Efficient chiral hydrogel template based on supramolecular self-assembly driven by chiral carbon dots for circularly polarized luminescence.

Since the chiral emission of excited states is observed on carbon dots (CDs), exploration towards the design and synthesis of chiral CDs nanomaterials with circularly polarized luminescence (CPL) properties has been at a brisk pace. In this regard, the "host and guest" co-assembly strategy based on the combination of CDs and chiral templates has been of unique interest recently for its convenient operation, multicolor tunable CPL, and wide application of prepared CDs-composited materials in optoelectronic devices and information encryption. However, the existing chiral templates that match perfectly with chiral CDs exhibiting optical activity both in ground and excited states are rather scarce. In this work, we synthesize the chiral CDs that could induce the spontaneous supramolecular self-assembly of N-(9-fluorenylmethox-ycarbonyl) (Fmoc)-protected glutamic acid to form chiral hydrogels with helical nanostructure. The co-assembled hydrogels show powerful chiral template function, which not only enable chiral CDs with a luminescence dissymmetry factor (glum) up to 10-2, but also have universal chiral transfer to inserted dye molecules, realizing full-color CPL and Förster resonance energy transfer (FRET) CPL as well as the distinction between left and right circularly polarized light. This CPL-active template based on chiral CDs enriches the design scenario of chiral functionalized nanomaterials.

Rb-Doped Perovskite Oxides: Surface Enrichment and Structural Reconstruction During the Oxygen Evolution Reaction.

Alkali-metal doped perovskite oxides have emerged as promising materials due to their unique properties and broad applications in various fields, including photovoltaics and catalysis. Understanding the complex interplay between alkali metal doping, structural modifications, and their impact on performance remains a crucial challenge. In this study, this challenge is addressed by investigating the synthesis and properties of Rb-doped perovskite oxides. These results reveal that the doping of Rb into perovskite oxides function as a structural modifier in the as-synthesized samples and during the oxygen evolution reaction (OER) as well. Electron microscopy and first-principles calculations confirm the enrichment of Rb on the surface of the as-synthesized sample. Further investigations into the electrocatalytic reaction revealed that the Rb-doped perovskite underwent drastic restructuring with Rb leaching and formation of strontium oxide.

Cohort profile of an early life observational cohort in China: Bone and MicroBiOme onset (BAMBOO) study.

PURPOSE: The Bone And MicroBiOme Onset (BAMBOO) study is an ongoing prospective observational cohort study conducted in Tianjin, China, aiming to determine age-appropriate trajectories for microbiome maturation and bone development and to identify the influence of dietary factors in the process. PARTICIPANTS: The recruitment started in September 2021 and was completed in February 2023. A total of 1380 subjects were recruited, 690 at birth (group 1) and 690 at 6 months of age (group 2). Groups 1 and 2 will be followed up for 12 months and 36 months, respectively. FINDINGS TO DATE: The age of the mothers was 31.1±3.7 (mean±SD), and the birth weight of infants was 3.3±0.5 kg with an incidence of caesarean section 50.4%. Food diary information of the first 100 subjects showed that 64 food items were introduced by 6 months. A pilot microbiome analysis revealed that at the species level, bacterial communities were composed of mostly Bacteroides dorei, Bacteroides vulgatus and Escherichia coli, which were consistent with that of previous reports. Feasibility assessments of breast milk vitamin D and human milk oligosaccharides were validated through certified reference measurements. The early data assessment showed a high reliability of the data generated from this study. FUTURE PLANS: Data collection will be completed in August 2025. Four stage-statistical analyses will be performed as the cohort reaches certain age thresholds before the final report. Analysis of BAMBOO data will be used to develop age-appropriate trajectories for microbiome maturation and bone development for children aged 0-3 years and investigate the contribution of dietary factors in the process. TRIAL REGISTRATION NUMBER: ChiCTR2100049972.

Joint association of overweight/obesity, high electronic screen time, and low physical activity time with early pubertal development in girls: a case-control study.

To examine the joint association of electronic screen time (EST), moderate-to-vigorous physical activity time (MVPA) and overweight/obesity with early pubertal development (EPD) in girls. A case-control study of 177 EPD girls and 354 girls with normal pubertal development was conducted between October 2019 and August 2022. Overweight/obesity was defined as body mass index ≥ 85th percentiles for age and sex. We found a non-significant increase of EPD risk among girls with high EST alone [OR: 2.75 (0.65-11.58)] or low MVPA alone [OR: 2.54 (0.74-8.69)], but a significant increase of EPD risk among girls with overweight/obesity alone [OR: 4.91 (1.01-23.92)], compared to girls without any of the three risk factors (low MVPA, high EST and overweight/obesity). Girls with any two of the three risk factors faced increased risk of EPD, and girls with all three risk factors faced the highest risk of EPD [OR and 95% CI: 26.10 (6.40-106.45)]. Being overweight/obesity might be more important than having low MVPA or high EST as a correlate of EPD compared to girls without any of the three risk factors, but the co-presence of low MVPA, high EST and overweight/obesity would largely increase the risk of EPD in girls.

Machine-Learning-Driven G-Quartet-Based Circularly Polarized Luminescence Materials.

Circularly polarized luminescence (CPL) materials have garnered significant interest due to their potential applications in chiral functional devices. Synthesizing CPL materials with a high dissymmetry factor (glum ) remains a significant challenge. Inspired by efficient machine learning (ML) applications in scientific research, this work demonstrates ML-based techniques for the first time to guide the synthesis of G-quartet-based CPL gels with high glum values and multiple chiral regulation strategies. Employing an "experiment-prediction-verification" approach, this work devises a ML classification and regression model for the solvothermal synthesis of G-quartet gels in deep eutectic solvents. This process illustrates the relationship between various synthesis parameters and the glum value. The decision tree algorithm demonstrates superior performance across six ML models, with model accuracy and determination coefficients amounting to 0.97 and 0.96, respectively. The screened CPL gels exhibiting a glum value up to 0.15 are obtained through combined ML guidance and experimental verification, among the highest ones reported till now for biomolecule-based CPL systems. These findings indicate that ML can streamline the rational design of chiral nanomaterials, thereby expediting their further development.

Truncated Electrochemical Aptasensor with Enhanced Antifouling Capability for Highly Sensitive Serotonin Detection.

Accurate determination of serotonin (ST) provides insight into neurological processes and enables applications in clinical diagnostics of brain diseases. Herein, we present an electrochemical aptasensor based on truncated DNA aptamers and a polyethylene glycol (PEG) molecule-functionalized sensing interface for highly sensitive and selective ST detection. The truncated aptamers have a small size and adopt a stable stem-loop configuration, which improves the accessibility of the aptamer for the analyte and enhances the sensitivity of the aptasensor. Upon target binding, these aptamers perform a conformational change, leading to a variation in the Faraday current of the redox tag, which was recorded by square wave voltammetry (SWV). Using PEG as blocking molecules minimizes nonspecific adsorption of other interfering molecules and thus endows an enhanced antifouling ability. The proposed electrochemical aptamer sensor showed a wide range of detection lasting from 0.1 nM to 1000 nM with a low limit of detection of 0.14 nM. Owing to the unique properties of aptamer receptors, the aptasensor also exhibits high selectivity and stability. Furthermore, with the reduced unspecific adsorption, assaying of ST in human serum and artificial cerebrospinal fluid (aCSF) showed excellent performance. The reported strategy of utilizing antifouling PEG describes a novel approach to building antifouling aptasensors and holds great potential for neurochemical investigations and clinical diagnosis.

Porphyrin Functionalized Carbon Quantum Dots for Enhanced Electrochemiluminescence and Sensitive Detection of Cu2.

Porphyrin (TMPyP) functionalized carbon quantum dots (CQDs-TMPyP), a novel and efficient carbon nanocomposite material, were developed as a novel luminescent material, which could be very useful for the sensitive detection of copper ions in the Cu2+ quenching luminescence of functionalized carbon quantum dots. Therefore, we constructed a sensitive "signal off" ECL biosensor for the detection of Cu2+. This sensor can sensitively respond to copper ions in the range of 10 nM to 10 µM, and the detection limit is 2.78 nM. At the same time, it has good selectivity and stability and a benign response in complex systems. With excellent properties, this proposed ECL biosensor provides an efficient and ultrasensitive method for Cu2+ detection.

Chiral Carbon Dots: Synthesis and Applications in Circularly Polarized Luminescence, Biosensing and Biology.

Chiral carbon dots (CDs) are a novel luminescent zero-dimensional carbon-based nanomaterial with chirality. They not only have the advantages of good biocompatibility, multi-color-emission, easy functionalization, but also exhibits highly symmetrical chiral optical characteristics, which broadens their applicability to enantioselectivity of some chiral amino acids like cysteine and lysine, asymmetric catalysis as well as biomedicine in gene expression and antibiosis. In addition, the exploration of the excited state chirality of CDs has developed its excellent circularly polarized luminescence (CPL) properties, opening up a new application scenario like recognition of chiral light sources and anti-counterfeit printing with information encryption. This review mainly focuses on the mature synthesis approaches of chiral CDs, including chiral ligand method and supramolecular self-assembly method, then we consider emerging applications of chiral CDs in CPL, biosensing and biological effect. Finally, we concluded with a perspective on the potential challenges and future opportunities of such fascinating chiral CDs.

New Horizons for MXenes in Biosensing Applications.

Over the last few decades, biosensors have made significant advances in detecting non-invasive biomarkers of disease-related body fluid substances with high sensitivity, high accuracy, low cost and ease in operation. Among various two-dimensional (2D) materials, MXenes have attracted widespread interest due to their unique surface properties, as well as mechanical, optical, electrical and biocompatible properties, and have been applied in various fields, particularly in the preparation of biosensors, which play a critical role. Here, we systematically introduce the application of MXenes in electrochemical, optical and other bioanalytical methods in recent years. Finally, we summarise and discuss problems in the field of biosensing and possible future directions of MXenes. We hope to provide an outlook on MXenes applications in biosensing and to stimulate broader interests and research in MXenes across different disciplines.

Near-infrared phosphorescent carbon dots for sonodynamic precision tumor therapy.

Theranostic sonosensitizers with combined sonodynamic and near infrared (NIR) imaging modes are required for imaging guided sonodynamic therapy (SDT). It is challenging, however, to realize a single material that is simultaneously endowed with both NIR emitting and sonodynamic activities. Herein, we report the design of a class of NIR-emitting sonosensitizers from a NIR phosphorescent carbon dot (CD) material with a narrow bandgap (1.62 eV) and long-lived excited triplet states (11.4 µs), two of which can enhance SDT as thermodynamically and dynamically favorable factors under low-intensity ultrasound irradiation, respectively. The NIR-phosphorescent CDs are identified as bipolar quantum dots containing both p- and n-type surface functionalization regions that can drive spatial separation of e--h+ pairs and fast transfer to reaction sites. Importantly, the cancer-specific targeting and high-level intratumor enrichment of the theranostic CDs are achieved by cancer cell membrane encapsulation for precision SDT with complete eradication of solid tumors by single injection and single irradiation. These results will open up a promising approach to engineer phosphorescent materials with long-lived triplet excited states for sonodynamic precision tumor therapy.

Circularly Polarized Luminescence of Achiral Carbon Dots in Bi-Solvent Systems Triggered by Supramolecular Self-Assembly.

An innovative strategy for circularly polarized luminescence (CPL) of carbon dots (CDs) has been developed: The achiral CDs displayed contrary supramolecular chirality and opposite CPL in two different bi-solvent systems, which are due to the formation of self-assembled helical nanostructures with two diverse assembly modes (P and M) in aggregate state via intermolecular π-π interactions and differential hydrogen bonding (H-bonding) without the need of any additional element of chirality.

Biomolecule-Based Circularly Polarized Luminescent Materials: Construction, Progress, and Applications.

Chiral materials related to circularly polarized luminescence (CPL) make up a rapidly developing new field that has broad application prospects in optoelectronic devices, selective recognition, biomedicine, and other fields. Biofunctional chiral materials are also attracting increasing attention because of their unique biocompatibility, chiral recognition, and coding. However, there has been little discussion on biomolecule-based CPL till now. In this Review, the latest progress in CPL materials related with biomolecules are reviewed, including the chiral construction from molecular level to giant microstructure, as well as their emerging applications. In addition, we discuss the challenges and prospects of bio-based CPL materials, hoping this work will provide new perspectives and insights for more related research.

2H-MoS2/Co3O4 nanohybrid with type I nitroreductase-mimicking activity for the electrochemical assays of nitroaromatic compounds.

A type I nitroreductase-mimicking nanocatalyst based on 2H-MoS2/Co3O4 nanohybrids for trace nitroaromatic compounds detection is reported in this work. For the preparation of nanocatalyst, ultrathin Co3O4 nanoflakes array was in-situ grown onto 2H-MoS2 nanosheets forming three-dimensional (3D) nanohybrid with large specific surface area as well as abundant active sites. The as-prepared nanocatalyst shows a specific affinity as well as high catalytic activity towards nitroaromatic compounds. Given the favorable nitroreductase-mimicking catalytic activity of 2H-MoS2/Co3O4 nanohybrid, a sensitive and efficient electrochemical microsensor has been constructed for the detection of 2, 4, 6-trinitrotoluene (TNT). Under optimized conditions, the microsensor displayed sensitive response from µM to pM levels with a limit of detection (LOD) of 1 pM. We further employed photoelectron spectroscopy (XPS) analysis and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method to identify the nitroreductase-mimicking mechanism of 2H-MoS2/Co3O4 nanohybrids towards 2, 4, 6- TNT. It was found that the abundant oxygen vacancies in ultrathin Co3O4 nanoflakes played an essential role in determining its catalytic performance. Moreover, the developed MoS2/Co3O4 nanozyme has a lower Michaelis-Menten constant (km) than that of nature nitroreductase demonstrating a good enzymatic affinity towards its substrates, and further generating a high catalytic activity. This research not only proposed a new type of nanozyme, but also developed a portable electrochemical microsensor for the detection of 2, 4, 6-TNT.

Design and Application of Metal Organic Framework ZIF-90-ZnO-MoS2 Nanohybrid for an Integrated Electrochemical Liquid Biopsy.

Limited healthcare capacity highlights the needs of integrated sensing systems for personalized health-monitoring. However, only limited sensors can be employed for point-of-care applications, emphasizing the lack of a generalizable sensing platform. Here, we report a metal organic framework (MOF) ZIF-90-ZnO-MoS2 nanohybrid-based integrated electrochemical liquid biopsy (ELB) platform capable of direct profiling cancer exosomes from blood. Using a bottom-up approach for sensor design, a series of critical sensing functions is considered and encoded into the MOF material interface by programming the material with different chemical and structural features. The MOF-based ELB platform is able to achieve one-step sensor fabrication, target isolation, nonfouling and high-sensitivity sensing, direct signal transduction, and multiplexed detection. We demonstrated the capability of the designed sensing system on differentiating cancerous groups from healthy controls by analyzing clinical samples from lung cancer patients, providing a generalizable sensing platform.

Correction: Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots.

Correction for 'Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots' by Yudai Liang et al., Soft Matter, 2022, DOI: 10.1039/D2SM00176D.

Cytidine-rich hydrogel as an electrochemical signal amplification strategy for microRNA detection.

Signal amplification strategies increase the complexities of biosensors while improving the response signals. Herein, a novel electrochemical biosensor was developed based on a DNA hydrogel for sensitive analysis using microRNA-21 (miRNA-21) as a detection model. Poly C sequences combined with C-Ag(I)-C hydrogel formed a DNA hydrogel by the unique interaction between the cytosines and silver ions. Thus, with a three-way conjunction structure of DNA, this C-Ag(I)-C hydrogel was constructed as a novel biosensor for the detection of miRNAs. With the assistance of this hydrogel, numerous silver ions gathered around DNA strands, which would amplify the signal. Under these conditions, the silver ions produced distinct square wave voltammetry oxidation peak currents. This electrochemical biosensor we designed exhibited a great linear relationship for the logarithm of the concentration of miRNA-21 from 1 fM to 100 pM with a detection limit of 0.117 fM. Furthermore, our sensors were able to differentiate miRNA-21 from its homologous family with satisfactory responsiveness in the dilute bovine serum system.

A molecular crowding thermo-switchable chiral G-quartet hydrogel with circularly polarized luminescence property.

A novel helix hydrogel with a G-quartet structure was synthesized from guanosine (Gua) and its derivative 5'-guanosine monophosphate (5'-GMP) under a molecular crowding environment. The chirality of the hydrogel is adjusted by controlling the gelling speed. The chiral hydrogel can induce an achiral dye Thioflavin T (ThT) to realize circularly polarized fluorescence (CPL). The CPL dissymmetry factor |glum| of the dye-hydrogels can reach 3 × 10-2 and can be switched easily.

Efficient and stable electrorheological fluids based on chestnut-like cobalt hydroxide coupled with surface-functionalized carbon dots.

Intrinsically polarized electrorheological fluids (ERFs) have better thermal stability than ERFs with polar molecules, so they have a broader application prospect. However, the electrorheological efficiency of the common intrinsically polarized ERF is still lower than 1500, which is related to the poor wettability between polarized materials and the continuous phase. Carbon dots (CDs) exhibit good stability, semiconductor properties and low toxicity. We prepared biomimetic chestnut-like cobalt hydroxide coupled with surface-functionalized CD particles (Co(OH)2@CDs) by a simple hydrothermal method. Then we prepared an ERF by mixing Co(OH)2@CDs with silicone oil and studied the effect of CDs on its rheology and electrorheology properties. The synergistic effect of the lipophilic groups on the surface of CDs and the biomimetic chestnut-like structure makes Co(OH)2@CDs exhibit good wettability with silicone oil, and the optimal zero-field viscosity of Co(OH)2@CDs-ERF is only 0.46 Pa s (particle mass fraction of 40%). Exceptional electrorheological efficiency (about 10 000, shear rate 0.1 s-1, 5 kV mm-1) and dynamic shear stress stability of optimal Co(OH)2@CDs-ERF can be attributed to the dielectric enhancement of the biomimetic chestnut-like structure coupled with the semiconductor properties of CDs. In addition, Co(OH)2@CDs-ERF has excellent anti-settling performance, outstanding thermal stability and low current density.

Study Design and Baseline Profiles of Participants in the Tianjin Birth Cohort (TJBC) in China.

BACKGROUND: To investigate the causal link between early-life exposures and long-term health consequences, we established the Tianjin Birth Cohort (TJBC), a large-scale prospective cohort in northern China. METHODS: TJBC aims to enroll 10,000 families with follow-ups from pregnancy until children's six year-old. Pregnant women and their spouses were recruited through a three-tier antenatal healthcare system at early pregnancy, with follow-ups at mid-pregnancy, late pregnancy, delivery, 42 days after delivery, 6 months after delivery, and each year until 6 years old. Antenatal/neonatal examination, biological samples and questionnaires were collected. RESULTS: From August 2017 to January 2019, a total of 3,924 pregnant women have already been enrolled, and 1,697 women have given birth. We observed the prevalence of gestational diabetes mellitus as 18.1%, anemia as 20.4%, and thyroid hypofunction as 2.0%. In singleton live births, 5.6% were preterm birth (PTB), 3.7% were low birth weight, and 7.3% were macrosomia. Based on current data, we also identified maternal/paternal factors which increased the risk of PTB, including paternal age (OR 1.07; 95% CI, 1.01-1.14 for each year increase), vaginal bleeding during pregnancy (OR 2.82; 95% CI, 1.54-5.17) and maternal early-pregnancy BMI (OR 1.08; 95% CI, 1.01-1.15 for each kg/m2 increase). CONCLUSION: TJBC has the strength of collecting comprehensive maternal, paternal, and childhood information. With a diverse range of biological samples, we are also engaging with emerging new technologies for multi-omics research. The study would provide new insight into the causal link between macro/micro-environmental exposures of early life and short/long-term health consequences.

1T-Phase molybdenum sulfide/cobalt oxide nanopillars hybrid nanostructure coupled with nitrogen-doped carbon thin-film as high efficiency electrocatalyst for oxygen evolution.

High efficient and durable catalysts are always needed to lower the kinetic barriers as well as prolong the service life associated with oxygen evolution reaction (OER). Herein, a sequential synthetic strategy is considered to prepare a hierarchical nanostructure, in which each component can be configured to achieve their full potential so that endows the resulting nanocatalyst a good overall performance. In order to realize this, well-organized cobalt oxide (Co3O4) nanopillars are firstly grown onto ultrathin 1T-molybdenum sulfide (1T-MoS2) to obtain high surface area electrocatalyst, providing electron transfer pathways and structural stability. After that, zeolitic imidazolate framework-67 (ZIF-67) derived carbonization film is further in situ deposited on the surface of nanopillars to generate plentiful active sites, thereby accelerating OER kinetics. Based on the combination of different components, the electron transfer capability, catalytic activity and durability are optimized and fully implemented. The obtained nanocatalyst (defined as 1T-MoS2/Co3O4/CN) exhibits the superior OER catalytic ability with the overpotential of 202 mV and Tafel slope of 57 mV·dec-1 at 10 mA·cm-2 in 0.1 M KOH, and good durability with a minor chronoamperometric decay of 9.15 % after 60,000 s of polarization.