In vivo effects of low dose prenatal bisphenol A exposure on adiposity in male and female ICR offspring.

BACKGROUND: Bisphenol A (BPA) is known to exhibit endocrine disrupting activities and is associated with adiposity. We examined the obesogenic effect of prenatal BPA exposure in the present study. METHODS: Pregnant ICR mice were exposed to vehicle or BPA via the drinking water at a dose of 0.5 µg/kg·d throughout the gestation. Obesity-related indexes were investigated in the 12-wk-old offspring. Primary mouse embryonic fibroblasts (MEFs) collected from treated embryos were used to test effects of BPA on adipocyte differentiation. RESULTS: Offspring presented a significantly higher rate of weight gain than the control, with impaired insulin sensitivity and increased adipocyte size. Differentiation of MEFs from BPA-treated mice showed a higher propensity for the adipocyte commitment as well as up-regulation of genes enriched in lipid biosynthesis. TGF-ß signaling pathway was found to modulate obesogenic effect of BPA in MEF model, but estrogen signaling pathway had no effect. CONCLUSIONS: The present study provides strong evidence of the association between prenatal exposure to low dose of BPA and a significant increase in body weight in the offspring mice with a critical role played by TGF-ß signaling pathway. The potential interactions modulating the binding of BPA and TGF-ß that activate its obesogenic effects need to be examined.

Aggregation emission of AuNCs induced by chitosan self-assembled multilayers and sensitive sensing for water content in ethanol.

AuNCs with chemical groups such as -NH2 and -COOH were synthesized using glutathione as the stabilizer and reducing agent. The aggregation emission of AuNCs in solution-induced self-assembled multilayers (SAMs) were first studied. Scanning electron microscopy and quartz crystal microbalance were used to characterize the morphology and aggregation process of AuNCs. Further AuNC SAMs were used for the solid-liquid interface sensing of water content in ethanol, and the sensitivity is obviously improved as compared with that in the pure solution phase. This aggregation emission induced by SAMs would have a good application prospect in analysis.

Water-soluble long afterglow carbon dots/silica composites for dual-channel detection of alkaline phosphatase and multi-level information anti-counterfeiting.

Water-soluble carbon dots/silica (CDs/SiO2) composites with an ultra-long lifetime of 846.9 ms and an ultra-high afterglow quantum yield of 12.1% were successfully obtained by incorporating CDs into a SiO2 network. Within the aqueous solution, the SiO2 layer isolates CDs from the surrounding oxygen. Meanwhile, hydrogen bonds and covalent bonds are formed between the CDs and SiO2, and these bonds restrict the movement and vibration of the CDs. Accordingly, the non-radiative inactivation rate of the triplet excitons of the CDs is reduced, thereby enhancing the room-temperature phosphorescence of the CDs and triggering thermally activated delayed fluorescence. The multiple properties of the material effectively protect the CDs from the external environment, making CDs/SiO2 emit a long afterglow in the solid and liquid phases. The prepared CDs/SiO2 composites have exceptional stability against strong oxidants, acids, bases, and polar solvents. The composites were successfully used in the dual-optical mode detection of alkaline phosphatase, as an anti-counterfeiting ink, and in multi-level information anti-counterfeiting and encryption.

Tandem Förster resonance energy transfer induced visual ratiometric fluorescence sensing of tetracyclines based on zeolitic imidazolate framework-8 incorporated with carbon dots and safranine T.

Developing new methods for efficiently detecting tetracycline antibiotics in water has gained much importance. In this work, zeolitic imidazolate framework-8 (ZIF-8) was used as a host to encapsulate carbon dots (CDs) and safranine T (ST) during its self-assembly process to synthesize CDs/ST@ZIF-8, which was then applied as the dual-emissive probe for detecting tetracycline antibiotics. Benefiting from the confinement effects of ZIF-8 and its fluorescence enhancement effects toward tetracycline (TC), a unique tandem Förster resonance energy transfer (FRET) system from CDs to TC and then to ST could be established, with a low limit of detection of 46 nM and excellent selectivity. More importantly, as compared to the CDs/ST system without tandem FRET, the sensitivity of the CDs/ST@ZIF-8 toward TC increased ∼69-fold, and naked eye recognition could also be achieved. Furthermore, by analyzing the R, G, and B values of photos containing different concentrations of tetracycline with the help of a mobile phone and correlating them with the concentration of tetracycline, we can perform the on-site detection of tetracycline, which is convenient, fast, and accurate. This study shows that new insight can be gained for the rational design and application of ratiometric fluorescence sensors based on tandem Förster resonance energy transfer in metal-organic framework materials.

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.

Corrigendum to "Cobalt metal-organic framework modified carbon cloth/paper hybrid electrochemical button-sensor for nonenzymatic glucose diagnostics" [Sens. Actuators B Chem. 329 (2021) 129205].

[This corrects the article DOI: 10.1016/j.snb.2020.129205.].

A Multi-Catalytic Sensing for Hydrogen Peroxide, Glucose, and Organophosphorus Pesticides Based on Carbon Dots.

In this work, a facile one-pot hydrothermal route was employed to synthesize a series of fluorescent carbon dots (CDs) by using 20 natural amino acids, respectively, as the starting materials. It was found that the CDs synthesized using phenylalanine could possess the intrinsic peroxidase-like activity that could effectively catalyze a traditional peroxidase substrate like 3, 3', 5, 5'- tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue solution; thereby, a catalytic sensing system for H2O2 has been developed. On the basis of this catalytic reaction, together with the fact that glucose oxidase (GOx) can catalyze the hydrolysis of glucose to generate H2O2, a sensitive catalytic sensing system for glucose could be further established. Furthermore, based on this catalytic reaction, taken together with the two enzymatic catalytic systems of acetylcholinesterase (AChE) and choline oxidase (CHO), a highly sensitive multi-catalytic sensing system could be successfully developed for organophosphorus (OPs) pesticides such as dimethoate, DDVP, and parathion-methyl. Limit of detections (LODs) of H2O2 and glucose were estimated to be 6.5 and 0.84 µM, respectively. The limit of detection of the sub-nM level could be obtained for tested dimethoate, DDVP, and parathion-methyl OPs pesticides. The established sensing systems can exhibit good practical application performance in serum and several fruit samples.

Self-Assembled Multivalent Ag-SR Coordination Polymers with Phosphatase-Like Activity.

We show herein the phosphatase-like catalytic activity of coordination polymers obtained after adding Ag+ -ions to thiols bearing hydrophobic alkyl chains terminated with a 1,4,7-triazacyclononane (TACN) group. The subsequent addition of Zn2+ -ions to the self-assembled polymers resulted in the formation of multivalent metal coordination polymers capable of catalysing the transphosphorylation of an RNA-model compound (2-hydroxypropyl-4-nitrophenyl phosphate, HPNPP) with high reactivity. Analysis of a series of metal ions showed that the highest catalytic activity was obtained when Ag+ -ions were used as the first metal ions to construct the backbone of the coordination polymer through interaction with the -SH group followed by Zn2+ -ions as the second metal ions complexed by the TACN-macrocycle. Furthermore, it was demonstrated that the catalytic activity could be modulated by changing the length of the hydrophobic alkyl chain.

Cobalt metal-organic framework modified carbon cloth/paper hybrid electrochemical button-sensor for nonenzymatic glucose diagnostics.

In the growing pandemic, family healthcare is widely concerned with the increase of medical self-diagnosis away from the hospital. A cobalt metal-organic framework modified carbon cloth/paper (Co-MOF/CC/Paper) hybrid button-sensor was developed as a portable, robust, and user-friendly electrochemical analytical chip for nonenzymatic quantitative detection of glucose. Highly integrated electrochemical analytical chip was successfully fabricated with a flexible Co-MOF/CC sensing interface, effectively increasing the specific area and catalytic sites than the traditional plane electrode. Based on the button-sensor, rapid quantitative detection of glucose was achieved in multiple complex bio-matrixes, such as serum, urine, and saliva, with desired selectivity, stability, and durability. With the advantages of low cost, high environment tolerance, ease of production, our nanozyme-based electrochemical analytical chip achieved reliable nonenzymatic electrocatalysis, has great potential for the application of rapid on-site analysis in personalized diagnostic and disease prevention.

MoS2 quantum dots as a specific fluorescence sensor for selection of rutin and for temperature sensing.

A selective and sensitive method for detecting rutin using MoS2 quantum dots (QDs) as a fluorescent probe is reported in the paper, a one-step hydrothermal synthesis method was used to prepare MoS2 QDs. The synthesized MoS2 QDs had good stability and water solubility, and the fluorescence of MoS2 QDs was quenched by rutin due to the inner filter effect. There was a good linear relationship between the intensity of MoS2 QDs and rutin concentration ranging from 5.0 × 10-7 to 3.2 × 10-5 mol/L with a detection limit of 3.5 × 10-7 mol/L. MoS2 QDs showed temperature-dependent fluorescence that had an excellent linear relationship between 20 and 80°C. Therefore MoS2 QDs can be used as specific fluorescence sensors for selection of rutin and for temperature sensing.

Chromatin-enriched RNAs mark active and repressive cis-regulation: An analysis of nuclear RNA-seq.

Long noncoding RNAs (lncRNAs) localize in the cell nucleus and influence gene expression through a variety of molecular mechanisms. Chromatin-enriched RNAs (cheRNAs) are a unique class of lncRNAs that are tightly bound to chromatin and putatively function to locally cis-activate gene transcription. CheRNAs can be identified by biochemical fractionation of nuclear RNA followed by RNA sequencing, but until now, a rigorous analytic pipeline for nuclear RNA-seq has been lacking. In this study, we survey four computational strategies for nuclear RNA-seq data analysis and develop a new pipeline, Tuxedo-ch, which outperforms other approaches. Tuxedo-ch assembles a more complete transcriptome and identifies cheRNA with higher accuracy than other approaches. We used Tuxedo-ch to analyze benchmark datasets of K562 cells and further characterize the genomic features of intergenic cheRNA (icheRNA) and their similarity to enhancer RNAs (eRNAs). We quantify the transcriptional correlation of icheRNA and adjacent genes and show that icheRNA is more positively associated with neighboring gene expression than eRNA or cap analysis of gene expression (CAGE) signals. We also explore two novel genomic associations of cheRNA, which indicate that cheRNAs may function to promote or repress gene expression in a context-dependent manner. IcheRNA loci with significant levels of H3K9me3 modifications are associated with active enhancers, consistent with the hypothesis that enhancers are derived from ancient mobile elements. In contrast, antisense cheRNA (as-cheRNA) may play a role in local gene repression, possibly through local RNA:DNA:DNA triple-helix formation.

Gold nanodendrite-based differential potential ratiometric sensing strategy for enantioselective recognition of DOPA.

Numerous chiral drugs have been developed for neurological diseases, but chiral drug safety and pharmacological research still faces great challenges in enantioselectivity and sensitivity of chiral analysis. A rapid, stable and high-efficiency gold nanodendrite-based electrochemical sensing method was proposed as a versatile differential potential ratiometric strategy for highly selective chiral recognition of dual 3,4-dihydroxyphenylalanine (DOPA) enantiomers. Using simple electrochemical deposition, the gold nanodendrite (AuND) membrane was steadily modified on the glassy carbon electrode (GCE) with high specific chiral identifiability and robust signal amplifiability. Based on a sequence of systematic optimization, an apparent potential difference (PD) was detected up to 108 mV from oxidation peaks of DOPA enantiomers. Furthermore, according to a regulatable concentration range from 10 µM to 100 µM, different proportions of L-/d-DOPA had a good linear relationship with corresponding peak potentials (Eps) in the racemic mixture. Superior to traditional enantiorecognition of single chiral drug, both DOPA enantiomers enabled to be simultaneously distinguished with high repeatability, selectivity, and anti-interference ability on the AuND/GCE. This unique semi-quantitative AuND-based potential sensing strategy was proposed to efficiently quantify the proportion of L-/d-DOPA for chiral drug recognition, emerging positive potential for numerous applications in pharmacology and clinical diagnosis.

A solvatochromic AIE tetrahydro[5]helicene derivative as fluorescent probes for water in organic solvents and highly sensitive sensors for glyceryl monostearate.

In this paper, a tetrahydro[5]helicene-based imide dye with thienyl group (THID) was studied on its solvatochromism and aggregation-induced emission (AIE) properties by dissolved in various organic solvents. The linear relationship between Stokes shift and aprotic solvent polarity parameter was well fitted with Lippert-Mataga model. Furthermore, Stokes shift also were positively correlated with the normalized molar electronic transition energy, suggested that THID exceptionally depends on solvent polarity for twisted intramolecular charge transfer. In addition, THID demonstrated typical AIE features when adding large amounts of water into good solvent. Meanwhile, it can function as intensity and wavelength-based fluorescence sensor for detecting low-level water content in water soluble solvents, even the low of detection was 0.014 vol% in ACN. Therefore, a simple and highly selective fluorescence analysis for glyceryl monostearate has been established on basis of its AIE property.

A label-free "SEF-FRET" fluorescent sensing platform for ultrasensitive DNA detection based on AgNPs SAMs.

In this paper, deoxyribonucleic acid (DNA) with different lengths were used to control the distance between carbon dots (CDs) and silver nanoparticles (AgNPs) in self-assembled multilayers (SAMs). Surface-enhanced fluorescence and fluorescence resonance energy transfer (SEF-FRET) could be achieved based on changing DNA strands. The fluorescence intensity of CDs SAMs with 6-base DNA strands could be enhanced up to ca. 5.6 times by AgNPs. As-fabricated CDs SAMs with excellent luminescent properties, superior stability have been employed for the development of a label-free fluorescence sensing platform for DNA detection. Since DNA would hybridize with the complemented one which was attached on the surface of SAMs, resulting in a close distance between CDs and AgNPs, FRET could thus occur between AgNPs and CDs, resulting in quenching the fluorescence of CDs SAMs. This sensitive sensing platform could show excellent analytical performance for detecting DNA with a linear response ranging from 93.07 pM to 5.433 nM and a detection limit of 16.36 pM, which could be further employed to probe human blood samples. This could prove a promising method for the detection of DNA.

Luminescent carbon nanodots based aptasensors for rapid detection of kanamycin residue.

Despite the success in long-term storage of food and dietary products using antibiotics as supplements, enormous levels of their residues have remained as a significant health concern, leading to severe toxicity issues on consumption. Herein, we report an ultrasensitive and highly selective aptasensor based on carbon nanoparticles (CNPs) through a fluorescence-based aptamer-linked immunosorbent assay (FALIA) for rapid detection of kanamycin (KAA) residue. The fabricated CNP-aptasensor exhibited superior selectivity with exceptional photoluminescence properties. Under the optimal conditions, the linear equation of standard KAA solution was Y = -0.2279LogX+1.3648 (R = -0.9893) ranged from 10-4 to 10-7 ppb with excellent relative standard deviations (RSD) between 3.12 and 5.59 % (n = 3). Moreover, the limit of detection (LOD) was lower than 5.0 × 10-8 ppb. Together, the excellent recovery and significant efficacy in the rapid detection of antibiotics at a low level in milk indicate that this fabricated CNP-aptasensor has a great potential in the establishment of an efficient antibiotic detector system in food and other nutraceutical industries.

Rh(III)-Catalyzed Sequential C-H Amination/Annulation Cascade Reactions: Synthesis of Multisubstituted Benzimidazoles.

An efficient and practical method to construct benzimidazoles via Rh(III)-catalyzed sequential C-H amination and annulation cascade reaction has been developed. The cascade reaction displays high step, atom, and redox economy, is compatible with the air, and has good functional group tolerance and high efficiency. The titled products can be easily further converted into imidazo[4,5-c]acridines, which were observed unique fluorescent properties.

Carbon nanoparticles with oligonucleotide probes for a label-free sensitive antibiotic residues detection based on competitive analysis.

Carbon nanoparticles (CNPs) have been combined with aptamer, providing a broad application in small molecule. CNPs can be quenched by small molecules and are usually applied as luminescent probes because of their photophysical characteristics. In this work, we developed a competitive analysis for antibiotic residues detection based on carbon nanoparticles (CNPs) and oligonucleotide probes. Oligonucleotide probes including oxytetracycline (OTC) aptamer was exploited for recognition OTC and was used to restore the luminescence. Tetracycline (TC), as a competitor of OTC, was utilized to quench the luminescence of CNPs and reduce the sample matrix effect. Under optimal conditions, the linear rang of OTC was 0.010~1.0 ng/mL with the relative standard deviations (RSDs) from 2.91% to 11.3%, and the limit of detection (LOD) was low to 0.002 ng/mL. Moreover, the proposal was successfully applied to analyze OTC from drink water, indicating that this approach has great potential for other small molecule analysis.

Differential potential ratiometric sensing platform for enantiorecognition of chiral drugs.

A versatile, robust and efficient differential potential ratiometric sensing platform was developed for enantioselective recognition of dual chiral targets based on a composite membrane of molecularly imprinted polymers (MIPs) and reduced graphene oxide (rGO) modified glassy carbon electrode (GCE). The functional chitosan-based MIPs and rGO were compatibly immobilized on the GCE with high selectivity and efficient signal amplification. Moreover, via the systematic optimization of series conditions, a distinct potential difference (PD), reaching 135 mV, was obtained between the R-/S-prop based on the MIPs/rGO/GCE. In a controllable concentration range from 50 µM to 1000 µM, different ratios of R-/S-prop were linearly related to the peak potentials (Eps) in the racemic mixture. Using this low-cost reversible electrochemical platform, both Prop enantiomers were simultaneously identified with high repeatability and time-based stability. This novel semi-quantitative electrochemical sensing platform was established to rapidly quantify the ratio of S-/R-prop by Ep for the chiral drug recognition with great potential for practical applications in fields of pharmacological detection and clinical analysis.

Plasma microRNA: A novel non-invasive biomarker for HBV-associated liver fibrosis staging.

The aim of the present study was to evaluate the potential use of 7 plasma miRNAs for liver fibrosis staging in patients with chronic hepatitis B virus (HBV) infection. Relative levels of miRNAs were measured using quantitative polymerase chain reaction and used to develop a diagnostic panel. A receiver operating characteristic (ROC) curve was drawn to evaluate the performance of individual miRNAs and the whole panel. It was identified that hsa-miR-122 exhibited significantly different expression levels between F4 and F3, F2, F1, and F0 fibrosis stages (P<0.05), and between F2 and F1 stages (P=0.045); hsa-miR-146a-5p, hsa-miR-29c-3p and hsa-miR-223 exhibited significantly different expression levels between F4 and F0 stages. ROC analysis revealed that hsa-miR-122-5p, hsa-miR-223 and hsa-miR-29c-3p identified patients with ≥F2 fibrosis with area under the curve (AUC) =0.745, 0.631 and 0.670, respectively. hsa-miR-122-5p identified patients with ≥F3 disease (AUC=0.783). hsa-miR-122-5p, hsa-miR-223 and hsa-miR-29c-3p identified patients with cirrhosis with AUC=0.776, 0.617 and 0.619, respectively. The miRNA panel exhibited a higher accuracy compared with individual miRNAs in discriminating between ≥F2, ≥F3 and F4 fibrosis stages with AUC=0.904, 0.889 and 0.835, respectively. hsa-miR-122-5p, hsa-miR-146a, hsa-miR-29c and hsa-miR-223 were positively correlated with fibrosis stage. hsa-miR-122-5p and hsa-miR-381-3p were negatively correlated with alanine aminotransferase, aspartate transaminase and HBV viral DNA load. These 7 miRNAs may serve as potential biomarkers of liver fibrosis in patients with HBV-associated fibrosis. The miRNA panel may serve as a novel non-invasive method for liver fibrosis staging.

Diverse applications of TMB-based sensing probes.

Extending the research on 3,3',5,5'-tetramethylbenzidine (TMB) and its derivatives in analytical chemistry is important, considering that TMB is widely used as an enzyme catalytic substrate. In this work, two TMB derivatives, TMBS and TMBB, were synthesized via a facile and one-step condensation reaction between the -NH2 group of TMB and the -CHO group of salicylaldehyde or benzaldehyde. Because at low pH the two Schiff base compounds can release TMB which can emit strong fluorescence, the probes could show dual-modal signal responses, fluorescence and UV-vis absorption, towards the pH. Practical applications of pH sensing in Chinese rice vinegar and lemon juice samples were successfully demonstrated. On the basis of these findings, a catalytic chromogenic reaction was developed to monitor the pH with the naked eye, too. Furthermore, considering the chemical equilibrium reaction between CO2 and H2O and that glucose oxidase (GOD) can catalyse the dehydrogenation and oxidation reaction of ß-d-glucose to produce gluconic acid, both of which can result in lowering the pH values of the two Schiff base systems, highly sensitive and selective dual-modal sensing systems for detecting CO2 and ß-d-glucose have also been successfully established. Therefore, the two synthesized TMB derivatives can demonstrate their robust application potential.