2O4 nanostructures. Due to sulphur dopants, photocatalysts are able to efficiently trap and transfer the photoinduced charges, which readily suppress charge recombination. A UV-Vis spectrophotometer was used to monitor the degradation of selective toxic organic dyes (RhB, CR, MO, and CV) in aqueous media. The dye degradation results provide evidence for the surprisingly superior performance of S-CuFe2O4 over pristine CuFe2O4. On the basis of its efficiencies, this work can be assigned as an excellent candidate for photocatalysis science.

Growth of villi-microstructured bismuth vanadate (Vm-BiVO4) for photocatalytic degradation of crystal violet dye.

In this work, villi-microstructured Au-loaded BiVO4 photocatalysts were successfully synthesized by hydrothermal method. The as-synthesized photocatalysts were characterized by XRD, Raman, UV-Vis-DRS, PL, SEM and EDX techniques. The presence of metallic Au on the surface of Vm-BiVO4 support boosts the photocatalytic performance to degrade toxic crystal violet dye. The enhanced activities were attributed to the surface plasmon resonance (SPR) of Au which efficiently broadens the visible light response. SPR increases the electron population in Vm-BiVO4 and forms a Schottky barrier at the interface between Au and Vm-BiVO4 which enhances the separation efficiency of photoinduced charges. Various factors affecting photocatalytic degradation of crystal violet (CV) were studied to find optimum conditions. In addition, a radical trapping study indicates that ˙O2 - is the main active species in the degradation process of cationic CV dye. All photocatalytic degradation reactions were monitored by UV-Vis spectrophotometry (PerkinElmer/λ-365).

Determinants of vaccine coverage and timeliness in a northern Pakistani village.

The incidence of vaccine preventable disease in Pakistan remains high despite a long-standing Expanded Program on Immunization (EPI). We describe vaccine completeness, timeliness and determinants of coverage from a remote rural cohort (2012-2014). Vaccination histories were taken from EPI records. Vaccination was complete if all doses were received according to the EPI schedule and timely if doses were not ≥3 days early or ≥ 28 days late. Three models are presented: a multivariable logistic regression of household demographic and socioeconomic factors associated with complete vaccination, a multivariable mixed effects logistic regression assessing whether or not the vaccine was administered late (versus on-time), and a mixed effects multivariable Poisson regression model analysing the interval (in days) between vaccine doses. Of 959 enrolled children with full vaccination histories, 88.2 and 65.1% were fully vaccinated following either the pentavalent or DPT/HBV schedules if measles was excluded; coverage dropped to 50.0 and 27.1% when both doses of measles were included. Sixty-four (6.7%) were unvaccinated. Coverage and timeliness declined with subsequent doses. Migrating into the village after 1995 (95%CI 1.88 to 5.17) was associated with late vaccination. Being male, having an older father, and having parents with at least some formal education reduced the likelihood of a late dose. The interval between doses was consistent at 5 weeks (compared with the 4 weeks recommended by EPI). None of the socio-demographic variables were related to the likelihood of receiving full coverage. Vaccine coverage in Oshikhandass was higher than national averages. Measles vaccine coverage and timeliness were low; special consideration should be paid to this vaccine. The local vaccination schedule differed from the EPI, but the consistency suggests good local administration.

PIF7 controls leaf cell proliferation through an AN3 substitution repression mechanism.

Plants are agile, plastic organisms able to adapt to everchanging circumstances. Responding to far-red (FR) wavelengths from nearby vegetation, shade-intolerant species elicit the adaptive shade-avoidance syndrome (SAS), characterized by elongated petioles, leaf hyponasty, and smaller leaves. We utilized end-of-day FR (EODFR) treatments to interrogate molecular processes that underlie the SAS leaf response. Genetic analysis established that PHYTOCHROME-INTERACTING FACTOR 7 (PIF7) is required for EODFR-mediated constraint of leaf blade cell division, while EODFR messenger RNA sequencing data identified ANGUSTIFOLIA3 (AN3) as a potential PIF7 target. We show that PIF7 can suppress AN3 transcription by directly interacting with and sequestering AN3. We also establish that PIF7 and AN3 impose antagonistic control of gene expression via common cis-acting promoter motifs in several cell-cycle regulator genes. EODFR triggers the molecular substitution of AN3 to PIF7 at G-box/PBE-box promoter regions and a switch from promotion to repression of gene expression.

Examining the relationships between early childhood experiences and adolescent and young adult health status in a resource-limited population: A cohort study.

BACKGROUND: Adolescence is a critical point in the realization of human capital, as health and educational decisions with long-term impacts are made. We examined the role of early childhood experiences on health, cognitive abilities, and educational outcomes of adolescents followed up from a longitudinal cohort study in Pakistan, hypothesizing that early childhood experiences reflecting poverty would manifest in reduced health and development in adolescence. METHODS AND FINDINGS: Adolescents/young adults previously followed as children aged under 5 years were interviewed. Childhood data were available on diarrhea, pneumonia, and parental/household characteristics. New data were collected on health, anthropometry, education, employment, and languages spoken; nonverbal reasoning was assessed. A multivariable Bayesian network was constructed to explore structural relationships between variables. Of 1,868 children originally enrolled, 1,463 (78.3%) were interviewed as adolescents (range 16.0-29.3 years, mean age 22.6 years); 945 (65%) lived in Oshikhandass. While 1,031 (70.5%) of their mothers and 440 (30.1%) of their fathers had received no formal education, adolescents reported a mean of 11.1 years of education. Childhood diarrhea (calculated as episodes/child-year) had no association with nonverbal reasoning score (an arc was supported in just 4.6% of bootstrap samples), health measures (with BMI, 1% of bootstrap samples; systolic and diastolic blood pressure, 0.1% and 1.6% of bootstrap samples, respectively), education (0.7% of bootstrap samples), or employment (0% of bootstrap samples). Relationships were found between nonverbal reasoning and adolescent height (arc supported in 63% of bootstrap samples), age (84%), educational attainment (100%), and speaking English (100%); speaking English was linked to the childhood home environment, mediated through maternal education and primary language. Speaking English (n = 390, 26.7% of adolescents) was associated with education (100% of bootstrap samples), self-reported child health (82%), current location (85%) and variables describing childhood socioeconomic status. The main limitations of this study were the lack of parental data to characterize the home setting (including parental mental and physical health, and female empowerment) and reliance on self-reporting of health status. CONCLUSIONS: In this population, investments in education, especially for females, are associated with an increase in human capital. Against the backdrop of substantial societal change, with the exception of a small and indirect association between childhood malnutrition and cognitive scores, educational opportunities and cultural language groups have stronger associations with aspects of human capital than childhood morbidity.

Phytochrome regulates cellular response plasticity and the basic molecular machinery of leaf development.

Plants are plastic organisms that optimize growth in response to a changing environment. This adaptive capability is regulated by external cues, including light, which provides vital information about the habitat. Phytochrome photoreceptors detect far-red light, indicative of nearby vegetation, and elicit the adaptive shade-avoidance syndrome (SAS), which is critical for plant survival. Plants exhibiting SAS are typically more elongated, with distinctive, small, narrow leaf blades. By applying SAS-inducing end-of-day far-red (EoD FR) treatments at different times during Arabidopsis (Arabidopsis thaliana) leaf 3 development, we have shown that SAS restricts leaf blade size through two distinct cellular strategies. Early SAS induction limits cell division, while later exposure limits cell expansion. This flexible strategy enables phytochromes to maintain control of leaf size through the proliferative and expansion phases of leaf growth. mRNAseq time course data, accessible through a community resource, coupled to a bioinformatics pipeline, identified pathways that underlie these dramatic changes in leaf growth. Phytochrome regulates a suite of major development pathways that control cell division, expansion, and cell fate. Further, phytochromes control cell proliferation through synchronous regulation of the cell cycle, DNA replication, DNA repair, and cytokinesis, and play an important role in sustaining ribosome biogenesis and translation throughout leaf development.

Effect of metal atom in zeolitic imidazolate frameworks (ZIF-8 & 67) for removal of Pb2+ & Hg2+ from water.

Heavy metals especially lead (Pb) and mercury (Hg) are recognized as most emerging pollutants in underground water and are major threat to public health around the world. Major challenge to mitigate water pollution is construction of effective materials containing a host of deceivingly accessible high-density and high-level efficiency. Herein, we have synthesized two metal-organic frameworks (MOFs) with efficient porosity showing the right combination of structures. Representatively, ZIF-8 and ZIF-67 were designed by reacting Zn, Co salts with 2-methyl imidazole showing superior efficacy in removing Pb and Hg (1978.63&1436.11 mg/g respectively) from water. These adsorbents displayed high distribution values permitting them to quickly reduce concentration level of Pb2+, Hg2+ below permissible limit (Pb = 0-15 µg/L, Hg = 1-10 µg/L). EDX, FTIR analysis revealed that Pb2+, Hg2+ bound through weak interactions. Results presented here have shown extraordinary potential with high environmental remediation performance having 99.5% and 98.1% removal efficiency for lead & mercury respectively. Results revealed that adsorbents have same organic linker that identifies same morphology required for adsorption. The difference in adsorption capacity and porosity (ZIF-8 = 937&1370 m2/g, ZIF-67 = 1289&1889 m2/g) are deliberately caused due to presence of metal atoms having different electronic distribution, as cobalt in ZIF-67 and in case of ZIF-8 zinc metal.

Surface urban heat islands in the mega city of Karachi, their spatial distribution and health emergency response infrastructure.

The 2015 heat wave resulted in an estimated over 1200 deaths during the month of June. However, there were no records on the spatial distribution of the effects of this heat wave. An analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) daily data was conducted to identify regions that experienced above normal temperatures in 2015. An analysis of the monthly averages showed that in general April and May were the warmer months in Karachi, unlike the case in 2015. In addition, the general warm trends were common in the highly industrialised Sindh Industrial Trading Estate (SITE) and Liaquatabad towns, while Gadap, with its mostly barren land, and New Karachi also experience higher temperatures. Coastal towns were naturally cooler and more habitable in the given scenario. A count of the spatial presence of health facilities for the city was also extracted where Gadap and Korangi were poorly served while the more affluent towns of Defence Housing Authority (DHA) and Gulshan-e-Iqbal appeared to be better served.

Climatic and hydrological projections to changing climate under CORDEX-South Asia experiments over the Karakoram-Hindukush-Himalayan water towers.

The complex snow and glacier (cryosphere) dynamics over the "third pole" mountainous regions of the Karakoram-Hindukush-Himalayas (HKH) makes this region challenging for accurate hydrological predictions. The objective of this study is to investigate the impacts of climate change on major hydrological components (precipitation-runoff, snow- and glacier-runoff, evapotranspiration and inter-annual change in streamflows) over the Hunza-, Gilgit- and Astore-River basins, located in HKH. For this purpose, three different hydrological models (snowmelt runoff (SRM), HEC-HMS and HBV are tested over snow- and glacier-covered river basins. These are subsequently integrated with the climate projections simulated from regional climate models (RCMs) developed under CORDEX-SA experiments. The basin-wide RCM-simulations for future scenarios exhibited an increase in precipitation but decline in intensity of rise over high-altitude zones. The temperature rise showed a maximum increase during monsoon by 4.18 °C, 4.37 °C and 4.34 °C over Hunza-, Gilgit- and Astore-River basins, respectively, for the period 2071-2099 (2090s) and a high emission scenario (RCP8.5). Further, in response to rise in precipitation and temperature, the SRM simulations showed a significant increase in snow- glacier-melt runoff (49%, 42% and 46% for SRM) and precipitation runoff (23.8%, 15.7% and 27% for HEC-HMS) in the Hunza-, Gilgit- and Astore-River basins, respectively, for the 2090s under RCP8.5. The streamflow projections for SRM showed a shift in hydrological regime with an increase by 369 (168.4%), 216.5 (74.8%) and 131.8 m3/s (82%) during pre-monsoon in the Hunza-, Gilgit- and Astore-River basins, respectively and then decline by -73.2 m3/s (-13.9%) and -45.4 m3/s (23.4%) during monsoon of the 2090s, in the Hunza- and Astore-River basins, respectively, under RCP8.5. Overall, the projections show that the pre-monsoon and monsoon seasons are expected to be strongly influenced by climate change, through alterations in snow- and glacier-accumulation, and melt regimes with substantial consequences for river runoff in the region.

Benzo[ghi]perylene and coronene as ratiometric fluorescence probes for the selective sensing of nitroaromatic explosives.

A simple and efficient fluorometric sensing method is developed for the rapid detection of nitroaromatic explosives, based on the quenching of monomer and excimer emission of benzo[ghi]perylene and coronene. The ratiometric method (IE/IM) offers a linear response as a function of the concentration of picric acid (PA, i.e. 2,4,6-trinitrophenol), which is used as a model example of the nitroaromatic compounds (NOCs). The detection range is observed to be 0.1-120 µM of PA (22.9 ppb-27.5 ppm). The bright emission of the stable probe excimer and monomer can be easily distinguished under UV lamp from the quenched solution with nitro-aromatic molecules that enables naked-eye detection of nitro-aromatic explosives. The fluorescent paper strips prepared by embedding the probes on the surface of the paper are used for fast, portable and selective detection of NOCs. Our optimized methods can easily detect and quantify NOCs down to 0.1 µM. The sensing process is free of commonly encountered interferences such as volatile organic compounds (VOCs), acids, bases, oxygen, and salt solutions.

Black phosphorus nanosheets based sensitive protease detection and inhibitor screening.

Proteases, as one of the most significant kind of digestive enzymes, are closely related to a variety of physiological processes and diseases. Herein, a black phosphorus nanosheets (BPs) based sensitive fluorometric method for protease detection and inhibitor screening is proposed. The aqueous solution of perylene probe (probe 1) displays a strong fluorescence. BPs, as novel discovered two-dimensional (2D) materials, can adsorb probe 1 through electrostatic interactions, which causes fluorescence quenching of probe 1. Histone can control the interactions between the perylene probe and BPs, which can be further regulated by the introduction of a protease. Thus, the protease activity can be monitored by detecting the fluorescence intensity changes of probe 1. The method is label free, sensitive and selective. As low as 1 ng/mL trypsin can be easily detected.