Room-Temperature Band-Aligned Infrared Heterostructures for Integrable Sensing and Communication.

The demand for miniaturized and integrated multifunctional devices drives the progression of high-performance infrared photodetectors for diverse applications, including remote sensing, air defense, and communications, among others. Nonetheless, infrared photodetectors that rely solely on single low-dimensional materials often face challenges due to the limited absorption cross-section and suboptimal carrier mobility, which can impair sensitivity and prolong response times. Here, through experimental validation is demonstrated, precise control over energy band alignment in a type-II van der Waals heterojunction, comprising vertically stacked 2D Ta2NiSe5 and the topological insulator Bi2Se3, where the configuration enables polarization-sensitive, wide-spectral-range photodetection. Experimental evaluations at room temperature reveal that the device exhibits a self-powered responsivity of 0.48 A·W-1, a specific directivity of 3.8 × 1011 cm·Hz1/2·W-1, a response time of 151 µs, and a polarization ratio of 2.83. The stable and rapid photoresponse of the device underpins the utility in infrared-coded communication and dual-channel imaging, showing the substantial potential of the detector. These findings articulate a systematic approach to developing miniaturized, multifunctional room-temperature infrared detectors with superior performance metrics and enhanced capabilities for multi-information acquisition.

A near-infrared fluorescent probe for tracking endogenous and exogenous H2O2 in cells and zebrafish.

H2O2 is an important signaling molecule in the body, and its levels fluctuate in many pathological sites, therefore, it can be used as a biomarker for early diagnosis of disease. Since the environment in vivo is extremely complex, it is of great significance to develop a probe that can accurately monitor the fluctuation of H2O2 level without interference from other physiological processes. Based on this, we designed and synthesized two new near-infrared H2O2 fluorescent probes, LTA and LTQ, based on the ICT mechanism. Both of them have good responses to H2O2, but LTA has a faster response speed. In addition, the probe LTA has good biocompatibility, good water solubility, and a large Stokes shift (95 nm). The detection limit is 4.525 µM. The probe was successfully used to visually detect H2O2 in living cells and zebrafish and was successfully used to monitor the changes in H2O2 levels in zebrafish due to APAP-induced liver injury.

Visualize intracellular ß-galactosidase using an asymmetric near-infrared fluorescent probe with a large Stokes shift.

ß-galactosidase (ß-Gal) is an important biomarker of cell senescence and primary ovarian cancer. Therefore, it is of great significance to construct a near-infrared fluorescent probe with deep tissue penetration and a high signal-to-noise ratio for visualization of ß-galactosidase in biological systems. However, most near-infrared probes tend to have small Stokes shifts and low signal-to-noise ratios due to crosstalk between excitation and emission spectra. Using d-galactose residues as specific recognition units and near-infrared dye TJ730 as fluorophores, a near-infrared fluorescence probe SN-CR with asymmetric structure was developed for the detection of ß-Gal. The probe has a fast reaction equilibrium time (<12 min) with ß-Gal, excellent biocompatibility, near-infrared emission (738 nm), low detection limit (0.0029 U/mL), and no crosstalk between the excitation spectrum and emission spectrum (Stokes shifts 142 nm) of the probe. Cell imaging studies have shown that SN-CR can visually trace ß-Gal in different cells and distinguish ovarian cancer cells from other cells.

Design and application of prodrug fluorescent probes for the detection of ovarian cancer cells and release of anticancer drug.

Ovarian cancer is a gynecologic malignancy with high mortality. The main reason is that it is detected at an advanced stage due to a lack of early diagnosis and treatment. Therefore, it is of great interest to develop a chemical tool that can visualize ovarian cancer cells in real-time and eliminate them. Unfortunately, probes that can simultaneously monitor both modes of action for the diagnosis and treatment of ovarian cancer have not been developed. Here, we designed a novel prodrug fluorescent probe (YW-OAc) that not only visually tracks cancer cells but also enables the on-demand delivery of chemotherapeutic agents. By ß-Gal-mediated glycosidic bond hydrolysis, the fluorescent signal changed from blue to green (signal 1), enabling visual tracking of ovarian cancer cells. Subsequently, the identified cancer cells were subjected to precise light irradiation to induce anticancer drug release accompanied by a fluorescence transition from green to blue (signal 2), enabling real-time information on drug release. Thus, the prodrug fluorescent probe YW-OAc provides comprehensive two-step monitoring during cancer cell recognition and clearance. Notably, YW-OAc exhibited high affinity (Km = 3.74 µM), high selectivity, and low detection limit for ß-Gal (0.0035 U/mL). We also demonstrated that YW-OAc can visually trace endogenous ß-Gal in different cells and exhibit high phototoxicity in ovarian cancer cells. We hope that the prodrug fluorescent probe YW-OAc, can be used as an effective tool for biomedical diagnosis and treatment.

Rational design of near-infrared ratiometric fluorescent probes for real-time tracking of ß-galactosidase in vivo.

ß-Galactosidase (ß-gal) is a hydrolytic enzyme in lysosomes and is also an important biomarker of cellular senescence and primary ovarian cancer. Therefore, real-time non-invasive detection of ß-gal activity in vivo is of great significance for the prevention of cell senescence and early diagnosis of ovarian cancer. We designed an enzyme-activated proportional near-infrared (NIR) probe (Gal-Br-NO2) for real-time fluorescence quantification and capture of ß-gal activity in vivo. The main characteristics of the Gal-Br-NO2 probe include short response time (less than 10 min), large Stokes displacement (155 nm), and near-infrared fluorescence emission (670 nm). The probe has also been successfully used to detect ß-gal in ovarian cancer cells and senile cells and can accurately detect endogenous ß-gal in zebrafish. Our work provides a potential tool for pre-clinical real-time tracking of ß-gal activity in vivo and early diagnosis of disease.

Near-infrared fluorescent probe with a large Stokes shift for bioimaging of ß-galactosidase in living cells and zebrafish develop at different period.

Overexpression of ß-galactosidase (ß-gal) in tumor cells may serve as a valuable biomarker for the early diagnosis of some cancers (such as ovarian cancer). In addition, abnormal accumulation of ß-gal is also considered an essential marker of cell senescence. Therefore, it is important to construct fluorescent probes with excellent fluorescence properties to visualize ß-gal in biological systems. Here, we designed and screened a novel fluorescent probe XM for the detection of ß-gal. Spectral data show that the probe has a good affinity (Km = 2.6 µM) for ß-gal, large stokes shift (190 nm), fast response speed (stable within 20 min), and low detection limit (6.7 × 10-3 U/mL). Based on the above advantages, XM can not only detect ß-gal content in cancer cells but also track the changes of ß-gal content in zebrafish at different developmental period. We believe XM will become a powerful tool for the early cancer diagnosis and cellular senescence.

Fast and sensitive near-infrared ratiometric fluorescent probe with a self-immolative spacer for imaging of endogenous alkaline phosphatase activity in cells and in vivo.

Alkaline phosphatase (ALP), a vital hydrolase widely distributed in organisms, is regarded as a critical biomarker strongly associated with many physiological and pathological processes. Therefore, fast and efficient detection of ALP activity in vivo is of great value for clinical diagnosis. Herein, a novel near-infrared (NIR) ratiometric fluorescent probe (HP) was designed based on ESIPT for trapping ALP activity in cells and in vivo. Notably, incorporating a self-immolative spacer dramatically reduces the response time (8.5 min) of HP. Moreover, the probe exhibits excellent water solubility, large Stokes shift (147 nm), the ratiometric determination of ALP at 570 nm and 689 nm, low detection limit (3.98 U L-1). More importantly, the probe was also successfully applied to detect and monitor variations in endogenous ALP activity in zebrafish due to the drug (APAP) induced organ damages.

Acetyl group assisted rapid intramolecular recognition of hydrogen peroxide: A novel promising approach for efficient hydrogen peroxide probe.

As a vital biomolecule, hydrogen peroxide (H2O2) is involved in many physiological and pathological processes. Therefore, it is important to detect H2O2 in vivo conveniently and efficiently. In this paper, we report a new method of nucleophilic addition of H2O2 to the acetyl group to promote the rapid intramolecular reaction, which can be used to develop an efficient H2O2 probe. Based on this unique auxiliary recognition part, a fluorescent probe for H2O2 detection was designed and synthesized. This probe has the advantages of high sensitivity (limits of detection 7.0 × 10-8 M or even lower.), fast response (within 3 min) and large Stokes shift (225 nm), which not only can monitor exogenous and endogenous H2O2 in cells but also successfully achieves the change of endogenous H2O2 level caused by drug sexual organ injury in zebrafish.

A susceptible multifunctional fluorescent probe based on levulinic acid for the practical detection of SO2.

Sulfites (HSO3-) are used as preservatives and additives in many foods and medicines. However, a high sulfite concentration can cause asthma attacks and even breathing difficulties. Sulfites can also accumulate from the environment into the body, so it is necessary to develop a probe capable of detecting SO2 in the environment and in organisms. A multifunctional sensor, SO-2, based on levulinic acid was designed and synthesized. SO-2 showed an excellent response to SO2 with a detection limit of 2.0 × 10-8 M and a fast response equilibrium time (within 10 min), which indicated that the probe could detect SO2 with high sensitivity. The probe also successfully traced exogenous bisulfite in cells and was applied to analyze water samples in a natural environment.

Novel ratiometric fluorescent probe for real-time detection of alkaline phosphatase and its application in living cells.

A novel ratiometric fluorescent probe has been developed through a simple synthetic route for the detection of alkaline phosphatase(ALP) in aqueous media and for fluorescence imaging in living cells. The introduction of a spontaneous-degradation spacer in the design of the fluorescent probe is beneficial for the ratio detection method and allows the selection of a fluorophore with an amino group. Under catalysis by ALP, the phosphate monoester bond breaks; this is followed by 1,4-elimination, decomposition of the carbamate moiety, and subsequent formation of the 4-amine-1,8-naphthalimide fluorophore. The probe APN shows a significant fluorescence colour change from blue to green in response to ALP, and the fluorescence intensity ratio of the probe solution (F550/F480) has a good linear relationship with the ALP concentration in the range of 0 to 100 U L-1. Our studies have demonstrated that APN exhibits high accuracy in recognising ALP, with a detection limit as low as 0.16 U L-1. Furthermore, the probe shows very good biocompatibility, which is beneficial for its application in biological systems.

Energy-Saving Electrospinning with a Concentric Teflon-Core Rod Spinneret to Create Medicated Nanofibers.

Although electrospun nanofibers are expanding their potential commercial applications in various fields, the issue of energy savings, which are important for cost reduction and technological feasibility, has received little attention to date. In this study, a concentric spinneret with a solid Teflon-core rod was developed to implement an energy-saving electrospinning process. Ketoprofen and polyvinylpyrrolidone (PVP) were used as a model of a poorly water-soluble drug and a filament-forming matrix, respectively, to obtain nanofibrous films via traditional tube-based electrospinning and the proposed solid rod-based electrospinning method. The functional performances of the films were compared through in vitro drug dissolution experiments and ex vivo sublingual drug permeation tests. Results demonstrated that both types of nanofibrous films do not significantly differ in terms of medical applications. However, the new process required only 53.9% of the energy consumed by the traditional method. This achievement was realized by the introduction of several engineering improvements based on applied surface modifications, such as a less energy dispersive air-epoxy resin surface of the spinneret, a free liquid guiding without backward capillary force of the Teflon-core rod, and a smaller fluid-Teflon adhesive force. Other non-conductive materials could be explored to develop new spinnerets offering good engineering control and energy savings to obtain low-cost electrospun polymeric nanofibers.

A novel colorimetric and far-red emission ratiometric fluorescent probe for the highly selective and ultrafast detection of hypochlorite in water and its application in bioimaging.

Hypochlorous acid (HOCl)/hypochlorite (OCl-), an important reactive oxygen species, plays a number of important roles in various physiological processes. However, abnormal levels of OCl- can cause many serious diseases, such as atherosclerosis, rheumatoid arthritis, cardiovascular disease, and cancer. The development of efficient methods to monitor OCl- in biological systems is therefore of particular importance. Thus, we herein report a novel isophorone-based fluorescent probe, i.e., DCOH-FR-OCl, for OCl- detection. This probe was found to exhibit colorimetric and far-red ratiometric fluorescence response signals, excellent selectivity and sensitivity for OCl- (detection limit, 88.06 nM), a remarkably large Stokes shift (158 nm), an ultrafast response (completed within 3 s), perfect photostability, and good water solubility (100% in aqueous media). DCOH-FR-OCl, as we know, is the first probe that can detect OCl- by using two different response signals at an ultrafast speed with a large Stokes shift in fully aqueous media. Furthermore, DCOH-FR-OCl can be successfully employed in the real-time imaging of endogenous and exogenous OCl- in living cells.

Near-infrared ratiometric probe with a self-immolative spacer for rapid and sensitive detection of alkaline phosphatase activity and imaging in vivo.

Alkaline phosphatase (ALP), an enzyme that catalyzes the hydrolysis of phosphate groups, is closely associated with many diseases, including bone disease, prostate cancer, and diabetes. Thus, new assays for ALP detection in live cells are needed to better understand its role in related biological processes. In this study, we constructed a novel near-infrared ratiometric fluorescent probe for detecting ALP activity with high sensitivity. The probe uses a new self-immolative mechanism that can achieve a rapid response (within 10 min) to ALP, detected as a spectral shift (from 580 to 650 nm). This method effectively avoids issues related to instrument variability, and the near-infrared fluorescence emission (650 nm) makes it more suitable for biological detection. Moreover, the high sensitivity (14-fold enhancement of the fluorescence ratio F650/F580) and low detection limit (0.89 U L-1) for ALP allows the probe to be adapted to complex biological environments. The assay was successfully performed using serum samples with a linear range of ALP of up to 150 U L-1. We used the developed probe to detect and image endogenous ALP in cells with satisfactory results, and we successfully used the probes to detect changes in endogenous ALP levels in zebrafish caused by drug-induced organ damage.

A near-infrared fluorescent probe for the ratiometric detection and living cell imaging of ß-galactosidase.

ß-Galactosidase (ß-gal) has captured the attention of biologists, chemists, and medical researchers as an important biomarker for cell senescence and primary ovarian cancer. Therefore, many fluorescent probes with visible light emission have been developed for the detection and imaging of ß-gal in living cells. However, near-infrared (NIR) ratiometric probes are more suitable for bioimaging because near-infrared light can effectively avoid the interference of autofluorescence and the ratiometric approach can improve sensitivity and accuracy of the detection. In this work, we designed an NIR ratiometric probe (TMG) for the highly sensitive detection of ß-gal. Using a spontaneous degradation mechanism based on the ICT effect, the change in ratio (F650/F580) exhibited a prominent ß-gal-dependent performance and proved a strong linear response to the activity of ß-gal at an enzyme concentration between 0 and 200 U L-1, with a limit of detection as low as 0.86 U L-1, and the response speed is much faster than the same type of probes previously reported. The probe also revealed an excellent biocompatibility and a large Stokes shift. Moreover, fluorescence microscopy imaging experiments confirmed that this probe could be successfully used for the detection of endogenous ß-gal in living cells. Graphical abstract.

A highly selective and ultrafast near-infrared fluorescent turn-on and colorimetric probe for hypochlorite in living cells.

Hypochlorous acid (HOCl)/hypochlorite (OCl-), important reactive oxygen species, play essential roles in many physiological and pathological progresses. Accordingly, we developed a novel dicyanomethylene-4H-pyran (DCM)-based probe DCM-OCl for colorimetric and near-infrared fluorescent turn-on detection of OCl-. The probe exhibited excellent selectivity and sensitivity for OCl- over other bio-related analytes with a detection limit of 80 nM. The excellent selectivity of DCM-OCl for OCl- was ascribed to specific oxidative cleavage of the dimethylthiocarbamate (DMTC) recognition unit by OCl-. Moreover, DCM-OCl exhibited an ultrafast turn-on response (<3 s) to OCl-, potentially allowing real-time detection of OCl-. Furthermore, DCM-OCl was successfully used to image endogenous/exogenous OCl- in living cells.

Novel fluorescent probe for rapid and ratiometric detection of ß-galactosidase and live cell imaging.

ß-Galactosidase (ß-gal) is an important biomarker for primary ovarian cancers and cell senescence; however, a fast response fluorescent probe for ratiometric monitoring is still rare. A novel, ratiometric water-soluble fluorescent probe (FLM) for ß-gal was developed. The emission ratio F550/F450 reached the maxima at about 5 min and can be used for real-time detection of ß-gal; the ratio gained an ultimate enhancement of about 260-fold. The ratio (F550/F450) displayed brilliant ß-gal-dependent performance and responded linearly with ß-gal activity. The probe showed wonderful biocompatibility and was successfully used for the bioimaging of endogenous ß-gal in the human ovarian cancer cell line OVCAR-3.

Ratiometric fluorescent probes with a self-immolative spacer for real-time detection of ß-galactosidase and imaging in living cells.

Ratiometric fluorescent probes with a self-immolative spacer for ß-galactosidase (ß-gal) were developed. They function by ß-gal-cleaving the ß-galactoside bond of fluorescent substrates, followed by self-immolation to liberate the amino group of fluorophore. Thus, a remarkable variation in the photophysical properties was observed and the corresponding ratiometric detection of ß-gal was realized. Our studies demonstrated that the GNPN exhibited high sensitivity for recognition of ß-gal, with a detection limit as low as 0.17 U L-1. GNPN can rapidly quantify ß-gal enzyme activity; the emission ratio F545/F475 for the GNPN reached maxima after approximately 4 min, which was one of the shortest response time ever reported. Furthermore, we demonstrated that these probes possess excellent biocompatibility and can be used to visualize the endogenous ß-gal in ovarian cancer cells.

Cobalt-Catalyzed Enantioselective Negishi Cross-Coupling of Racemic α-Bromo Esters with Arylzincs.

The first cobalt-catalyzed enantioselective Negishi cross-coupling reaction, and the first arylation of α-halo esters with arylzinc halides, are disclosed. Employing a cobalt-bisoxazoline catalyst, various α-arylalkanoic esters were synthesized in excellent enantioselectivities and yields (up to 97 % ee and 98 % yield). A diverse range of functional groups, including ether, halide, thioether, silyl, amine, ester, acetal, amide, olefin and heteroaromatics is tolerated by this method. This method was suitable for gram-scale reactions, enabling the synthesis of (R)-xanthorrhizol with high enantiopurity. Radical clock experiments support the intermediacy of radicals.

Arylation of Azaarylmethylamines with Aryl Chlorides and a NiBr2/NIXANTPHOS-based Catalyst.

A nickel-catalyzed coupling of azaarylmethylamines with aryl chlorides has been achieved. NIXANTPHOS together with low cost NiBr2 was successfully developed and optimized to exhibit high reactivity at 2.5 mol % loading. Under optimized reaction conditions, aryl(azaaryl)methylamine products were afforded in good to excellent yields (22 examples, up to 98% yield).

Direct enantioseparation of nitrogen-heterocyclic pesticides on cellulose-based chiral column by high-performance liquid chromatography.

The enantiomeric separation of eight pesticides including bitertanol (), diclobutrazol (), fenbuconazole (), triticonazole (), imazalil (), triapenthenol (), ancymidol (), and carfentrazone-ethyl () was achieved, using normal-phase high-performance liquid chromatography on two cellulosed-based chiral columns. The effects of isopropanol composition from 2% to 30% in the mobile phase and column temperature from 5 to 40 °C were investigated. Satisfactory resolutions were obtained for bitertanol (), triticonazole (), imazalil () with the (+)-enantiomer eluted first and fenbuconazole () with the (-)-enantiomer eluted first on Lux Cellulose-2 and Lux Cellulose-3. (+)-Enantiomers of diclobutrazol () and triapenthenol () were first eluted on Lux Cellulose-2. (-)-Carfentrazone-ethyl () were eluted first on Lux Cellulose-2 and Lux Cellulose-3 with incomplete separation. Reversed elution orders were obtained for ancymidol (7). (+)-Ancymidol was first eluted on Lux Cellulose-2 while on Lux Cellulose-3 (-)-ancymidol was first eluted. The results of the elution order at different column temperatures suggested that column temperature did not affect the optical signals of the enantiomers. These results will be helpful to prepare and analyze individual enantiomers of chiral pesticides.