Highly Active Coreactant-Capped and Water-Stable 3D@2D Core-Shell Perovskite Quantum Dots as a Novel and Strong Self-Enhanced Electrochemiluminescence Probe

Self-enhanced electrochemiluminescence (ECL) probes have attracted more and more attention in analytical chemistry for their significant simplification of the ECL sensing operation while improving the ECL sensing sensitivity. However, the development and applications of self-enhanced ECL probes are still in their infancy and mainly suffer from the requirement of a complicated synthesis strategy and relatively low self-enhanced ECL activity. In this work, we took advantage of the recently emerged perovskite quantum dots (PQDs) with high optical quantum yields and easy surface engineering to develop a new type of PQD-based self-enhanced ECL system. The long alkyl chain (C18) diethanolamine (i.e., N-octadecyldiethanolamine (ODA)) with high ECL coreactant activity was selected as a capping ligand to synthesize an ODA-capped PQD self-enhanced ECL probe. The preparation of the coreactant-capped PQDs is as simple as for the ordinary oleylamine (OAm)-capped PQDs, and the obtained ODA-capped PQDs exhibit very strong self-enhanced ECL activity, 82.5 times higher than that of traditional OAm-capped PQDs. Furthermore, the prepared ODA-PQDs have a unique nanostructure (ODA-CsPbBr3@CsPb2Br5), with the highly emissive 3D CsPbBr3 PQD as the core and the water-stable 2D CsPb2Br5 as the shell, which allows ODA-PQDs to be very stable in aqueous media. It is envisioned that the prepared ODA-3D@2D PQDs with the easy preparation method, strong self-enhanced ECL, and excellent water stability have promising applications in ECL sensing.

Deteriorated bone microarchitecture caused by sympathetic overstimulation in pheochromocytoma and paraganglioma

PURPOSE

Despite the potentially destructive effect of sympathetic activity on bone metabolism, its impact on bone microarchitecture, a key determinant of bone quality, has not been thoroughly investigated. This study aims to evaluate the impact of sympathetic activity on bone microarchitecture and bone strength in patients with pheochromocytoma and paraganglioma (PPGL).

METHODS

A cross-sectional study was conducted in 38 PPGL patients (15 males and 23 females). Bone turnover markers serum procollagen type 1 N-terminal propeptide (P1NP) and β-carboxy-terminal crosslinked telopeptide of type 1 collagen (β-CTX) were measured. 24-h urinary adrenaline (24hUE) and 24-h urinary norepinephrine levels (24hUNE) were measured to indicate sympathetic activity. High-resolution peripheral quantitative computed tomography (HR-pQCT) was conducted to evaluate bone microarchitecture in PPGL patients and 76 age-, sex-matched healthy controls (30 males and 46 females). Areal bone mineral density (aBMD) was measured by dual-energy X-ray absorptiometry (DXA) simultaneously.

RESULTS

PPGL patients had a higher level of β-CTX. HR-pQCT assessment revealed that PPGL patients had notably thinner and more sparse trabecular bone (decreased trabecular number and thickness with increased trabecular separation), significantly decreased volume BMD (vBMD), and bone strength at both the radius and tibia compared with healthy controls. The deterioration of Tt.vBMD, Tb.Sp, and Tb.1/N.SD was more pronounced in postmenopausal patients compared with the premenopausal subjects. Moreover, subjects in the highest 24hUNE quartile (Q4) showed markedly lower Tb.N and higher Tb.Sp and Tb.1/N.SD at the tibia than those in the lowest quartile (Q1). Age-related bone loss was also exacerbated in PPGL patients to a certain extent.

CONCLUSIONS

PPGL patients had significantly deteriorated bone microarchitecture and strength, especially in the trabecular bone, with an increased bone resorption rate. Our findings provide clinical evidence that sympathetic overstimulation may serve as a secondary cause of osteoporosis, especially in subjects with increased sympathetic activity.

Encapsulation of Pure Water-Stable Perovskite Nanocrystals (PNCs) into Biological Environment-Stable PNCs for Cell Imaging

Recently emerging perovskite nanocrystals (PNCs) are very attractive fluorescence nanomaterials due to their very narrow emission peak, tunable wavelength, and extremely high quantum yield, but their chemosensing, biosensing and bioimaging applications suffer from the poor stability of ordinary PNCs in aqueous media, especially in biological matrices. Recently developed water-stable 2D CsPb2Br5-encapsulated 3D CsPbBr3 PNCs (i.e., CsPbBr3/CsPb2Br5 PNCs) show extremely stable light emission in pure water, but their fluorescence is seriously quenched in aqueous media containing biological molecules due to their chemical reactions. In this work, we used a facile method to encapsulate pure water-stable CsPbBr3/CsPb2Br5 PNCs in water with SiO2 and polyethylene glycol hexadecyl ether (Brij58) into a new kind of biological environment-stable PNCs (CsPbBr3/CsPb2Br5@SiO2-Brij58). The synthesis of the target PNCs can be accomplished in a fast, easy, and green way. The obtained CsPbBr3/CsPb2Br5@SiO2-Brij58 PNCs maintain strong fluorescence emission for a long time, all in pH 7.4 PBS, BSA, and minimum essential medium, exhibiting excellent biological environment stability. Moreover, the developed biological environment-stable PNCs show good biocompatibility and have been successfully used in cell imaging. Overall, the work provides an easy, low-cost, and efficient application of PNCs in bioimaging.

Photochromic Perovskite Nanocrystals for Ultraviolet Dosimetry

Excessive ultraviolet (UV) radiation has serious damage to human's health, therefore the development of visible, portable, and wearable sensor for monitoring UV radiation, especially the cumulative UV dosage, is highly desired but full of challenges. Herein, a wearable and flexible UV dosimeter based on photochromic perovskite nanocrystals (PNCs) is designed. The obtained CsPbCl3 PNCs dispersed in dibromomethane (PNCs-DBM) undergo continuous, vivid, and multiple (from very weak purple to blue, cyan, and finally strong green) color change in response to UV radiation. It is demonstrated that the UV-induced degradation of DBM and subsequent anion-exchange reaction between CsPbCl3 and Br- , play a crucial role in the color change of PNCs-DBM. The properties of continuous fluorescence color change and enhanced fluorescence intensity enable the construction of sensitive and visible UV dosimeter. Furthermore, by integrated photochromic PNCs with flexible bracelet or PDMS substrate, a wearable UV sensor or a multi-indicator array for the detection of solar UV dosage is developed. This work may advance the fundamental understanding about photochromic perovskite, and show promising application of perovskite nanomaterials in easily fabricated, low-cost, visualized, and wearable solar UV dosimeter.

[Establishment of a digital remote platform for respiratory support and intelligent early warning in intensive care units]

During the disease progression or treatment of critically ill patients with lung injury, the changes in respiratory mechanics are continuous and dynamic. Establishing a digital platform for respiratory support in the ICU, which enables the continuous recording, dynamic analysis, and real-time alerting of numerical and waveform data from mechanical ventilation, can help intensivists improve their understanding of "dynamic respiratory mechanics", improve respiratory therapy and patient outcomes, as well as reduce workload and increase work efficiency. The construction of a dedicated database for mechanical ventilation, based on ventilator waveforms provides essential data support for projects such as respiratory mechanics data algorithm models. This will facilitate the establishment of an auxiliary decision-making system, enable the realization of intelligent mechanical ventilation, and create a new era of dynamic respiratory mechanics.

Hydrochromic Perovskite System with Reversible Blue-Green Color for Advanced Anti-Counterfeiting

The intrinsic instability of halide perovskites toward to external stimulus, has created a competitive advantage for designing stimuli-responsive materials. However, the external environment tuning reversibly fluorescence emission of perovskite system is still limited. In this work, humidity is verified to act as a new option to modulate the emission properties of mixed-halide perovskite. The perovskite nanocrystals (PNCs) photoirradiated in dichloromethane are easily and stably redispersed in water, and emit bright fluorescence which is quite different from the original. Moreover, the perovskites confined on glass slide can reversibly switch their fluorescence between blue and green colors under moisture. It is demonstrated that the factors of different solubilities of CsCl and CsBr in water, the structural transformation of perovskites and the confine of glass matrix play key roles in the reversible transformation. Finally, the combination of hydrochromic CsPb(Brx Cly )3 and water-resistant CsPb(Brx Cly )3 -polymethyl methacrylate have been applied in advanced anti-counterfeiting, which greatly improves the information security. This work not only give an insight into the effects of humidity on fluorescence and structures of PNCs, but also offer a new class of hydrochromic PNCs materials based on reversible emission transformation for potential application in sensors, anti-counterfeiting and information encryption.

Anion Exchanges of Water-Stable Perovskite Nanocrystals in the Pure Water Phase and Applications in Detecting Halide Ions via a Smartphone-Based Sensing Platform

Recently, the newly emerging lead halide perovskite nanocrystals (PNCs) have been intensely researched in many fields, such as light-emitting diodes (LEDs), solar cells, lasers, and display devices. The extremely high fluorescence quantum yield (near 100%) of PNCs over classic fluorescent materials would enable good applications of PNCs in sensing. However, the study on PNCs for bio- and chemical sensing, especially for detecting targets that exist in aqueous medium, faces great challenges due to the well-known instability of PNCs in polar solvents, especially water. Although the encapsulation of polymers or inorganic materials can efficiently protect PNCs from decomposition in aqueous solution, the sensing based on the interaction between PNCs and targets is severely hindered by the compact protection coating at the surfaces of PNCs. In this work, novel water-dispersed PNCs (W-PNCs), i.e., CsPbBr₃@CsPb₂Br₅ PNCs, with strong fluorescence and excellent water stability were synthesized from OAm-capped CsPbBr₃ PNCs by a simple "oil-solid-water" phase transition. The W-PNCs without being encapsulated with compact polymers or inorganic materials can sensitively and stably sense targets in the pure water phase via direct chemical reactions. For the first time, ion exchanges between PNCs and halide ions and their effects on the fluorescence wavelength of PNCs were investigated in the pure water phase, on the basis of which a new, visualized, selective, and sensitive smartphone-based sensing platform for halide ions has been established by the integration of the conveniently prepared W-PNC nanoprobe and the portable mobile phone. It is envisioned that the uncoated but extremely water-stable and highly fluorescent W-PNCs have promising applications in chemical sensing, biosensing, and bioimaging of targets in aqueous medium.

Facile Synthesis of Oxidized Boron Nanosheets for Chemo- and Biosensing

As recently emerging nanomaterials, boron nanosheets (BNSs) have attracted more and more attention in various fields such as supercapacitors, photodetectors, bioimaging, and electrocatalysis due to their advantages of good biological compatibility, environmental friendliness, and good electro-optical properties. However, the study and application of BNSs in chemical and biological sensing are still in the infant stage, mainly due to the requirement of complicated, high-cost, and time-consuming preparation strategies. In this work, a new class of BNSs, namely oxidized-BNSs (i.e., ox-BNSs), were easily and rapidly synthesized by chemically treating boron powder with diluted HNO₃ in a very short time (less than 15 min). The composition, morphology, optical property, and peroxidase mimetic activity of obtained ox-BNSs were investigated in detail. The prepared ox-BNSs were several-layered nanosheets with abundant oxygen-containing groups, emitted blue fluorescence, and possessed good intrinsic peroxidase mimetic activity, based on which a sensitive and selective colorimetric sensor was developed for detection of H₂O₂ and glucose. The new easy preparation strategy and good sensing performances of the prepared ox-BNSs would greatly stimulate the study and application of BNSs in chemo- and biosensing.

[A case report of autosomal recessive bestrophinopathy]

The patient is a 40-year-old male who presented to the ophthalmology clinic due to easy visual fatigue for the past 3 months. Two months ago, the patient was misdiagnosed with "bilateral posterior uveitis", but the diagnosis was ruled out after ineffective treatment with corticosteroids. During the current visit, fundus examination revealed yellow-white material exudation below the macular center in both eyes. Considering the results of the ophthalmic examination and the genetic testing of the patient and his son, the patient was diagnosed with autosomal recessive bestrophinopathy.

[The 501st case: elevated blood glucose, chronic pancreatitis, and post- pancreatoduodenectomy malnutrition]

A 50-year-old man with a 15-year history of elevated blood glucose and an approximately 2-year history of diarrhea was admitted to the Peking Union Medical College Hospital. The initial diagnosis was type 2 diabetes. After repeated pancreatitis and pancreatoduodenectomy, severe pancreatic endocrine and exocrine dysfunction including alternating high and low blood glucose and fat diarrhea occurred. Tests for type 1 diabetes-related antibodies were all negative, C-peptide levels were substantially reduced, fat-soluble vitamin levels were reduced, and there was no obvious insulin resistance. Therefore, a diagnosis of pancreatic diabetes was clear. The patient was given small doses of insulin and supplementary pancreatin and micronutrients. Diarrhea was relieved and blood glucose was controlled. The purpose of this article is to raise clinicians' awareness of the possibility of pancreatic diabetes after pancreatitis or pancreatic surgery. Timely intervention and monitoring may reduce the occurrence of complications.

High prevalence of vertebral deformity in tumor-induced osteomalacia associated with impaired bone microstructure

PURPOSE

Patients with tumor-induced osteomalacia (TIO) often suffer from irreversible height loss due to vertebral deformity. However, the prevalence of vertebral deformity in TIO patients varies among limited studies. In addition, the distribution and type of vertebral deformity, as well as its risk factors, remain unknown. This study aimed to identify the prevalence, distribution, type and risk factors for vertebral deformity in a large cohort of TIO patients.

METHODS

A total of 164 TIO patients were enrolled in this retrospective study. Deformity in vertebrae T4-L4 by lateral thoracolumbar spine radiographs was evaluated according to the semiquantitative method of Genant. Bone microstructure was evaluated by trabecular bone score (TBS) and high-resolution peripheral QCT (HR-pQCT).

RESULTS

Ninety-nine (99/164, 60.4%) patients had 517 deformed vertebrae with a bimodal pattern of distribution (T7-9 and T11-L1), and biconcave deformity was the most common type (267/517, 51.6%). Compared with patients without vertebral deformity, those with vertebral deformity had a higher male/female ratio, longer disease duration, more height loss, lower serum phosphate, higher bone turnover markers, lower TBS, lower areal bone mineral density (aBMD), lower peripheral volumetric BMD (vBMD) and worse microstructure. Lower trabecular vBMD and worse trabecular microstructure in the peripheral bone and lower spine TBS were associated with an increased risk of vertebral deformity independently of aBMD. After adjusting for the number of deformed vertebrae, we found little difference in clinical indexes among the patients with different types of vertebral deformity. However, we found significant correlations of clinical indexes with the number of deformed vertebrae and the spinal deformity index.

CONCLUSION

We reported a high prevalence of vertebral deformity in the largest cohort of TIO patients and described the vertebral deformity in detail for the first time. Risk factors for vertebral deformity included male sex, long disease duration, height loss, abnormal biochemical indexes and bone impairment. Clinical manifestation, biochemical indexes and bone impairment were correlated with the number of deformed vertebrae and degree of deformity, but not the type of deformity.

Highly Electrochemiluminescent Cs4PbBr6@CsPbBr3 Perovskite Nanoacanthospheres and Their Application for Sensing Bisphenol A

Perovskite quantum dots (PQDs) as recently emerging electrochemiluminescence (ECL) luminophores have been paid much attention due to their good ECL activity, narrow ECL spectra, and easy preparation. However, the PQDs used for ECL sensing were mainly inherited from those PQDs prepared as strong fluorescence (FL) luminophores, which would limit the finding of highly ECL PQDs for sensing due to the very different mechanisms in generating excited-state luminophores between ECL and FL. In order to obtain highly electrochemiluminescent PQDs, for the first time we proposed to synthesize PQDs for ECL sensing rather than for FL-based analysis by optimizing the synthesis conditions. It was revealed that the volume of the precursor solution, the concentrations of CsBr and PbBr₂, the amount of capping reagents, and the synthesis reaction temperature all significantly affect the ECL activity of PQDs. On the basis of the optimization of the synthesis conditions, we obtained a new type of PQDs with high ECL activity. The new PQDs were characterized by several technologies, such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray spectrum, to be the hybrids of 3D PQDs (CsPbBr₃) and 0D PQDs (Cs₄PbBr₆) with unique morphologies, i.e., Cs₄PbBr₆@CsPbBr₃ PQD nanoacanthospheres (PNAs), in which Cs₄PbBr₆ was as the core and CsPbBr₃ served as the shell. The obtained Cs₄PbBr₆@CsPbBr₃ PNAs had much higher (>4 times) ECL activity than the prevailing 3D (CsPbBr₃) PQDs. Finally, the novel Cs₄PbBr₆@CsPbBr₃ PNAs have been applied for the ECL sensing of bisphenol A (BPA), showing a promising application of the highly electrochemiluminescent PQDs in analytical chemistry.

Alcohol-Stable Perovskite Nanocrystals and Their In Situ Capsulation with Polystyrene

In recent years, lead halide perovskite nanocrystals (PNCs) have presented potential scalable applications in all fields due to their outstanding properties. However, most commonly used PNCs capped with oleic acid (OA) and oleylamine (OAm) suffer from bad stability in polar solutions and thus require various surface protections with organic or inorganic materials. Encapsulation with highly hydrophobic polystyrene (PS) is one of the most efficient ways to protect PNCs; however, the presently used swelling-shrinking strategy faces several challenges, such as weak interaction between PS chains and the surface ligands in nonpolar media causing a low encapsulation efficiency, and serious aggregation of PS particles during the shrinkage process leading to very different particle sizes. Herein, alcohol-stable polyacrylic acid-capped CsPbBr3 PNCs (i.e., PAA-PNCs) are first synthesized and then in situ encapsulated with PS shells by polymerizing styrene monomer on the PNC surfaces in a polar organic solvent (e.g., ethanol). The in situ PS-encapsulated PAA-PNCs (i.e., PAA-PNCs@iPS) exhibit outstanding monodispersity, remarkable water, heat, and UV stability, high fluorescence activity, and color purity. The unique synthesis strategy and good performances of PAA-PNCs@iPS will boost the applications of PNCs in LEDs, biological imaging, and chemosensing.

Gold nanoparticles-oxidized multi-walled carbon nanotubes as electrochemiluminescence immunosensors

Oxidized multi-walled carbon nanotube/nano-gold (AuNP-ox-MWCNT) composites with strong electrochemiluminescence (ECL) activity were applied to construct a new ECL immunosensor for the detection of carcinoembryonic antigen (CEA). The immunosensor showed a linear response range of 10-100 ng mL^-1 and detection limit of 0.76 ng mL^-1 (at a signal-to-noise ratio of 3). The as-developed immunosensor exhibited several advantages, including being simple to fabricate and being label free. The results indicated that ox-MWCNTs as a luminescent material have great application potential in analysis.

The efficacy and safety of different doses of calcitriol combined with neutral phosphate in X-linked hypophosphatemia: a prospective study

The present study was the first prospective cohort evaluated the efficacy and safety of different doses of calcitriol in XLH children. The results suggested that a dose of 40 ng/kg/day calcitriol, compared with 20 ng/kg/day, was more effective in relieving the rickets, with similar safety outcomes. Further investigations were expected to set more dose groups.

INTRODUCTION

Dose recommended for calcitriol in X-linked hypophosphatemia (XLH) varies in different studies. Therefore, we aimed to compare the efficacy as well as the safety of 20 ng/kg/d and 40 ng/kg/d calcitriol in Chinese XLH pediatrics population.

METHODS

A 2-year, randomized, open-label, prospective study recruited 68 XLH children, which were randomized to receive either 40 ng/kg/day or 20 ng/kg/day calcitriol. Efficacy endpoints were the total Thacher ricket severity score (RSS) change from baseline to month 12 and 24, the difference in serum TALP level, fasting serum phosphate level, body height Z-score, and frequency of dental abscess. Safety assessments were done using renal ultrasound nephrocalcinosis grades (0-4), fasting serum and 24 h urine calcium level, and the occurrence of hyperparathyroidism.

RESULTS

The decrease in the total RSS from baseline was more significant in the high-dose group at 12 (difference 0.87, p = 0.049) and 24 month (difference 1.23, p = 0.011). The serum TALP level was significantly lower in the high-dose group at 6 months. Pi level, height Z-score change, frequency of dental abscess and ratio of de novo nephrocalcinosis were comparable. A lower incidence of secondary hyperparathyroidism was seen in the high-dose group (p < 0.0001).

CONCLUSION

For the first time in this prospective cohort, 40 ng/kg/d calcitriol was shown to be the more effective therapy in XLH children than the 20 ng/kg/d. Moreover, 40 ng/kg/d calcitriol was not associated with increasing adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT 03,820,518.

Treatment-related adverse events as predictive biomarkers of efficacy in patients with advanced neuroendocrine tumors treated with surufatinib: results from two phase III studies

Background

No validated biomarkers currently exist for predicting the efficacy outcomes in patients with neuroendocrine tumors (NETs) treated with antiangiogenic therapy. We aimed to evaluate the association between treatment-related adverse events (TRAEs) and efficacy outcomes of surufatinib in patients with advanced NET.

Patients and methods

We included patients with NET treated with surufatinib in two multicenter, randomized, double-blind, placebo-controlled, phase III trials (SANET-p and SANET-ep) in this study. The main exposure was the presence of any of the TRAEs including hypertension, proteinuria, and hemorrhage in the first 4 weeks of surufatinib treatment. The primary outcome of the study was investigator-assessed progression-free survival (PFS). PFS outcomes were estimated using the Kaplan–Meier method with the log-rank test. Hazard ratios (HRs) were calculated by using univariable and multivariable Cox proportional hazard regression models. Blinded independent image review committee (BIIRC) assessments and 4-week landmark analysis were also performed as supportive evaluations.

Results

During the study period, a total of 242 patients treated with surufatinib were included in the analysis, and 164 (68%) patients had at least one of hypertension, proteinuria, and hemorrhage in the first 4 weeks of treatment. The presence of TRAEs in the first 4 weeks was associated with prolonged median PFS [11.1 versus 9.2 months; HR 0.67, 95% confidence interval (CI) 0.47-0.97; P = 0.036]. In multivariable Cox regression analysis, the presence of TRAEs was also significantly associated with longer PFS (HR 0.65, 95% CI 0.44-0.97; P = 0.035). Similar results were obtained in the BIIRC assessments and 4-week landmark analysis.

Conclusions

Treatment-related hypertension, proteinuria, and hemorrhage could be potential biomarkers to predict antitumor efficacy of surufatinib in patients with advanced NET. Future prospective studies are needed to validate the findings.

Trial registration

ClinicalTrials.govNCT02589821; https://clinicaltrials.gov/ct2/show/NCT02589821 and ClinicalTrials.gov NCT02588170; https://clinicaltrials.gov/ct2/show/NCT02588170

•

Treatment-related hypertension, proteinuria, or hemorrhage is associated with longer survival in NETs.

•

The association is confirmed by the BIIRC assessments and 4-week landmark analysis.

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TRAEs can be biomarkers to predict antitumor efficacy in patients with NET.

[Treatment of 11 cases of juvenile idiopathic arthritis by intra-articular injection of adalimumab]

Objective: To evaluate the efficacy and safety of intra-articular injection of adalimumab (ADA) in the treatment of refractory oligoarticular juvenile idiopathic arthritis (JIA). Methods: This was a retrospective study. Clinical data on age, gender, and symptoms of joint swelling and pain were collected from 11 children with refractory oligoarticular JIA involving only knee joints admitted to Department of Rheumatism and Immunology of Children's Hospital, Capital Institute of Pediatrics from November 2019 to October 2020. The physician and parent-child evaluation of disease activity, the number of active joints, and the level of erythrocyte sedimentation rate (ESR) at different treatment time points were analyzed at every 4-week observation point after drug administration, and the non-parametric Kruskal-Wallis test was used to compare the differences in clinical evaluation indicators and changes in laboratory tests at different treatment times. The follow-up period was 6 months. Results: Among the 11 children, 5 were boys and 6 were girls. The age was 3.0 (2.8) years. All 11 children had symptoms of joint swelling and pain as well as limitation of movement. After 3 intra-articular injections of ADA, the joint symptoms of 11 children were better than before treatment; the joint symptoms of 7 children disappeared completely, and no recurrence occurred during the 6-month follow-up period. At different treatment times, physician and parent-child evaluation of disease activity, a gradual decrease in the number of active joints in the children, ESR, and juvenile arthritis disease activity score with 27 joints were all statistically significant (χ²=53.99, 59.37, 32.87, 40.07, 54.00, all P<0.001).No significant adverse drug reactions were observed in any of the 11 children during treatment and follow-up. Conclusion: Intra-articular injection of ADA in the treatment of refractory oligoarticular JIA has a significant effect in controlling joint symptoms and is relatively safe.

Phototriggered color modulation of perovskite nanoparticles for high density optical data storage

The perovskite nanocrystals-dichloromethane (PNCs-DCM) with tunable fluorescent color under UV light are a new kind of photoresponsive luminescent materials (PLMs), which are qualified to apply in optical data storage.

A visualized ratiometric fluorescence sensing system for copper ions based on gold nanoclusters/perovskite quantum dot@SiO2 nanocomposites

Excessive copper ions (Cu²⁺) cause serious environmental pollution and even endanger the health of organisms. Fluorescence chemosensing materials are widely used in the detection of metal ions due to their simple operation and high sensitivity. In this study, SiO₂-encapsulated single perovskite quantum dot (PQD@SiO₂) core-shell nanostructures which show strong, stable, and green fluorescence are synthesized and composited with gold nanoclusters (AuNCs) which show Cu²⁺-sensitive and red light-emitting fluorescence to obtain a visualized ratiometric fluorescence sensor (AuNCs/PQD@SiO₂) for the detection of Cu²⁺. In the visualized detection of Cu²⁺, the green fluorescence emitted from the ion-insensitive PQD@SiO₂ component is used as a reference signal and the red fluorescence emitted by ion-sensitive AuNC component is adopted as a sensing signal. In the presence of Cu²⁺, the red fluorescence is quenched whereas the green fluorescence remains stable, which results in a visualized fluorescence color change from orange-red to yellow and finally to green with increasing Cu²⁺ concentration. The significant change in the fluorescence color of AuNCs/PQD@SiO₂ in response to Cu²⁺ enables a rapid, sensitive, and visualized detection of Cu²⁺. Further accurate and sensitive ratiometric fluorescence analysis of Cu²⁺ can be accomplished by measuring the ratio of fluorescence intensities at 643 and 520 nm (I₆₄₃/I₅₂₀) at a certain Cu²⁺ level. The developed AuNCs/PQD@SiO₂-based sensor has been validated by its satisfactory application in the detection of Cu²⁺ in human serum and environmental water samples.

Colorimetric immunosensor based on glassy carbon microspheres test strips for the detection of prostate-specific antigen

Micro-sized glassy carbon microspheres (GCMs, typically 3 μm in diameter) instead of nano-sized gold nanoparticles (AuNPs, typically 20 nm in diameter) were for the first time used as signal markers for the quantitative detection of antigen such as prostate-specific antigen (PSA). After being treated with concentrated HNO₃, GCMs bear carboxyl groups at their surfaces, which enables antibodies to be conjugated with GCMs to yield new type of micro-sized material-based colorimetric probes used for immunochromatographic test strips (ICTSs). The captured black GCMs (with strong and wide-band light absorption) on the T-line of ICTS were used both for qualitative and quantitative determination of PSA. In the case of quantitative determination, a lab-assembled optical strip reader system was used to measure the reflected LED light intensity at 550 nm. The sensing performances of the developed GCM-based ICTSs, such as sensitivity, selectivity, reproducibility, stability, and applicability, were investigated in detail. The developed GCM-based ICTSs can have much higher (3 times) detection sensitivity than AuNP-based ICTSs, showing promising applications in sensitive immunoassay.

Differential effects of aquatic anaesthetics on the pharmacokinetics of antibiotics: Examples using florfenicol in Nile tilapia (Oreochromis niloticus)

Anaesthetics are commonly applied in pharmacokinetic (PK) studies to assure smooth handling of experimental procedures or to promote animal welfare. However, the influence of anaesthetics on the PK of co-administered drug is generally unknown but assumes ignorable. The goal of the study was to investigate the effect of tricaine methanesulfonate (MS-222), 2-phenoxyethanol (2-PE) and eugenol (EUG) on the PK of florfenicol (FF) in Nile tilapia. Twenty-eight fish were repeatedly exposed to 90 ppm EUG, 300 ppm MS-222 or 900 ppm 2-PE before FF oral administration (15 mg/kg) and each successive blood sampling. The serum concentration-time profiles were analysed by a 2-compartmental model, and the generated parameters in the control (without anaesthetic) and anaesthetic groups were statistically compared. The results demonstrated that the serum concentrations of each anaesthetic were similar at every FF sampling times (70 μg/ml for MS-222; 277 μg/ml for 2-PE; and 61 μg/ml for EUG). In comparison with the control group, the repeated use of MS-222 did not result in a statistical difference in most of the PK parameters. In contrast, the elimination half-lives of the 2-PE and EUG groups were significantly longer whereas the absorption and distribution half-lives of the 2-PE group were significantly shorter than the control, resulting in altered optimal dosages in the simulation modelling. Whether or not the numbers and extent of PK parameters change mitigate subsequent estimations of other PK-derived secondary values such as dosing regimen and withdrawal time remains to be elucidated, but the auxiliary use of anaesthetics in PK studies should not assume uninfluential.

A simple enzyme-catalyzed reaction induced "switch" type fluorescence biosensor based on carbon nitride nanosheets for the assay of alkaline phosphatase activity

An enzyme-catalyzed fluorescence "switch" type sensor was constructed for the determination of alkaline phosphatase (ALP) activity by combining the fluorescence quenching effect of Ag+ on ultrathin g-C3N4 nanosheets (CNNSs) with the simple redox reaction of AA and Ag+. Briefly, Ag+ exhibits a significant quenching effect on the fluorescence of CNNSs. Thus the fluorescence signal of the CNNS-Ag+ system is extremely weak even in the presence of l-ascorbic acid-2-phosphate (AAP) ("off" state). When ALP coexists in the system, the enzyme can specifically catalyze the hydrolysis of AAP to form ascorbic acid (AA), which reduces Ag+ to Ag0. In this case, the fluorescence signal of the system is recovered ("on" state). Based on this principle, a signal-enhanced CNNS fluorescence sensor was developed to determine the activity of alkaline phosphatase. The experimental results show that the detection range of alkaline phosphatase is 0.5-20 U L-1, and the detection limit is 0.05 U L-1 (S/N = 3). Meanwhile, this method was used to assay ALP in serum samples.

[Technology specification of bedside hypertonic saline-contrast electrical impedance tomography of lung perfusion and clinical application]

Bedside hypertonic saline-contrast electrical impedance tomography (EIT) method for lung perfusion evaluation has several advantages of bedside, simple, noninvasive and radiation-free. For a long time, EIT perfusion image of hypertonic saline was mostly limited to animal experiments, and related clinical research is in the ascendant. This technical specification for clinical application is reached based on our previous researches, review of literatures in this field. The purpose of this technical specification is to facilitate the unified and standardized use of hypertonic saline-contrast EIT technology for regional lung perfusion, to evaluate the safety and quality control of the technology, and to unify the results.

Iron deficiency plays essential roles in the trigger, treatment, and prognosis of autosomal dominant hypophosphatemic rickets

By analyzing iron status of 14 ADHR patients, we found that iron deficiency was an important trigger of ADHR. Correcting iron deficiency significantly improved patients' symptoms. Meanwhile, patients' serum phosphate showed positive correlations with iron metabolism parameters and hemoglobin-related parameters, suggesting the necessity of monitoring and correcting the iron status in ADHR.

INTRODUCTION

Autosomal dominant hypophosphatemic rickets (ADHR) is unique for its incomplete penetrance, variety of disease onsets, and waxing and waning phenotypes. Iron deficiency is a trigger of ADHR. This study aimed to clarify the role of iron deficiency in ADHR.

METHODS

Data of clinical manifestations and laboratory examinations were collected from patients among eight kindreds with ADHR. Multiple regression and Pearson's correlation tests were performed to test the relationships of serum phosphate levels and other laboratory variables during the patients' follow-ups.

RESULTS

Among 23 ADHR patients with fibroblast growth factor 23 (FGF23) mutations, 14 patients presented with obvious symptoms. Ten patients had iron deficiency at the onset of ADHR, coinciding with menarche, menorrhagia, pregnancy, and chronic gastrointestinal bleeding. Two patients who did not have their iron status tested presented with symptoms after abortion and pregnancy in one patient each, which suggested that they also had iron deficiency at onset. Patients were treated with ferrous succinate tablets, vitamin C, and neutral phosphate and calcitriol. With correction of the iron status, the patients' symptoms showed notable improvement, with increased serum phosphate levels. Two patients' FGF23 levels also declined to the normal range. There were strong correlations between serum phosphate and serum iron levels (r = 0.7689, p < 0.0001), serum ferritin levels (r = 0.5312, p = 0.002), iron saturation (r = 0.7907, p < 0.0001), and transferrin saturation (r = 0.7875, p < 0.001). We also examined the relationships between serum phosphate levels and hemoglobin-related indices, which were significant (hemoglobin: r = 0.71, p < 0.0001; MCV: r = 0.7589, p < 0.0001; MCH: r = 0.8218, p < 0.0001; and MCHC: r = 0.7751, p < 0.0001). Longitudinal data of six patients' follow-up also showed synchronous changes in serum phosphate with serum iron levels.

CONCLUSIONS

Iron deficiency plays an important role in triggering ADHR. Monitoring and correcting the iron status are helpful for diagnosing and treating ADHR. Iron metabolism parameters and hemoglobin-related parameters are positively correlated with serum phosphate levels in patients with ADHR and iron deficiency, and these might serve as good indicators of prognosis of ADHR.

Simultaneous determination of six glycosidic aroma precursors in pomelo by ultra-high performance liquid chromatography-tandem mass spectrometry

An ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was established and validated for the simultaneous determination of six glycosidic aroma precursors in pomelo, including geraniol β-glucoside, geraniol β-primeveroside, linalool β-primeveroside, benzyl β-primeveroside, 2-phenylethyl β-primeveroside and nerolidol β-primeveroside. The results showed that the proposed method has the advantages of rapidity, high sensitivity, and good accuracy. Six glycosidic aroma precursors were effectively separated in a short run time (13 min), and the limit of detection, limit of quantification, recovery, and repeatability of analytes were 0.321-4.47 ng mL^-1, 1.07-14.9 ng mL^-1, 94.4-109.1%, and 5.2-14.5%, respectively. The developed method was applied to analyze the contents of glycosidic aroma precursors in different organs of pomelo plant, including leaves, flowers and fruits. The analytical result showed that glycosidic aroma precursor contents in plant leaves, flowers and fruits were in the range of 0-5964.9 μg kg^-1, and more glycosidic aroma precursors were found in flowers than in leaves or fruits. It is envisioned that the proposed UPLC-MS/MS method have promising application in qualifying and quantifying these six glycosidic aroma precursors in pomelo.

Label-Free and Ultrasensitive Electrochemiluminescent Immunosensor Based on Novel Luminophores of Ce2Sn2O7 Nanocubes

In this research article, a novel and simple label-free electrochemiluminescence (ECL) immunosensor using cerium stannite (Ce₂Sn₂O₇) nanocubes as brand-new ECL emitters has been suggested for the first time. Ce₂Sn₂O₇ nanocubes prepared by a simple hydrothermal method displayed bright ECL emission, promising biocompatibility, low noxiousness, and perfect stability. On comparison of ECL and photoluminescence (PL) spectra, a surface-state mechanism was proposed to be involved in the ECL emission. After aminofunctionalization with 3-aminopropyltriethoxysilane (APTES), Ce₂Sn₂O₇ could be decorated with gold nanoparticles through Au-NH₂ covalent linkage, which yielded Au@Ce₂Sn₂O₇ nanocomposites and further enhanced the ECL emission. To confirm the proposed immunosensor feasibility, carcinoembryonic antigen (CEA) was employed as an exemplary analyte. Based on the abovementioned points, our fabricated immunosensor improved the ECL performance to CEA concentrations in a linear range of 0.001-70 ng/mL with a low limit of detection of 0.53 pg/mL (S/N = 3). With outstanding stability, reproducibility, and specificity, this method is expected to be an innovative one for sensitive analyses of CEA and other biomarkers in real samples.

[Infliximab in infantile Takayasu arteritis: a case report and literature review]

Objective: To analyze the clinical characteristics of infantile Takayasu arteritis and the efficacy of infliximab (IFX). Methods: Clinical manifestations, laboratory investigations and infliximab intervention of a case with infantile Takayasu arteritis, who was admitted to Department of Rheumatism and Immunology, Children's Hospital, Capital Institute of Pediatrics in January 2018, were reviewed and analyzed. The related literature published from the beginning to March 2020 were retrieved from CNKI, Wanfang, SinoMed and PubMed with the keywords of"Takayasu arteritis","Infant" in both Chinese and English. Results: This case was a 70-day-old boy admitted due to recurrent fever for 20 days. On admission, his blood pressure were 104/90, 95/59, 125/80, and 152/125 mmHg (1 mmHg=0.133 kPa) in the right arm, left arm, right leg, and left leg, respectively. The complete blood cell count showed leukocytosis (22.6×10⁹/L), thrombocytosis (858×10⁹/L) and mild anemia (80 g/L). He also had elevated erythrocyte sedimentation rate (119 mm/1h), serum ferritin (598 μg/L) and C-reactive protein (112 mg/L). Computed tomographic angiography (CTA) showed narrowing of the thoracic and abdominal aorta, with thickening and heterogenous enhancement of the vessel wall. Coronary artery ultrasound detected dilatation and wall thickening of the bilateral coronary arteries, and uneven dilatation of the middle segment of the right coronary artery, showing bead-like change. Vessel wall thickening was also found in the other main arteries, including both femoral arteries, axillary arteries, carotid arteries, and subclavian arteries, and both superficial femoral arteries were slightly narrowed in the distal segments. The diagnosis of TA was confirmed, and the boy was treated with infliximab monotherapy (5 mg/(kg·every time), a total of 13 times). Then his body temperature and all inflammatory markers were normalized, and the vascular pathology was resolved according to the radiography. No side effects such as allergy or infection were noted during the treatment. During the 2 years and 6 months of follow-up, the boy maintained normal growth and development. Literature review found 8 related articles, and one of them was in Chinese but had limited information. In the other 7 papers, a total of 7 infants with TA were reported. The most common symptom was fever (5 cases), and inflammatory markers usually elevated, and the most common affected artery was abdominal aorta (6 cases). Most cases were treated with glucocorticoid. Conclusions: TA is a rare disease in infants, usually presents with fever and increased inflammatory markers. At the early stage, infliximab monotherapy could effectively control the symptoms and ensure normal growth and development.

Electrochemiluminescence from the Graphene- and Fullerene-Like Nanostructures of Glassy Carbon Microspheres and Its Application in Immunoassay

Glassy carbon (GC) as a well-known electrode material has recently been proposed to consist of fullerene-like nanostructures. In order to verify the nanostructures in GC, find more physiochemical properties of GC, and develop sensors based on GC-related carbon nanomaterials, we investigated the morphologies and surface states of GC microspheres (GCMs) and their HNO₃-oxidized products (ox-GCMs) with scanning electron microscopy (SEM), electrochemiluminescence (ECL), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron-paramagnetic resonance (EPR) spectroscopy. Our research results reveal that ox-GCMs rather than raw GCMs have abundant surface states, including many carboxyl groups (-COOH), surface defects (or carbon edges), and C-related dandling bonds. The surface states with a band gap of 2.14 eV endow ox-GCMs with strong cathodic ECL activity in the presence of peroxydisulfate (S₂O₈^2-). The ECL behaviors and maximum emission wavelength (580 nm) of ox-GCMs are very similar to those of small-sized graphene quantum dots and fullerene-like nanosheets, verifying that GCMs are essentially 3-D nanomaterials consisting of graphene or fullerene-like carbon nanostructures. It is for the first time that a microsized carbon material was reported to have good ECL activity in aqueous media. Possible mechanisms for surface state formation and ECL reactions are proposed for ox-GCMs, and a promising application of ox-GCMs in ECL immunosensing has been demonstrated by determining prostate specific antigen (PSA) as a model cancer biomarker.

Research on protective mechanism of ibuprofen in myocardial ischemia-reperfusion injury in rats through the PI3K/Akt/mTOR signaling pathway

OBJECTIVE

To study the protective mechanism of ibuprofen (Ib) in myocardial ischemia-reperfusion (I/R) injury in rats, and to analyze its regulatory effect on the phosphatidylinositol 3-hydroxy kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway.

MATERIALS AND METHODS

The rat model of myocardial I/R injury was established via ligation of the left main coronary artery (LCA) for 30 min and then reperfusion for 120 min. A total of 36 Sprague-Dawley (SD) rats were randomly divided into sham group (S group, n=12), model group (I/R group, n=12) and Ib group (n=12). The levels of serum creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) in each group were detected. The rats were executed, the heart was isolated and the area of myocardial infarction was determined via 2,3,5-triphenyltetrazolium chloride (TTC) staining. The expression levels of vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1 (HIF-1) and apoptosis-related proteins in myocardial tissues in each group were detected via Western blotting. Moreover, the content of inflammatory factors in myocardial tissues in each group was detected using the enzyme-linked immunosorbent assay (ELISA) kit. The expression levels of related proteins in the PI3K/Akt/mTOR signaling pathway in myocardial tissues were further analyzed.

RESULTS

Compared with those in S group, the levels of CK-MB and LDH were significantly increased (p<0.01), the area of myocardial infarction was significantly increased (p<0.01), the VEGF, HIF-1 and Cleaved caspase-3 protein levels in myocardial tissues were increased (p<0.01), while Bcl-2/Bax declined (p<0.01), the content of interleukin-1 (IL-1), IL-6 and tumor necrosis factor-α (TNF-α) in myocardial tissues was increased (p<0.01), while the content of IL-10 declined (p<0.01), and the expression levels of PI3K, p-Akt and p-mTOR proteins in myocardial tissues were significantly decreased (p<0.01) in I/R group. Compared with those in I/R group, the levels of CK-MB and LDH were significantly decreased (p<0.01), the area of myocardial infarction was significantly decreased (p<0.01), the VEGF, HIF-1 and Cleaved caspase-3 protein levels in myocardial tissues were decreased (p<0.01), while Bcl-2/Bax was increased (p<0.01), the content of IL-1, IL-6 and TNF-α in myocardial tissues declined (p<0.01), while the content of IL-10 was significantly increased (p<0.01), and the expression levels of PI3K, p-Akt and p-mTOR proteins in myocardial tissues were significantly increased (p<0.01) in Ib group.

CONCLUSIONS

Ib can activate the PI3K/Akt/mTOR signaling pathway, reduce the release of inflammatory factors and apoptosis, and alleviate the myocardial I/R injury in myocardial cells in rats.

Endowing chloroplasts with artificial "cell walls" using metal-organic frameworks

Biological photosynthesis via chloroplasts (CHs) is widely recognized as the most appropriate and effective method to convert solar energy and simultaneously supply nutrition to maintain life on earth. It is of great significance to prepare CH-based biohybrids which not only can artificially simulate the photocatalytic functionality of CH-containing plants and bacteria, but also can be easily prepared, stored for a long period and conveniently utilized when needed. In this work, for the first time, CHs were encapsulated into metal-organic frameworks (MOFs), namely zeolitic imidazolate frameworks (ZIF-8), under very gentle reaction conditions, i.e. in aqueous solution and at room temperature. Without the negative effects of organic solvents and high temperature on synthesis, the obtained CH@ZIF-8 biohybrids not only have shells maintaining the porous structure of ZIF-8, but also well preserve the biological activity of CHs inside. The porous ZIF-8 coating on CHs acts as a "cell wall" to allow mass and energy exchange between CHs and the environment, and protect CHs from microbiological degradation, which significantly prolong the lifetime of CHs in vitro (raised from several days to >300 days). The CH@ZIF-8 biohybrids may have promising applications in "living" artificial leaves and even artificial trees capable of photosynthesis in the future.

Predicting the intervention threshold for initiating osteoporosis treatment among postmenopausal women in China: a cost-effectiveness analysis based on real-world data

This study built a micro-simulation Markov model to determine the treatment threshold of osteoporosis in postmenopausal women in Mainland China. Treatment with zoledronate is cost-effective when FRAX-based (Fracture risk assessment tool) fracture probability is over 7%.

INTRODUCTION

The purpose of this study is to estimate FRAX-based fracture probabilities in Mainland China using real-world data, at which intervention could be cost-effective.

METHODS

We developed a micro-simulation Markov model to capture osteoporosis states and relevant morbidities including hip fracture, vertebral fracture, and wrist fracture. Baseline characteristics including incidences of osteoporosis and distribution of risk factors were derived from the Peking Vertebral Fracture study, the largest prospective cohort study of postmenopausal women in Mainland China. We projected incidences of fractures and deaths by age groups under two treatment scenarios: 1) no treatment, and 2) zoledronate. We also projected total quality-adjusted life-years (QALY) and total costs including fracture management and osteoporosis drugs for cost-effectiveness analysis. Cost-effective intervention thresholds were calculated based on the Chinese FRAX model.

RESULTS

Treatment with zoledronate was cost-effective when the 10-year probability of major osteoporotic fracture based on FRAX was above 7%. The FRAX threshold increased by age from 51 to 65 years old, and decreased in elder age groups, ranging from 4% to 9%.

CONCLUSIONS

Using real-world data, our model indicated that widespread use of zoledronate was of both clinical and economic benefit among Chinese postmenopausal women. Using a FRAX-based intervention threshold of 7% with zoledronate should permit cost-effective access to therapy to patients and contribute to reducing the disease burden of osteoporosis in Mainland China.

[Gene mutation spectrum and clinical characteristics analysis of 178 patients with essential thrombocytosis]

目的

分析原发性血小板增多症（ET）患者基因突变谱及临床特征。

方法

对2009年2月1日至2018年11月1日收治的178例初诊ET患者进行回顾性分析。

结果

全部178例患者中，男89例，女89例，中位初诊年龄为49.5（3~86）岁。JAK2V617F基因突变频率为16.45%（1.67%~43.90%），CALR基因突变频率为40.00%（10.00%~49.15%），MPL基因突变频率为25.10%（25.00%~40.00%）。与CALR基因突变的患者相比，JAK2V617F基因突变患者具有较高的发病年龄（P=0.035）、初诊白细胞计数（P=0.040）、初诊血红蛋白浓度（P=0.001）和较低的初诊血小板计数（P=0.002）。47例（27.01%）患者诊断ET前发生血栓事件，3例（1.72%）诊断ET后发生血栓事件。多因素分析结果显示，年龄>60岁（P=0.013，OR=4.595，95%CI1.382~15.282）、心血管危险因素（P<0.001，OR=8.873，95%CI2.921~26.955）为血栓事件的危险因素，CALR基因突变（P=0.032，OR=0.126，95%CI0.019~0.838）为血栓事件的保护性因素。年龄>60岁（P=0.042，OR=4.045，95%CI1.053~15.534）是影响ET患者总生存时间的危险因素。年龄≤60岁、年龄>60岁患者的OS时间分别为（115.231±1.899）、（83.291±4.991）个月（χ²=6.406，P=0.011）。

结论

心血管危险因素、年龄>60岁为ET患者血栓事件的危险因素，CALR基因突变为血栓事件的保护性因素。年龄>60岁是影响ET患者总生存的危险因素。

Strong Electrochemiluminescence Emission from Oxidized Multiwalled Carbon Nanotubes

Carbon nanotubes (CNTs) as well-known nanomaterials are extensively studied and widely applied in various fields. Nitric acid (HNO₃ ) is often used to treat CNTs for purification purposes and preparing oxidized CNTs for various applications. However, too little attention is paid to investigating the effect of HNO₃ treatment on the optical properties of CNTs. In this work, it is observed for the first time that HNO₃ -oxidized multiwalled carbon nanotubes (ox-MWCNTs) have strong electrochemiluminescence (ECL) activity, which enables ox-MWCNTs to become new and good ECL carbon nanomaterials after carbon quantum dots (CQDs) and graphene quantum dots (GQDs). Various characterization technologies, such as transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, are used to reveal the relationship between ECL activity and surface states. The ECL behaviors of ox-MWCNTs are investigated in detail and a possible ECL mechanism is proposed. Finally, the new ECL nanomaterials of ox-MWCNTs are envisioned to have promising applications in sensitive ECL sensing and in the study of CNT-based catalysts.

A novel hybrid platform of g-C3N4 nanosheets /nucleic-acid-stabilized silver nanoclusters for sensing protein

The fabrication of nanomaterials-based sensing platform has attracted a great deal of interest due to their unique properties. Here, we report a novel hybrid platform of g-C₃N₄ nanosheets/DNA-stabilized Ag nanoclusters (CNNS/AgNCs) for sensing application. In this platform, the fluorescent AgNCs was synthesized using a pair of double-functional ssDNA sequence as a template, including the aptamer segment against thrombin and C-rich segment for AgNCs. Next, the interaction between the fluorescent Apt-AgNCs and CNNS was investigated. It is verified that DNA-stabilized AgNCs could absorb on the CNNS surface via the stronger π-π interaction to form the hybrid platform, whose fluorescence is quenched by CNNS through the photoelectron transfer effect (PET). When targets are introduced into the system, target/Apt-AgNCs complex will fall off from the CNNS surface, resulting in the fluorescence recovery. This hybrid platform can achieve the detection of biomolecule with high sensitivity and selectivity. Considering the fluorescence variability of DNA scaffold AgNCs, this hybrid platform is promising to extend to other target and even multi-target detection.

A multilayer-graphene nanosheet film deposited on a ceramic substrate without a catalyst for constructing an electrochemiluminescence imaging platform

Chemically and electrochemically stable conducting films are very desirable in the electrochemical industry and electrochemical sensing. In this work, ethanol was used as the carbon source to synthesize a multilayer-graphene nanosheet (MLGNS) film on ceramic substrates by a catalyst-free chemical vapor deposition (CVD) method at 900 °C and under ambient pressure. The developed CVD method is simple, economical and safe and avoids damage to the graphene nanosheet film during its transfer from the metal substrate to the non-metal substrate. The synthesized MLGNS film was well characterized by various techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The prepared MLGNS film has good chemical and electrochemical stability and satisfactory electrical conductivity thus can be used as a new type of electrode material. The MLGNS film on the ceramic substrate has been fabricated into an electrochemiluminescence (ECL) imaging platform to investigate the oxygen reduction reaction (ORR) and evaluate the activities of ORR catalysts, such as PtNPs. The established MLGNS film-based ECL imaging platform may have promising applications in the study of catalysts for fuel cells, high throughput immunoassay in the clinic, and fast screening of anti-cancer drugs.