Blue Dots Research Articles

LB7. Ad26.COV2.S-Elicted Neutralizing Activities Against SARS-CoV-2 Variants of Concern in Phase 1/2a and Phase 3 Clinical Trials

BackgroundIn a Phase 3 trial, the Janssen COVID-19 vaccine, Ad26.COV2.S, showed robust efficacy against severe–critical COVID-19 in countries where different SARS-CoV-2 variants were circulating. We evaluated Ad26.COV2.S-elicited antibody neutralizing activity against variants of concern (VOC) B.1.1.7 (Alpha), B.1.351 (Beta), and B.1.617.2 (Delta) in sera from participants in clinical trials following a single dose of Ad26.COV2.S.MethodsNeutralizing activities of Ad26.COV2.S (given at a dose level of 5 x 1010 viral particles [vp]) against VOC were assessed by wild-type virus neutralizing (wtVNA) and pseudovirion neutralization (psVNA) assays in sera from participants in Phase 1/2a and Phase 3 clinical trials, respectively. Geometric mean titers (GMTs) were determined at Days 29 and 71 after vaccination.ResultsIn serum samples from Phase 1/2a participants (n = 6), at Day 29 after 1 dose of Ad26.COV2.S, wtVNA titers against VOC were lower than for the original strain (GMT = 573), with GMT = 65, 14, and 15 for Alpha, Beta, and Delta, respectively, representing 8.8-, 40.9-, and 37.7-fold decreases. By Day 71 after vaccination (n = 14), fold differences between the original strain (GMT = 375) and VOC (GMT = 113, 27, and 28) were smaller (3.3-, 13.9-, and 13.4-fold) than at Day 29, suggestive of B-cell maturation (Figure 1). Day 71 titers against the Delta variant were maintained for at least 8 months following a single dose of Ad26.COV2.S (5 x 1010 vp). In serum samples from Phase 3 participants (n = 8), psVNA titers against VOC were lower than the original strain at Day 71 after vaccination, with the lowest titers observed for the Beta variant (3.6-fold decrease vs original strain). Smaller reductions in Nab titers for VOC were observed in the psVNA assay compared to wtVNA.Figure 1. Neutralization of B.1.1.7 (Alpha), B.1.351 (Beta), and B.1.617.2 (Delta) lineages in serum samples from participants who received Ad26.COV2.S. n = 6 samples at Day 29 and n = 14 (n = 14 for Alpha and Beta; n = 6 for Delta, comprising the same 6 participants at Day 29) samples at Day 71 after vaccination with a single dose of Ad26.COV2.S (5 x 10^10 vp dose level) were analyzed in wild-type virus neutralization assays against the SARS-CoV-2 Victoria strain (D614, black dots), the B.1.1.7 (Alpha; green dots) the B.1.351 (Beta; blue dots), and the B.1.617.2 (Delta; purple dots) lineages. Dots represent the IC50 (inhibitory concentration) titers per participant. Geometric mean titers (GMTs) and fold decrease in neutralizing activity between the original Victoria strain and each lineage are shown. ConclusionAd26.COV2.S-elicited serum neutralizing activity against VOC showed an overall decrease in titers relative to the original strain that was largest for the Beta variant, even though vaccine efficacy against severe–critical COVID-19 was maintained in countries where these variants were circulating versus in countries where they were not circulating. Over time, titers against variants increased, suggesting B-cell affinity maturation leading to increasing coverage of VOC.Disclosures Mathieu Le Gars, n/a, Johnson & Johnson (Employee, Shareholder) Jerald Sadoff, MD, Johnson & Johnson (Employee, Shareholder) Mandy Jongeneelen, n/a, Johnson & Johnson (Employee, Shareholder) Dirk Heerwegh, n/a, Janssen Research and Development (Employee) Georgi Shukarev, MD, Janssen (Employee) Carla Truyers, n/a, Janssen Research and Development (Employee) Anne Marit de Groot, n/a, Johnson & Johnson (Employee) Gert Scheper, n/a, Johnson & Johnson (Employee, Shareholder) Jenny Hendriks, n/a, Johnson & Johnson (Employee, Shareholder) Boerries Brandenburg, n/a, Johnson & Johnson (Employee, Shareholder) Frank Struyf, n/a, Johnson & Johnson (Employee, Shareholder) Johan Van Hoof, n/a, Johnson & Johnson (Employee, Shareholder) Macaya Douoguih, MD, MPH, Janssen (Employee) Hanneke Schuitemaker, PhD, Johnson & Johnson (Employee, Shareholder)

A Facile Microwave-Assisted Green Synthetic Approach of Solid-State Fluorescent Carbon-Dot Nanopowders Derived from Biowaste for Potential Latent-Fingerprint Enhancement

Latent fingerprint detection and visualization remains a challenge especially where problems of poor contrast, auto-fluorescent surfaces and patterned backgrounds are encountered. As a result there is an increasing interest in the development of simple, cost effective, rapid and yet accurate methods for latent fingerprint detection and recovery. Herein, this paper reports the synthesis of bright blue photoluminescent carbon dots (C-dots) via an eco-friendly and simple one-step microwave-assisted carbonization of potato peels’ biomass. The C-dots were prepared in only 3 min and ground into powder and used without any further treatment. The as-prepared C-dots were characterized using atomic force microscope, Fourier transform infra-red spectroscopy and X-ray diffraction with an average size of 1.0[Formula: see text]nm. The optical properties of the as-prepared C-dots were studied by UV-Vis spectroscopy and spectrofluorometer which established an excitation and emission wavelengths of 390[Formula: see text]nm and 480[Formula: see text]nm, respectively. Owing to their strong solid state fluorescence, the as-prepared C-dots’ powder was successfully used in latent fingerprint detection and imaging on porous and nonporous surfaces. Latent fingerprints were recovered with high resolution and excellent quality providing sufficient details for individual identification. These findings demonstrate that C-dots derived from biomass have a great potential in latent fingerprint analysis for forensic applications.

Carbon dots and gold nanoclusters assisted construction of a ratiometric fluorescent biosensor for detection of Gram-negative bacteria

A core-satellite nanocomposite was prepared by encapsulating the photostable blue carbon dots (BCDs) in the core of silica as the reference signal readout, and the target-sensitive gold nanoclusters (AuNCs) covalently linked to the surface of silica as the respond signal readout. The nanocomposite (BCD@SiO2@AuNC) was used as a ratiometric fluorescent sensor to realize the selective detection of Gram-negative bacteria. The detection principle was based on the quenching of Cu2+ toward AuNCs and the reduction of Gram-negative bacteria toward Cu2+. The sensor exhibited good selectivity toward Gram-negative bacteria owing to the copper-homeostasis mechanism possessed by the bacteria. The sensor demonstrated linear response to the logarithm concentration of Gram-negative bacteria with determination coefficients higher than 0.912. The feasibility of the sensor was verified by analysis of Gram-negative bacteria in eggshell, swimming pool water, as well as Chinese cabbage samples with recoveries ranging from 93.9% to 109%.

Paper-Based Test for Rapid On-Site Screening of SARS-CoV-2 in Clinical Samples.

Detection methods for monitoring infectious pathogens has never been more important given the need to contain the spread of the COVID-19 pandemic. Herein we propose a highly sensitive magnetic-focus-enhanced lateral flow assay (mLFA) for the detection of SARS-CoV-2. The proposed mLFA is simple and requires only lateral flow strips and a reusable magnet to detect very low concentrations of the virus particles. The magnetic focus enhancement is achieved by focusing the SARS-CoV-2 conjugated magnetic probes in the sample placed in the lateral flow (LF) strips for improved capture efficiency, while horseradish peroxidase (HRP) was used to catalyze the colorimetric reaction for the amplification of the colorimetric signal. With the magnetic focus enhancement and HRP-based amplification, the mLFA could yield a highly sensitive technology for the recognition of SARS-CoV-2. The developed methods could detect as low as 400 PFU/mL of SARS-CoV-2 in PBS buffer based on the visible blue dots on the LF strips. The mLFA could recognize 1200 PFU/mL of SARS-CoV-2 in saliva samples. With clinical nasal swab samples, the proposed mLFA could achieve 66.7% sensitivity and 100% specificity.

Two new species of the marine flatworm Pericelis (Platyhelminthes: Polycladida) from southwestern Japan with an amendment of the generic diagnosis based on phylogenetic inference

ABSTRACT We describe two new polyclad species, Pericelis lactea sp. nov. and P. maculosa sp. nov., from Japan. Pericelis lactea sp. nov. is characterized by (i) a translucent white body, (ii) the male and female gonopores opening separately and (iii) a conical penis papilla. Pericelis maculosa sp. nov. is distinguished from its other congeners by (i) a translucent white body with white to light blue dots all over the dorsal surface and brown speckles around the pharyngeal area, (ii) the male and female gonopores opening separately and (iii) a long, cylindrical penis papilla. We also infer the phylogeny of 10 species of Diposthidae using a concatenated dataset comprising partial 18S and 28S rDNA sequences from the two new and eight other known species. Our results showed Marcusia alba Cuadrado, Rodríguez, Moro, Grande and Noreña, 2021 was nested within a clade comprising the seven Pericelis species included in the analysis. These findings support the prior synonymization of Marcusia with Pericelis based on the morphology, hence we transferred M. alba to Pericelis. We modified the diagnosis of Pericelis to accommodate such species as P. alba comb. nov. and P. lactea sp. nov., in which marginal eyespots are distributed only anteriorly. http://zoobank.org/urn:lsid:zoobank.org:pub:14906638-970B-4C67-81EE-E6111F98F77F

Application of computer-generated images to train pattern recognition used in semiquantitative immunohistochemistry scoring.

This study aimed to clarify whether the pattern recognition involved in scoring proliferation fractions can be trained by abstract computerized images of virtual tissues. Twenty computer-generated images with randomly distributed blue or red dots were scored by 12 probands (all co-workers or collaborators of the Institute of Pathology, University of Bonn). Afterward, the probands underwent a training phase during which they received an immediate feedback on the actual rate of positivity after each image. Finally, the initial testing series was rescored. In a second round with 15 different probands, 20 Ki-67 immunohistochemistry images of tonsil tissue were scored, followed by the same training phase with computer-generated images, before the immunohistochemistry slides were scored again. Paired t-tests were used to compare the differences in mean rates pre- and post-training. Concerning computerized images, untrained probands scored the percentages of positive dots with a mean deviation from the true rates of 8.2%. Following training, the same testing series was scored significantly better with a mean deviation of 4.9% (mean improvement 3.3%, p < 0.001). Scoring real immunohistochemistry slides, the training with computerized images also improved correct estimations, albeit to a lesser degree (mean improvement 1%, p = 0.03). Abstract computerized images of virtual tissues may be a useful tool to train and improve the accuracy of pattern recognition involved in semiquantitative scoring of immunohistochemistry slides. As a side results, this study highlights the value of computer-generated images to verify the performance of image-analysis software.

Late Effects after Treatment in Mantle Cell Lymphoma: No Difference By Intensity of First-Line Regimens with or without Autologous Stem Cell Transplantation

PurposeThe improved survival for mantle cell lymphoma (MCL) patients calls for updated knowledge about long-term adverse effects of treatment. We recently showed that younger MCL patients (≤65 years of age) selected for rituximab-cytarabine containing regimens and a consolidating high-dose chemotherapy with stem cell transplantation (HD-ASCT) had a 42% reduced all-cause mortality compared to patients selected for less intensive regimens with rituximab-bendamustine and/or rituximab-CHOP based treatment without HD-ASCT (non-HD-ASCT) (Blood Advances 2021, PMID: 3371034). The aim here was to describe long-term side-effects and outcome from these different treatment strategies.MethodsWe conducted a population-based cohort study including all Swedish MCL patients diagnosed between 2000 and 2014, and 1:10 matched comparators. First, transplantation-related mortality and acute side effects (within 60 days of HD-ASCT) were described. Next, for the analysis of late effects, we took a landmark approach with follow-up starting at 12 months after diagnosis (i.e., assuming treatment completion). Hazard ratios with 95% confidence intervals (CIs) of first hospital visit/admission/death due to a specific disease group (based on ICD chapters) were estimated using Cox regression models, comparing the rates among HD-ASCT and non-HD-ASCT patients to those among the comparators. Additionally, the 5-year cumulative incidence of death due to MCL, other malignancy, cardiovascular disease, or remaining causes was described for both patient treatment groups (HD-ASCT and non-HD-ASCT) and comparators.ResultsA total of 620 MCL patients were included with a median follow-up from diagnosis of 4.1 years (range: 0-15.7). In total, 280 (45%) received HD-ASCT (median age 58, range 32-69) and 340 (55%) R-CHOP/R-Bendamustin and non-HD-ASCT (median age 65, range 22-69). Four out of 280 (1.5%) HD-ASCT treated patients died within 60 days of their transplantation. Acute side effects of transplantation were mainly infections and diseases of the circulatory or digestive systems.In relation to the 6,200 matched comparators (median age 63, range 22-70) the rate of hospital visits/admissions/death after 12 months was significantly higher among MCL patients (irrespective of treatment intensity) for neoplasms (excluding MCL), other blood disorders, infections, respiratory, genitourinary, digestive, and skin disorders (Figure 1A). Patients treated with HD-ASCT did not experience a higher rate of late effects than those treated without HD-ASCT, for any of the disease groups (Figure 1A).The 5-year cumulative incidence of MCL-specific death in HD-ASCT treated patients was 0.23 (95% CI: 0.18-0.30) and 0.32 (95% CI: 0.26-0.38) in non-HD-ASCT treated patients (Figure 1B). Fatal long-term (≥12 months) side effects were rare in HD-ASCT treated patients, and the absolute majority of MCL patients died from their lymphoma and not from a complication.ConclusionsMCL patients have a higher risk of long-term complications than comparators particularly in the disease groups respiratory disorder, blood disorders (other than MCL) and infections. Intensive first-line treatment including HD-ASCT was however associated with a similar rate of long-term side-effects in all disease groups as among patients selected for less intensive treatments and non-HD-ASCT. Hence, given the previously shown favourable long-term survival associated with HD-ASCT, it appears that this treatment should not be avoided based on fear of neither fatal acute side effects nor more long-term side effects. Instead symptomatic lymphoma disease and death from the lymphoma seem to drive the majority of long-term health problems in MCL patients regardless of treatment intensity.Figure 1. A) Hazard ratios for hospital visits/admissions/deaths due to specific disease groups (based on ICD chapters) among MCL patients and comparators, stratified by treatment with consolidative autologous stem cell transplant (ASCT) or (non-ASCT). All models were adjusted for age at diagnosis, sex, calendar year of diagnosis, and Charlson comorbidity index. Grey dots; comparators, blue dots MCL patients (non-ASCT-treated) and red dots MCL patients (ASCT treated) B) Cumulative incidence of death due to MCL, other malignancies, cardiovascular disease (CVD), and other causes among MCL patients without (upper panel) and with (lower panel) ASCT. [Display omitted] DisclosuresEkberg: Jansen-Cilag: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support. Smedby: Jansen-Cilag: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support. Albertsson-Lindblad: Jansen-Cilag: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support. Jerkeman: Jansen-Cilag, AbbVie, Gilead, Celgene: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support, Research Funding. Weibull: Jansen-Cilag: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support. Glimelius: Jansen-Cilag: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support.

Recent Advances in Blue Perovskite Quantum Dots for Light-Emitting Diodes.

Metal halide perovskite nanostructures have sparked intense research interest due to their excellent optical properties. In recent years, although the green and red perovskite light-emitting diodes (PeLEDs) have achieved a significant breakthrough with the external quantum efficiency exceeding 20%, the blue PeLEDs still suffer from inferior performance. Previous reviews about blue PeLEDs focus more on 2D/quasi-2D or 3D perovskite materials. To develop more stable and efficient blue PeLEDs, a systematic review of blue perovskite quantum dots (PQDs) is urgently demanded to clarify how PQDs evolve. In this review, the recent advances in blue PQDs involving mixed-halide, quantum-confined all-bromide, metal-doped and lead-free PQDs as well as their applications in PeLEDs are highlighted. Although several excellent PeLEDs based on these PQDs have been demonstrated, there are still many problems to be solved. A deep insight into the advantages and disadvantages of these four types of blue-emitting PQDs is provided. Then, their respective potential and issues for blue PeLEDs have been discussed. Finally, the challenges and outlook for efficient and stable blue PeLEDs based on PQDs are addressed.

Preparation of blue luminescence gold quantum dots using laser ablation in aromatic solvents

Preparation of blue luminescence gold quantum dots using laser ablation in aromatic solvents

Ionic liquid assisted pure blue emission CsPbBr3 quantum dots with improved optical properties and alkyl chain regulated stability

Stability issue of blue emitting CsPbX3 quantum dots (QDs) remains a great challenge for their application in optoelectronic devices. In this work, hydrophobic ionic liquids (ILs) 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (NTf2) were used to obtain blue emission CsPbBr3 QDs with high color purity featured with a 16 nm full width at half-maximum (FWHM). Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results elucidated ILs formed effective passivation on QDs through stronger interaction with surface Pb2+ compared to OA/OAm. This passivation effect led to the enhancement of photoluminescence quantum yields (PLQYs) from 33% for the pristine sample to 51% for QDs modified by ILs. And the stability of the modified QDs was enhanced by keeping the blue emitting even after 32 h UV irradiation. More interestingly, there is an alkyl chain effect existed that QDs with longer alkyl chain ILs exhibit better stability than the ones with shorter alkyl chains. It may relate to the higher hydrophobicity originated from long alkyl chain. Resultantly, Warm white light emitting diode (WLED) based on the IL-contained QDs was fabricated which qualified with a Commission Internationale de L'Eclairage (CIE) color coordinates of (0.33,0.35), Correlated color temperature (CCT) of 5416 K and maximum luminance of 9062.9 cd/m2. The demonstrated ILs passivation strategy might be an effective method for preparing blue emitting perovskite QDs with high PLQYs and stability.

USP7 and VCPFAF1 define the SUMO/Ubiquitin landscape at the DNA replication fork.

SummaryThe AAA+ ATPase VCP regulates the extraction of SUMO and ubiquitin-modified DNA replication factors from chromatin. We have previously described that active DNA synthesis is associated with a SUMO-high/ubiquitin-low environment governed by the deubiquitylase USP7. Here, we unveil a functional cooperation between USP7 and VCP in DNA replication, which is conserved from Caenorhabditis elegans to mammals. The role of VCP in chromatin is defined by its cofactor FAF1, which facilitates the extraction of SUMOylated and ubiquitylated proteins that accumulate after the block of DNA replication in the absence of USP7. The inactivation of USP7 and FAF1 is synthetically lethal both in C. elegans and mammalian cells. In addition, USP7 and VCP inhibitors display synergistic toxicity supporting a functional link between deubiquitylation and extraction of chromatin-bound proteins. Our results suggest that USP7 and VCPFAF1 facilitate DNA replication by controlling the balance of SUMO/Ubiquitin-modified DNA replication factors on chromatin.

The chloride anion doped hybrid perovskite quantum dots exchanged by short surfactant ligand enable color-tunable blue fluorescent emitting for QLEDs application

The facile approach combined the halide mixture of chloride and bromide anions with the exchange of short-chain ligand Phenethylamine (PEA) was used to prepare hybrid perovskite PEA-MAPbBr3-xClx quantum dots (PEA-QDs-Cl), which realized blue emissive quantum dots light-emitting diode (QLED) with wider gamut of Commission Internationale de l’Eclairage (CIE) coordinates (Δx = −0.04, Δy = 0.03) than National Television Systems Committee (NTSC) TV color standard. Compared to pristine MAPbBr3 quantum dots (pristine-QDs) prepared by conventional long-chain ligands, the size of PEA-QDs-Cl was manipulated from 9 nm to 3 nm characterized by HRTEM, emissive spectra were blue shifted from 528 nm to 469 nm measured by photoluminescence (PL). Meanwhile, time-resolved PL (TRPL) decay lifetimes of perovskite quantum dots doped with chloride anions (QDs-Cl) were improved from 10.3 ns to 13.9 ns, because short-chain ligands were introduced to passivate defects on the surface of QDs-Cl. Furthermore, XPS results showed that the chloride content was decreased from 34.7% to 33.7% through chloride vacancies on the surface of QDs-Cl were passivated by PEA.

Heterostructural tailoring of blue ZnSeTe quantum dots toward high-color purity and high-efficiency electroluminescence

Ternary ZnSeTe quantum dots (QDs) are regarded as the most promising non-Cd blue emitters, which can be exploited for the fabrication of self-emissive QD display device or QD-light-emitting diode (QLED). We report extensive synthesis of high-quality blue ZnSeTe QDs with a double shell scheme of ZnSe inner and ZnS outer shell in a unique two-step approach. In such ZnSeTe/ZnSe/ZnS heterostructure, the thickness modulation of ZnSe inner shell leads to the variations in not only the thickness of ZnS outer shell but Photoluminescence (PL) characteristics such as peak wavelength, color purity-associated bandwidth, and Quantum yield (QY). The Te/Se ratio in ZnSeTe core is precisely tailored to demonstrate moderate PL tunability in deep-blue territory and the thickness of ZnS outer shell is further independently varied to examine its effects on the performance of QLED. All the QDs that possess outstanding PL QYs up to near-unity (96%) along with an appropriate deep-blue emissivity are individually employed for solution-processed QLED fabrication. The resulting blue QLEDs produce high electroluminescence performances in the ranges of 6107–12654 cd/m2 in luminance and 5.3–18.6% in external quantum efficiency, depending on ZnSe inner, ZnS outer shell dimensions and ZnSeTe core composition.

Intrinsic anisotropy parameters of a series of lanthanoid complexes deliver new insights into the structure-magnetism relationship

Intrinsic anisotropy parameters of a series of lanthanoid complexes deliver new insights into the structure-magnetism relationship

Synthesis of narrow blue emission gradient ZnSeS quantum dots and their quantum dot light-emitting diode device performance

The performance of blue quantum dot light-emitting diode (QD-LED) device as one of the three primary color sources still lag behind that of red and green QD-LEDs. In this study, to obtain highly brightness, excellent color purity, and environmentally friendly blue-light-emitting materials for next generation display applications, we designed and synthesized ZnSeS quantum dots (GCS-QDs) from core Se–S composition-gradient to shell, in which the majority of Se resides close to the core domain and S dominantly locates outmost of the shells. The final GCS-QDs had a high quantum yield value of 78%, significantly narrow spectrum width of 12 nm, and reached an emission peak at 445 nm. Moreover, the blue-emitting QD-LED were fabricated by employing the GCS-QDs as light emitter, and the resulting device exhibited maximum brightness of 3,359 cd/m2, maximum current efficiency of 1.2 cd/A, maximum external efficiency of 3.5%, and full width at half maximum of only 16 nm at 448 nm).

An optical sensing system with ratiometric and turn-off dual-mode of CDs@MnO2 nanosheets for the determination of H2O2 and glucose based on a combination of first-order scattering, fluorescence, and second-order scattering

The optical sensor with ratiometric and turn-off dual modes is constructed to detect H2O2 and glucose based on blue fluorescent carbon dots (CDs) and MnO2 nanosheets with great ability of fluorescence quenching and scattering. Employing CDs@MnO2 nanosheets nanocomposite as the probe, H2O2 is detected by simultaneously collecting first-order scattering (FOS, 353.5 nm), fluorescence (440 nm), and second-order scattering (SOS, 710 nm) under the excitation of 350 nm. H2O2 with strong oxidation property can etch the lamellar structure of MnO2 nanosheets into nano-fragments, which made the fluorescence of CDs in the system recover and the scattering intensity (FOS and SOS) of the system decrease significantly. Therefore, the optical sensor combined FOS and fluorescence signals in ratiometric mode, and SOS signal in turn-off mode to realize sensitive determination of H2O2. The linear ranges of ratiometric mode and turn-off mode for H2O2 detection were 0.2–40 and 0.2–15 μM, respectively. And the limits of detection (LODs) of two modes were 73 and 104 nM, respectively. Furthermore, the sensor was also successfully applied to the detection of glucose which can react to produce H2O2. Satisfactorily, the LODs of this sensor for glucose detection were 95 and 113 nM for ratiometric mode and turn-off mode, respectively. This work not only provides a new method for the accurate detection of H2O2 and glucose, but also extends a new idea for the study of the combination of scattering and fluorescence.

A ratiometric fluorescent probe based on carbon dots assembly for intracellular lysosomal polarity imaging with wide range response

Lysosomal polarity is considered a key indicator of lysosomal function due to its significant impact on membrane fluidity and enzymatic reactions in lysosomes. Monitoring lysosomal polarity can gain insight into the related physiological and pathological processes and develop new diagnostic methods. However, current fluorescent probes with lysosomal polarity response suffer from narrow linear range, photobleaching and complicated preparation. Herein, a ratiometric fluorescent probe (r-bCDs) for intracellular lysosomal polarity imaging is designed and constructed by amide bond assembly of polarity-sensitive red fluorescent carbon dots (rCDs) and referenced blue fluorescent carbon dots (bCDs). r-bCDs show a much wider linear range of polarity response (orientation polarizability Δf from 0.020 to 0.315) than other probes, and the interference of uneven distribution and instrument factors can be effectively eliminated by ratiometric fluorescent sensing. Imaging of intracellular lysosomal polarity with r-bCDs is implemented to observe the polarity variation caused by the change of cell state and the difference between cancer cells and normal cells. This work provides a promising tool for studying the related physiological and pathological processes and developing new diagnostic methods.

Oil-water self-assembly engineering of Prussian blue/quantum dots decorated graphene film for wearable textile biosensors and photoelectronic unit

Integrating functional components into graphene film is crucial for taking full advantage of graphene and manufacturing film-based devices. However, most graphene film-based system acts specialized property with complicated fabricated process, limiting further application. Herein, a highly compatible graphene nanofilm, decorated by electroactive Prussian blue (PB) and photoelectric responsive quantum dots (QDs), has been prepared via a simple and effective oil-water (O/W) self-assembly engineering. Interestingly, this graphene film could be transferred on various substrates for flexible application. As a result, PB and QDs have played a synergic effect with reduced graphene oxide (rGO) matrix, respectively, acquiring both excellent electrochemical sensing behaviors and extremely enhanced photocurrent generation compared with pure QDs film under simulated solar light. Furthermore, impressive biosensing performance has been obtained by enzyme-modified PB-rGO-QDs film. Additionally, proposed film-based wearable textile H2O2 sensor possesses high sensitivity of 53.8 µA mM−1 cm−2, while developed wearable glucose biosensor exhibits good performance, with a sensitivity of 37.24 µA mM−1 cm−2. Significantly, wearable devices of PB-rGO-QDs films on textile have established flexible bending lifetime over thousands of cycles, accompanying with stable sensor and photoelectronic properties. Prospectively, PB-rGO-QDs films would provide an efficient strategy of multi-components self-assembly for broadening the application of graphene and developing wearable biosensing/photoelectronic devices.

A Smartphone-Based Fluorescent Electronic Tongue for Tracing Dopaminergic Agents in Human Urine.

The importance of tracing dopaminergic agents in the progression assessment of Parkinson's disease has boosted the demand for fast, sensitive, and real-time multi-analyte detection. Herein, visual and fingerprint fluorimetric patterns have been created by an optical sensor array to simultaneously detect and discriminate among levodopa, carbidopa, benserazide, and entacapone, as important dopaminergic agents. A dual emissive nanoprobe consisting of red quantum dots and blue carbon dots with an overall pink emission has been fabricated to provide unique emission patterns in the presence of the target analytes. The sensor elements in the array come from it's differential response in the absence and presence of cetyltrimethylammonium bromide under alkaline conditions. A smartphone camera was used to take photos from the solutions in the wells. Distinct changes in the spectral profiles along with vivid and concentration-dependent color variations led to visual discrimination of dopaminergic agents in a broad concentration range. The results of linear discriminant analysis revealed great discrimination accuracies. Different concentrations of the target analytes were excellently recognized in human urine. The high sensitivity of the array, which is a bonus to rapid, on-site, and visual discrimination of dopaminergic agents, holds great promise for routine analysis of real-world clinical samples.

A novel ratiometric fluorescent probe for water content in ethanol and temperature sensing

In this paper, two tetrahydo[5]helicene-based dyes (THH1 and THH2) were studied on their twist intramolecular charge transfer. And the water-soluble blue carbon dots (N-CDs) were synthesized. Considering that their different optical propeties, the ratiometric fluorescence probes N-CDs/THH1 and N-CDs/THH2 were constructed by mixing N-CDs and dyes simply. It was found that N-CDs/THH1 and N-CDs/THH2 could quickly and sensitively detect water content in ethanol, with linear range of 0.500–25.0 vol% and 0.500–30.0 vol%, respectively. What’s more, through the actual sample test, it showed that the detection had good accuracy and precision. At the same time, it was found that two ratiometric probes could also be applied to the thermometry with good reversibility based on optical temperature sensors.