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Background: Several conventional methods, including fungal culture and periodic acid-Schiff (PAS) reagent staining, have been used to diagnose oral candidiasis. The aim of this study was to evaluate the efficacy of a novel method, fungal fluorescent staining, in relation to conventional protocols in the diagnosis of oral candidiasis., Methods: We collected 106 oral swabs and 122 oral biopsy tissues from patients highly suspected with oral candidiasis. We applied fungal culture and periodic acid-Schiff reagent staining as the gold standard diagnostic tools. The efficacy of these methods in determining the presence of Candida was compared with that of fluorescent staining., Results: In the majority of specimens subjected to fluorescent staining, fungal organisms were distinguished by blue fluorescence surrounding their tubular or annular shapes. The sensitivity, specificity, Youden index, positive predictive value and negative predictive value of the fluorescent staining method were 82.7, 93.5, 76.7, 96.8 and 69.1% in oral swabs and 90.0, 92.9, 82.9, 96.0 and 82.9% in oral biopsy tissues, respectively., Conclusions: Fungal fluorescent staining represents a rapid method for detection of Candida, supporting its potential utility as an effective early diagnostic tool for oral candidiasis.

Multimodal imaging-the ability to acquire images of an object through more than one imaging mode simultaneously-has opened additional perspectives in areas ranging from astronomy to medicine. In this paper, we report progress toward combining optical and magnetic resonance (MR) imaging in such a "dual" imaging mode. They are attractive in combination because they offer complementary advantages of resolution and speed, especially in the context of imaging in scattering environments. Our approach relies on a specific material platform, microdiamond particles hosting nitrogen vacancy (NV) defect centers that fluoresce brightly under optical excitation and simultaneously "hyperpolarize" lattice [Formula: see text] nuclei, making them bright under MR imaging. We highlight advantages of dual-mode optical and MR imaging in allowing background-free particle imaging and describe regimes in which either mode can enhance the other. Leveraging the fact that the two imaging modes proceed in Fourier-reciprocal domains (real and k-space), we propose a sampling protocol that accelerates image reconstruction in sparse-imaging scenarios. Our work suggests interesting possibilities for the simultaneous optical and low-field MR imaging of targeted diamond nanoparticles.

The single signal amplification strategy is significant for detecting various disease biomarkers but is restricted by its limited accuracy. The multi-signal and multi-mode methods have overcome this deficiency. Acid phosphatase (ACP) is an important intracellular enzyme but one-step cell imaging material-based probes are scarce for ACP. Herein, we designed a one-step self-assembled polymer probe using neutral red (NR), modified-(pyridoxal-5′-phosphate (PLP)) and Eu3+. The polymer exhibited non-emission and excellent stability. Upon the catalytic hydrolysis reaction of ACP, the polymer exhibited two strong fluorescence signals at 373 nm and 613 nm and an appreciable decline of absorbance at 395 nm. The probe has excellent selectivity and higher sensitivity with a limit of detection as low as 0.02 mU mL−1. It possesses favorable biocompatibility and has been successfully used to detect and image intracellular ACP in several living cells. [ABSTRACT FROM AUTHOR]

Lymph node metastasis is a major metastatic route of cancer and significantly influences the prognosis of cancer patients. Radical lymphadenectomy is crucial for a successful surgery. However, iatrogenic normal organ injury during lymphadenectomy is a troublesome complication. Here, this paper reports a kind of organic nanoprobes (IDSe‐IC2F nanoparticles (NPs)) with excellent second near‐infrared (NIR‐II) fluorescence and photothermal properties. IDSe‐IC2F NPs can effectively label lymph nodes and helped achieve high‐contrast lymphatic imaging. More importantly, by jointly using IDSe‐IC2F nanoparticles and other kinds of nanoparticles with different excitation/emission properties, a multichannel NIR‐II fluorescence imaging modality and imaging‐guided lymphadenectomy is proposed. With the help of this navigation system, the iatrogenic injury can be largely avoided. In addition, NIR‐II fluorescence imaging‐guided photothermal treatment ("hot" strategy) can ablate those metastatic lymph nodes which are difficult to deal with during resection ("cold" strategy). Nanoprobes‐assisted and multichannel NIR‐II fluorescence imaging‐guided "cold" and "hot" treatment strategy provides a general new basis for the future precision surgery. [ABSTRACT FROM AUTHOR]

Mercury(II) ions have emerged as a widespread environmental hazard in recent decades. Despite different kinds of detection methods reported to sense Hg2+, it still remains a challenging task to develop new sensing molecules to replenish the fluorescence-based apparatus for Hg2+ detection. This communication demonstrates a novel fluorescent sensor using UiO-66-NH2 and a T-rich FAM-labeled ssDNA as a hybrid system to detect Hg2+ sensitively and selectively. To the best of our knowledge, it has rarely been reported that a MOF is utilized as the biosensing platform for Hg2+ assay. [ABSTRACT FROM AUTHOR]

Through harvesting of the increased Stokes shift of CdS QDs via Cu-doping, the concentration-quenching or aggregation-quenching of CdS QDs was largely alleviated. A dually-enriched strategy with both polyvinylpyrrolidone (PVP) twisting and SiO2 loading was developed for generating a highly luminescent doped-dots (d-dots) assembly for improved cell imaging. [ABSTRACT FROM AUTHOR]

It was found that the phosphorescence from denatured bovine serum albumin (dBSA)-capped Mn-doped ZnS QDs could be selectively quenched by Cr3+, and a phosphorescent probe for Cr3+ was thus developed. Based on phosphorescence decay as well as calculations of the relative energies of QDs and Cr3+, the mechanism for phosphorescent quenching was preliminarily ascribed to electron transfer from photo-excited Mn-doped ZnS QDs to Cr3+. Under the optimal conditions, good linear Stern–Volmer quenching was obtained for Cr3+ in the range of 10 to 300 nM. The limit of detection of this phosphorescence probe (3 nM) was 1 to 2 orders of magnitude lower than those of previously reported nanosensors, owing to the effective elimination of background fluorescence and scattering from the sample matrix. The analytical potential of the proposed probe was evaluated through determination of Cr3+ in water samples, with spike–recoveries ranging from 95 to 106%. [ABSTRACT FROM AUTHOR]

Development of the portable device is significant for sensitive and rapid detection of an anthrax biomarker dipicolinic acid (DPA), existing in the B. anthracis. In this work, a novel HAp:Tb-EDTA paper-based ratiometric fluorescent sensor was obtained by a simple one-pot method for rapid and sensitive DPA detection. With the increased DPA concentration, the luminescence intensity of HAp (hydroxyapatite) remained constant, and thus applied as the stable reference signal, while the luminescence signal of Tb3+-EDTA was significantly enhanced due to the antenna effect. Therefore, the HAp:Tb-EDTA paper-based sensor was endowed with self-calibrated and ratiometric fluorescent detection performance for DPA. The proposed sensor showed excellent detection performance with a detection limit as low as 10.8 nM in the linear range of 0.5–30 μM. After combination with a smartphone, rapid visual and fluorescent detection of DPA was achieved. The proposed sensor was successfully applied to detect DPA from B. subtilis spore real samples, showing the application prospects of the paper-based sensors and opening a new horizon to develop novel paper-based point-of-care testing (POCT) devices. A sensing platform was constructed by a HAp:Tb-EDTA paper-based ratiometric fluorescent probe prepared by a one-pot method and combined with a smartphone. The sensing platform has good stability and can be used for sensitive detection of DPA released from Bacillus subtilis spores. [Display omitted] • A novel HAp:Tb-EDTA paper-based ratiometric fluorescent probe was facilely constructed. • The Tb3+-EDTA recognition unit uniformly distributed on HAp with a paper-like structure, making it superior to that based on commercial test papers. • A portable platform was constructed through combining with smartphones for real samples detection, showing widespread application prospects. • Opening a new horizon to develop novel paper-based point-of-care testing (POCT) devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuNCs modified with dual-ligand with high fluorescence and stability were prepared. • Cys-PVP-CuNCs were found to have a specific fluorescence response to Sn4+. • The LOD could reach 5 μg L−1 by observing the fluorescence color change with naked eye. • The proposed probe is simple, portable, stable, selective and highly sensitive. In this study, polyvinylpyrrolidone (PVP) supported and cysteine (Cys) modified copper nanoclusters (Cys-PVP-CuNCs) with high fluorescence intensity have been synthesized and used to establish a simple and sensitive assay for the determination of trace Sn4+. The presence of Sn4+ can lead to fluorescence quenching based on the aggregation of PVP-CuNCs caused by the coordination of Sn4+ and oxygen atoms. For Cys-PVP-CuNCs, the ligand Cys can transfer electrons to the metal center of the cluster, resulting in strong fluorescence enhancement of CuNCs and intensification of fluorescence quenching after interaction with Sn4+, which is conducive to more sensitive visual detection. The proposed assay allows for the detection of Sn4+ in a linear range from 5 μg L−1 to 100 μg L−1, with a detection limit as low as 4.5 μg L−1 at a signal-to-noise ratio of 3. Moreover, under UV light, the obvious fluorescent color change can be observed by naked eyes at Sn4+ concentration ranging from as low as 5 μg L−1 to 200 μg L−1. Benefiting from the high sensitivity of this assay, satisfactory test results have been obtained when using only 10 mg of canned food samples with rapid digestion. The proposed Cys-PVP-CuNCs fluorescent probe shows excellent stability, simple operation, good selectivity, and high sensitivity, and thus it is expected to be used in the real-time field detection of Sn4+. [ABSTRACT FROM AUTHOR]

It is important to identify and detect ions as they are essential in the life system. The development of fluorescent sensors with easy-to-prepare and high sensitivity has always been a topic of widespread concern. Herein, an easily prepared fluorescent sensor based on bis-(naphthyl acetyl)-hydrazone (BNH) was successfully synthesized. Remarkably, the BNH exhibits blue aggregation-induced emission (AIE) fluorescence. The blue fluorescence of BNH was quenched by the addition of Fe3+, and then enhanced by the addition of F− and H 2 PO 4 −, while the fluorescence opened by F− was quenched again by Al3+. The LODs (limits of lowest detection) of BNH for Fe3+ is 4.46 × 10−7 M. This study provides a simple and feasible AIE fluorescence sensor synthesis method for efficient and sensitive detecting Fe3+, F− and H 2 PO 4 −. [Display omitted] • An easy-to-prepare fluorescence sensor BNH could relay recognition of Fe3+, F− and H 2 PO 4 −. • The BNHs show blue aggregation-induced emission (AIE) fluorescence. • The BNH selectively detect Fe3+ by collaboration of cation-π and coordination interactions. • BNH–Fe 3+ selectively detect F−and H 2 PO 4 − via competitive coordination interaction. • High selective, other cations could not interfere the Fe3+ detecting process. [ABSTRACT FROM AUTHOR]

The green fluorescence of Tb@COF can be quickly turned on by the target antibiotic (norfloxacin) with an efficient sensitization of Tb3+ via the antenna effect, and in the presence of red emitting Ru(bpy) 3 2+, the multi-color fluorescence sensing platform from red to green can be realized, with a smartphone for improved visual monitoring of norfloxacin. [Display omitted] • A multicolor change from red to green was achieved using Ln@COF and triggered by NOR. • The sensor showed a rapid response (within 1 min) and high visual sensitivity to NOR. • The method was highly sensitive for NOR (limit of detection of 7.3 nM). • Visual detection of NOR in real-world samples was realized using a smartphone. Sensitive and visual determination of fluoroquinolone antibiotics (FQs) is of great significance since their abuse and inappropriate handling can be problematic. Herein, we propose a lanthanide covalent organic framework fluorescence sensing system (Tb@COF-Ru) with visualization capability to determine the FQs level, where Tb@COF was employed as the sensing probe, while the red-emitting Ru(bpy) 3 2+ serves as a constant red fluorescent background. With increasing norfloxacin concentration, the green fluorescence of Tb3+ is gradually enhanced, finally realizing the multicolor fluorescence change from red to green. With a smartphone for RGB analysis, visual monitoring and quantitative analysis were realized without any sophisticated instrument. Limits of detection for the fluorescence quantitative and visual mode for norfloxacin were 0.33 nM and 7.3 μM, respectively. This method was rapid (1 min) and visualized, providing a simple analysis of various food matrices (honey, milk, egg and beef) and water samples for trace FQs. [ABSTRACT FROM AUTHOR]

Nano-hydroxyapatite particles (Ca 10 (PO 4 ) 6 (OH) 2 , nano-HAp), the main inorganic components of human bone and teeth, has attracted much attentions as a kind of biocompatible carrier to construct dual/multi modal bioimaging probes in recent years. However, the currently developed HAp-based probes still have some shortcomings, such as poor mono-dispersion, potential toxicity and none near-infrared emission, which hinder their further applications in the field of bioimaging. In order to solve the above problems and to combine the high space resolution of CT and high sensitivity of fluorescence together, here we developed a novel dual-modal (CT/fluorescence) bioimaging probe based on nano-HAp. Ba 2 + as a CT contrast agent was doped into the lattice of nano-HAp, and Cu-doped quantum dots with near-infrared fluorescent emission and hyaluronic acid (HA) were conjugated with the HAp as a fluorescent agent and tumor-targeting ligand individually to realize its near-infrared imaging and tumor-targeting. The as-received Ba 2 + -doped HAp-QDs-HA conjugates not only well maintained the good dispersion of nano-HAp, but also possessed near-infrared emission at about 700 nm, good biocompatibility and photostability. Furthermore, the in-vitro CT and fluorescence cell imaging of the conjugates also exhibited good dual-modal bioimaging and tumor-targeting ability for potential applications in the field of early diagnosis and therapy of cancer. [ABSTRACT FROM AUTHOR]

In view of our research interests in stimuli-responsive supramolecular functional materials and ion recognition, a novel organogelator based on naphthalimide (NA) was successfully synthesized via a 3-step pathway. The obtained gelator NA could serve as a supramolecular π-gel(ONA) in 1,2-Propanediol by a series of self-assembly driving forces, which showed bright blue aggregation-induced emission (AIE). Interestingly, the organogel ONA showed a fluorescence "turn-off" for Fe3+ in the gel-gel state. Furthermore, the Fe3+ coordinated organogel Fe-ONA could detect H 2 PO 4 −successively in fluorescence spectrum. The fluorescence responding circles "on–off–on" could be performed 4 times when alternating the addition of Fe3+ and H 2 PO 4 − to ONA. The bonding mechanisms between supramolecular organogel (ONA) and ions were detected by a series of characterization. Even more significantly, the supramolecular gel ONA can be used to adsorb Fe3+ from aqueous media and the adsorption percentage of ONA xerogel for Fe3+ ions can reach up to 92.26%. [Display omitted] • The gelator molecular NA could self-assemble to form a π-gel with aggregation induced emission(AIE) in 1,2-Propanediol. • The fluorescence responding circle could be repeated 4 times by the sequential addition of Fe3+ and H 2 PO 4 −. • The supramolecular gel ONA can be used to adsorb Fe3+ from aqueous media and detect Fe3+ in practical samples. [ABSTRACT FROM AUTHOR]

Graphene-enhanced Raman scattering (GERS) has attracted much attention recently. In present study, monolayer of chemically reduced graphene oxide (RGO) nanosheets was chemically bonded on Si substrates and their possible applications in Raman scattering were investigated. In comparison with the mechanically exfoliated graphene, mildly reduced graphene oxide (MR-GO) monolayer is a better substrate to quench the fluorescence (FL) signals and simultaneously enhance the Raman signals of adsorbed Rhodamin 6G (R6G) molecules. Raman and X-ray photoelectron spectra indicate that π–π stacking and the residual polarized oxygen groups on MRGO surface, which can produce a strong local electric field under laser excitation, are mainly responsible for the excellent GERS effect of MR-GO substrate, while the charge transfer between R6G and MR-GO has a relatively low contribution for GERS effect. Our results not only provide a new approach to realize sensitive GERS substrate, but also are helpful for improving the fundamental understanding of GERS effect on RGO substrate. [ABSTRACT FROM AUTHOR]

A novel acylhydrazone-based fluorescent sensor G has been successfully synthesized to achieve ultrasensitive detection of Pd2+ in water. Compound G is composed of gallic acid derivatives and biphenyl by acylhydrazone group, which formed a suspension and promote intermolecular self-assembly in DMF by π-π stacking, van der Waals forces and intermolecular hydrogen bonds, leading to the formation of stable supramolecular organogels OG in DMF by the gel factor G. And the supramolecular organogels OG realized ultra-sensitive detection of Pd2+ in water via fluorescence quenching at 475 nm. The LOD for Pd2+ for the chemosensor G is 2.03 × 10−8 M and the resulting metal gel PdG can also recognize H 2 OP 4 − among the various anions by fluorescence spectroscopy. And the sensing mechanism of chemosensor G and metal ions has been studied through a series of characterization methods including FE-SEM, FT-IR, XRD, 1H NMR titrations and XPS, with the results indicating that the π-π stacking and hydrogen bond were broken during the addition of the cation. A novel acylhydrazone-based fluorescent sensor G has been successfully synthesized to achieve ultrasensitive detection of Pd2+ in water. Compound G is composed of gallic acid derivatives and biphenyl by acylhydrazone group, which formed a suspension and promote intermolecular self-assembly in DMF by π-π stacking, van der Waals forces and intermolecular hydrogen bonds, leading to the formation of stable supramolecular organogels OG in DMF by the gel factor G. And the supramolecular organogels OG realized ultra-sensitive detection of Pd2+ in water via fluorescence quenching at 475 nm. The LOD for Pd2+ for the chemosensor G is 2.03 × 10−8 M and the resulting metal gel PdG can also recognize H 2 OP 4 − among the various anions by fluorescence spectroscopy. And the sensing mechanism of chemosensor G and metal ions has been studied through a series of characterization methods including FE-SEM, FT-IR, XRD, 1H NMR titrations and XPS, with the results indicating that the π-π stacking and hydrogen bond were broken during the addition of the cation. Unlabelled Image • Fluorescent sensor G is synthesized of gallic acid derivatives and biphenyl. • The gel factor G could form stable supramolecular organogels OG in DMF. • Fluorescence sensor G achieved ultra-sensitive detection toward Pd2+ in water. • The LOD for Pd2+ for the chemosensor G is 2.03 × 10−8 M. • The resulting metal gel PdG can recognize H 2 OP 4 − among the various anions. [ABSTRACT FROM AUTHOR]