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Chemiluminescence (CL) has been widely used for bioanalysis owing to its high sensitivity, low background and simplicity. However, most of the CL systems need acidic/alkaline conditions or organic solvent to enhance their luminescent efficiency, and the non-physiological conditions can usually lead to the misfunction of biomolecules during biosensing. Herein, we report a highly luminous CL system under physiological conditions based on carbon dots-bis(2-carbopentyloxy-3,5,6-trichlorophenyl) oxalate (CDs-CPPO) micelles, and further used it in biosensing application. In the CL system, the amphiphilic surfactant packed CPPO and hydrophobic CDs together to form CDs-CPPO micelles. Such micelles solution not only isolated the CPPO from water to prevent its hydrolysis but also made the close proximity between CPPO and CDs, thus significantly enhancing the CDs quantum yield. The CL quantum yield was calculated to be 5.26 × 10−4 einsteins/mol, about 200-fold higher than that of the most commonly used luminol CL system. The oxidases (e.g., glucose oxidase) were tested to be susceptible to the organic solvent and non-physiological pH. Hence, the CL system was used for the detection of oxidase substrates (exemplified by glucose) in serum samples, and the limit of detection was as low as 8.4 nmol/L. The highly luminous CL system that can work under physiological conditions is promising for biosensing applications

A new method based on the enantioselective recognition of porous organic cages CC3-R was established for the first time. Porous organic cages are widely used for separation, adsorption and host-guest interaction sensing, but are rarely used for fluorescence sensing. Based on the inherent chiral environment of CC3-R and the inherent fluorescence properties of the organic ligands constituting the cage, when different chiral monomers diffuse into the cage, different effects occur to produce changes in fluorescence. We found for the first time that the fluorescence of CC3-R can be enhanced and quenched by tyrosine and mandelic acid, respectively, and that different chiral monomers are enhanced or quenched differently at the same concentration. Unlike the chiral recognition of other composite luminescent materials, the chiral porous organic cage not only utilizes its own host-guest effect for chiral recognition, but also utilizes the organic ligands constituting the cage for luminescence recognition. This work provides an alternative method to accomplish chiral recognition other than chromatography, that is using porous organic cages (POC), but it can show the advantages of simplicity, low cost and high sensitivity. We believe this work could provide valuable thoughts in the exploration of POC in chiral recognition as new FL probes for the future.

Photosensitization, originated from the activation of triplet states, is the basis of many photodynamic applications, but often competes with a series of nonradiative processes. Herein, we communic...

Hirotaka Kanzaki,1 Avradip Chatterjee,1 Hanieh Hossein Nejad Ariani,1 Xinfeng Zhang,2 Stacey Chung,2 Nan Deng,3,4 V Krishnan Ramanujan,4 Xiaojiang Cui,1,2,4 Mark I Greene,5 Ramachandran Murali1 1Department of Biomedical Sciences, Research Division of Immunology; 2Department of Surgery; 3Biostatistics and Bioinformatics Research Center; 4Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA; 5Department of Pathology and Laboratory of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USACorrespondence: Ramachandran Murali Email ramachandran.murali@csmc.eduIntroduction: Constitutive activation of NF-κB has been implicated as being contributive to cancer cell growth, drug resistance, and tumor recurrence in many cancers including breast cancer. Activation of NF-κB leads to nuclear translocation of RelA, a critical component of the NF-κB transcription factor complex, which subsequently binds to specific DNA sites and activates a multitude of genes involved in diverse cell functions. Studies show that triple-negative breast cancer (TNBC) cells possess constitutively active NF-κB and concomitantly have higher levels of nuclear localization of RelA than cytoplasmic RelA. This feature is considered to be associated with the response to chemotherapy. However, currently, there is no specific inhibitor to block nuclear translocation of RelA.Methods: A structure-based approach was used to develop a small-molecule inhibitor of RelA nuclear translocation. The interaction between this molecule and RelA was verified biophysically through isothermal titration calorimetry and microscale thermophoresis. TNBC cell lines MDA-MB-231 and MDA-MB-468 and a human TNBC xenograft model were used to verify in vitro and in vivo efficacy of the small molecule, respectively.Results: We found that the small molecule, CRL1101, bound specifically to RelA as indicated by the biophysical assays. Further, CRL1101 blocked RelA nuclear translocation in breast cancer cells in vitro, and markedly reduced breast tumor growth in a triple-negative breast cancer xenograft model.Conclusion: Our study demonstrates that CRL1101 may lead to new NF-κB-targeted therapeutics for TNBC. Further, blocking of nuclear translocation of shuttling transcription factors may be a useful general strategy in cancer drug development.Keywords: transcription factors, breast cancer, computer aided drug design, nuclear transport, drug-target

Dasatinib, a tyrosine kinase inhibitor, has a protective effect on experimental acute respiratory distress syndrome (ARDS). This study investigated the effect and mechanism of dasatinib in ARDS. C57BL/6 mice were administered with dasatinib (1 and 10 mg/kg) after lipopolysaccharide (LPS) treatment to evaluate the effect of dasatinib on white blood cells (WBC), neutrophils, lymphocytes and macrophages in bronchoalveolar lavage fluid (BALF). The levels and mRNA expressions of inflammation-related cytokines in lung tissues and RAW 264.7 cells were detected by enzyme-linked immunosorbent assay and quantitative real-time PCR, respectively. The protein expressions of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase 1 (HO1) were determined by Western blot. MTT assay was performed to detect the viability of RAW 264.7 cell. Rescue experiments were used to assess the effect of Nrf2 silencing on the LPS- and dasatinib-treated mice. Under LPS treatment, levels of the WBC, neutrophils, lymphocytes and macrophages in BALF and mRNA expressions of IL-6, TNF-α and IL-10 as well as expression of iNOS were increased, but the expression of arginase-1 was inhibited, while no obvious changes of the protein expressions of Nrf2 and HO1 were observed. Dasatinib partially reversed the effects of LPS above, and further promoted the mRNA expression of IL-10 and the protein expressions of Nrf2 and HO1, while Nrf2 silencing counteracted the effect of dasatinib. Dasatinib induced the polarization of M2 subtype of macrophages and alleviated LPS-induced ARDS through activating Nrf2 signaling pathway, which may provide a new strategy for the treatment of ARDS.

Polyhedral oligomeric silsesquioxanes (POSS) and γ-glycidoxy propyl trimethoxy silane (KH560) were applied to modify boron nitride (BN) and boron nitride whisker (BNw), and modified BN (m-BN) and m...

The development of efficient solar driven catalyst for the degradation of antibiotics has become increasingly important in environmental protection. However, the reported efficient photocatalysts for antibiotic degradation are limited. In this work, porous Fe3+-doped graphitic carbon nitride (g-C3N4) with outstanding photocatalytic ability is synthesized and then used as the photocatalyst for the efficient degradation of sulfadiazine (SDZ) under visible light. A series of characterization results indicate that Fe3+ is successfully doped into the interlayer of g-C3N4 and is stabilized in g-C3N4 by Fe-N coordination bond. The SEM, DRS and ESI and transient photocurrent results demonstrated that Fe3+-doped g-C3N4 has a porous structure, a low band gap, improved separation efficiency of photogenerated electron and holes as well as a wider light absorption range. Such improved physical and chemical properties greatly enhanced the photocatalytic ability. Using Fe3+-doped g-C3N4 for photocatalytic degradation of SDZ under white light, almost complete degradation of SDZ was achieved with a degradation efficiency as high as 99.8% (whereas only 52.1% for bulk g-C3N4) within 90 min. The degradation was mainly ascribe to 1O2 during the irradiation, and also a small amount of •O2−, OH• and h+ are involved in the degradation process. The Fe3+-doped g-C3N4 was applicable for the degradation of a wide range of antibiotic pollutants.

Polymer-derived SiCN ceramics containing cobalt was prepared with SiCN ceramics as matrix and cobalt nanoparticles as doping phase. Phase composition, Raman analysis, electromagnetic parameters and microwave absorption properties of SiCN ceramics with different cobalt content pyrolyzed at 1100 ℃ and cobalt content of 2 wt% but different pyrolysis temperature were carried out. The microstructures and magnetic properties of SiCN ceramics with cobalt content of 2 wt% and pyrolysis temperature of 900 ℃ were analyzed. The results show that some cobalt particles can react with carbon to form magnetic Co3C particles, which is one of the reasons for the magnetism of the sample. The good dielectric property of SiCN ceramics matches the magnetic property, which makes the material have excellent microwave absorption property. When the cobalt content is 2 wt% and the pyrolysis temperature is 900 ℃, the sample has the best microwave absorption performance. The minimum RL reaches − 10.9 at about 15 GHz, and the effective absorption bandwidth (RL < − 10 dB) is 3.3 GHz with a thickness of 3 mm. When the thickness became 6 mm, the minimum RL of the sample can reach − 11.8 dB and the effective absorption bandwidth (RL < − 10 dB) is 4.2 GHz, showing the excellent microwave absorption performance of materials we obtained.

A novel genotoxicity sensor was developed based on the base repair process associated with the electrochemiluminescence (ECL) detection of abasic sites in a double-stranded DNA monolayer. This is the first time that an ECL sensor with the ability to identify the removed nucleobases in a DNA duplex has been studied. The successful detection of abasic sites created by DNA glycosylase indicates its further applications for examining some other specific types of DNA damage.

In quantum-dots-converted white-light-emitting diodes (QDs-WLEDs), red-emitting quantum dots are usually mixed with yellow-emitting phosphors in luminescent polymer layer to achieve a high color re...

Graphitic carbon nitride (g-C3N4), as a visible-light-active organic semiconductor, has attracted growing attentions in photocatalysis and photoluminescence-based biosensing. Here, we demonstrated the intrinsic photooxidase activity of g-C3N4 and then surface molecular imprinting on g-C3N4 nanozymes was achieved for improved biosensing. Upon blue LED irradiation, the g-C3N4 exhibited superior enzymatic activity for oxidation of chromogenic substrate like 3,3′,5,5′-tetramethylbenzidine (TMB) without destructive H2O2. The oxidation was mainly ascribed to O2− that was generated during light irradiation. The surface molecular imprinting on g-C3N4 can lead to an over 1000-fold alleviation in matrix-interference from serum samples, 4-fold improved enzymatic activity as well as enhanced substrate specificity comparing with bare g-C3N4 during colorimetric sensing. Also, the MIP-g-C3N4 possesses a high affinity to TMB with a Km value of only 22 μmol/L, much lower than other comment nanozymes like AuNPs, Fe3O4 NPs, etc. It was successfully applied for detection of cysteine in serum sample with satisfactory recoveries.

Exonuclease III (Exo III) is an important enzymatic tool that is being widely used in molecular biology, biotechnology, and bioassay development. Exo III prefers to cleave double-stranded DNA (dsDNA) with blunt and recessed 3'-termini rather than their protruding counterpart. While it has been accepted that a short 3'-overhang (e.g., >4 nt) is necessary to protect a dsDNA from Exo III cleavage, critical roles of the length and sequence of this 3'-overhang remain unexplored. Herein, we develop a novel light-induced colorimetric assay allowing the systematic probe of the sequence selectivity of Exo III in a rapid and high-throughput manner. Our finding that Exo III is highly specific to 3'-overhang in terms of both length and sequence will be valuable for guiding the design of bioassays and DNA manipulating tools mediated by Exo III.

We cloned a new gene from the amidase signature (AS) family, designated am , from the marine actinomycete Salinispora arenicola CNS-205. As indicated by bioinformatics analysis and site-directed mutagenesis, the AM (a gene encoding a putative amidase) protein belonged to the AS family. AM was expressed, purified, and characterised in Escherichia coli BL21 (DE3), and the AM molecular mass was determined to be 51 kDa. The optimal temperature and pH were 40 °C and pH 8.0, respectively. AM exhibited a wide substrate spectrum and showed amidase, aryl acylamidase, and acyl transferase activities. AM had high activity towards aromatic and aliphatic amides. The AM substrate specificity for anilides was very narrow, and only propanil could be used as an effective substrate. The extensive substrate range of AM indicates it may have broad potential applications in biosynthetic processes and biodegradation.

Singlet oxygen, generated from type-II photosensitization, has become increasingly popular in bioassay development in recent years. However, the transient nature of singlet oxygen in water (lifetime shorter than 4 μs) as well as its high activity make it easily inactivated by solvent molecules and other coexisting species, thus deteriorating use in the analytical sensitivity. Here, we proposed the use of a simple redox mediator for storing the energy of the transient singlet oxygen. To demonstrate such an idea, singlet oxygen generated from photosensitization of the double strand DNA-SYBR Green I (dsDNA-SG) complex was explored as a redox donor that can be modulated through formation and deformation of the dsDNA structure. After screening of a series of redox mediators with luminol chemiluminescence (CL) as the probe, ferrocyanide (K4Fe(CN)6) was found to be the most efficient, resulting in ∼30-fold intensified luminol CL. By storing the oxidative capacity of singlet oxygen in ferrocyanide, the dsDNA-SG complex was evolved into a photosensitization-mediated chemiluminescence (PMCL) biosensing platform for DNA detection. Such a PMCL sensing platform allows label- and amplification-free detection of picomolar-scale DNA with a limit of detection (LOD) of 1.5 pM (0.45 fmol in absolute). The excellent sensitivity of PMCL sensing confirmed that such a facile storage approach to oxidative capacity would be appealing for singlet-oxygen-involved biosensing.

Triplet exciton formation is essential for photosensitization-based photochemistry and photobiology. The heavy atom effect (HAE), in the form of either external or internal mode, is a basic mechanism for increasing the triplet exciton yield of photosensitizers. Herein, we report a new HAE mode by noncovalent cohosting of heavy atoms and photosensitizers in a double-stranded DNA (dsDNA) matrix. With dsDNA bearing several thymine (T) or cytosine (C) mismatches, heavy atoms (e.g., Hg2+ or Ag+) and dsDNA-staining dyes (photosensitizers) were spatially adjoined in close proximity, thus resulting in enhanced phosphorescence and 1O2 generation from the photosensitizers. The dsDNA-hosted HAE provides highly selective recognition for the heavy atoms, which is not applicable in either the external or the internal mode. Considering the simpleness and efficiency of the spatially adjoined HAE, as well as the functionality of DNA, the proposed HAE mode is appealing for various singlet oxygen- and phosphorescence-related applications.

Graphitic carbon nitride (g-C3N4) as an outstanding photoresponsive nanomaterial has been widely used in biosensing. Other than the conventional single channel sensing mode, a triple-channel sensing array was developed for high discrimination of proteins based on the photoresponsive g-C3N4. Besides the photoluminescence and Rayleigh light scattering features of g-C3N4, we exploit the new photosensitive colorimetry of g-C3N4 as the third channel optical input. The triple-channel optical behavior of g-C3N4 can be synchronously changed after interaction with the protein, resulting in the distinct response patterns related to each specific protein. Such a triple-channel sensing array is demonstrated for highly discriminative and precise identification of nine proteins (hemoglobin, trypsin, lysozyme, cytochrome c, horseradish peroxidase, transferrin, human serum albumin, pepsin, and myoglobin) at 1 μM concentration levels with 100% accuracy. It also can discriminate proteins being present at different concentration and protein mixtures with different content ratios. The practicability of this sensor array is validated by high accuracy identification of nine proteins in human urine samples. This indicates that the array has a great potential in terms of analyzing biological fluids.

An increasing number of patients are living with Alzheimer's disease (AD); thus, the need for a method to detect AD early and sensitively has become urgent, and the demand for an intelligent analytical platform is growing year by year. Abnormal levels of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are known to be indicative of AD. In this work, a novel conjugated polythiophene (CP) compound was successfully combined with CdTe quantum dots (QDs) to improve their selectivity and sensitivity. The QDs successfully enabled the detection of low concentrations of AChE by turning on the fluorescence of the CdTe/CP via the interaction between CP and thiocholine produced by ATCh hydrolysis and aggregation induced emission enhancement (AIEE). Under optimal conditions, we reached a low detection limit of 0.14 U L-1, which is 7.9 times lower than that of pristine QDs. More importantly, an efficient, inexpensive, and disposable paper-based platform, which allows the efficient visual detection of AChE activity via the color variation of CdTe/CP, was designed. Moreover, the accuracy of the method was demonstrated by conducting a recovery test in human serum, in which the recoveries reached 107% and 110%, proving that CdTe/CP has considerable potential to be used for analyzing real biological samples. The advantages of this method are its simplicity, fast detection capability, affordability, and the fact that it can be used for on-site detection of AChE activity. Furthermore, it has certain guiding significance for detecting AD.

The quantification of proteins is essential in fundamental research or clinical applications. Here, we developed a facile electrochemical aptasensor based on target-induced turn-off of photosensitization for label-free and ultrasensitive detection of protein (exemplified by lysozyme). EB (ethidium bromide) molecules that were embedded in dsDNA between lysozyme binding aptamer and complementary DNA immobilized on the electrode, could photo-cleave the dsDNA via singlet oxygen (O21) during photosensitization, resulting in a high voltammetry current of the [Fe(CN)6]3-/4-. Upon recognition of the lysozyme by aptamer, the EB molecules were released from dsDNA, and its photosensitization activity was turned off. As a result, more amount of complementary DNA was retained on the Au nanoparticles modified carbon nanotube paste electrode (AuNPs-CNPE), leading to a declined voltammetry current. Such a sensing strategy allowed detection of 10 pM-1 µM lysozyme with a low detection limit (about 2 pM). Besides, the sensor was free of labeling procedure as well as extra signal amplification step, and the CNPE modification was quite simple, only with AuNPs. The sensor also showed excellent selectivity toward lysozyme in the presence of interfering proteins, such as thrombin, bovine serum albumin, myoglobin, etc. The proposed sensor was applied to the determination of lysozyme in urine samples with the recoveries ranging from 96.6% to 101%. The proposed biosensor holds a great promise in developing other electrochemical sensors based on photosensitization.

DNAzyme that can catalytically cleave of substrate DNA has shown to be attractive for amplified detection in biosensing events. During the catalytic process, the recycling of enzyme strand of DNAzyme is critically important. In this work, a G-quadruplex-assisted enzyme strand recycling strategy was developed for amplified label-free fluorescent detection of uranyl ion (UO22+). The DNAzyme was activated by the target UO22+ and further cleaved the substrate strand that contained the G-quadruplex sequence. The following formation of G-quadruplex helps the separation between the enzyme strand and the cleaved substrate strand, thus improving the recycle use of the enzyme strand. Such strategy allowed lablel-free detection of 0.2–200 ng/mL UO22+ via SYBR green I (SG)-based fluorescence. The detection limit (3δ) is as low as 0.06 ng/mL (about 0.2 nmol/L), comparable to those obtained by ICP-MS and labeled DNAzyme. It was applied for detection of UO22+ in spiked environmental water samples with recoveries in the range of 96%–103%. This biosensor, with the advantages of simplicity and high sensitivity, is an appealing tool for fast detection of UO22+ in environmental water samples.

The bud of Dendranthema lavandulifolium (Jumi) is a featured agricultural product in Zhejiang Province (China) with active effects on liver detoxing and vision improvement. In order to evaluate the quality and identify geographical origin of Jumi, a high performance liquid chromatography (HPLC) chemical fingerprinting method was developed for simultaneous detection of multi-target components. Among the 16 common peaks in the fingerprint, 6 phenylpropanoids, 5 flavonoids and 2 volatile compounds were identified through combinational analytical applications of ultraviolet spectrum (UV), nuclear magnetic resonance spectroscopy (NMR), liquid chromatography–mass spectrometry (LC–MS) and gas chromatography–mass spectrometry (GC–MS). Phenylpropanoids and flavonoids were found to be the major potential antioxidants in Jumi based on the pre-column DPPH-HPLC assay. For simultaneous analysis of multi-target components, HPLC quantitative method was constructed by using 11 identified compounds. The results demonstrated that the chemical compositions and contents among 10 batches of Jumi are consistent. 6 phenylpropanoids and 3 flavonoids appeared as the main constituents in Jumi and showed obviously higher contents (>1 mg/g). Especially, the contents of two flavanones, eriodictyol-7-O-β- d -glucuronide and eriodictyol-7-O-β- d -glucoside are prominent in Jumi. The principal component analysis (PCA) suggests obvious differences between Jumi and other cultivars buds. Eriodictyol-7-O-β- d -glucuronide, isochlorogenic acid A (3, 5-diCQA), chlorogenic acid (3-CQA), and isochlorogenic acid C (4, 5-diCQA) can be used as the specific target components to distinguish Jumi from other buds.

Various DNA-modulated photosensitization schemes have been reported for various applications, but DNAzyme has not yet been included. Here, we found the DNAzyme with metal ion as cofactor could also be efficient in modulation of photosensitization process. The UO 2 2 + -specific DNAzyme can switch between double strand DNA (dsDNA) and single strand DNA (ssDNA) upon UO 2 2 + cleavage, which can regulate the photosensitization process of SYBR Green I. Coupling with photosensitization-induced chromogenic reaction (TMB oxidation), a simple colorimetric sensor for UO 2 2 + was developed accordingly. To increase the visual resolution of the proposed assay, a background color was supplied. Compared with the previous DNAzyme-based UO 2 2 + sensors, the proposed assay featured label-free and simple. Besides, the tolerance for high salinity of this assay is appealing. The proposed assay offered a detection limit of 0.08 μg/L with UV−vis detection and 0.5 μg/L with the naked eye. With the proposed colorimetric assay, UO 2 2 + levels in the range of 0.7–1.2 μg/L (2.9–5.0 nM) were identified in high salinity seawater samples, with spike-recoveries ranging from 93% to 104%.

Benzothiazole (BT) and its derivates are commonly used as vulcanization accelerators in rubber production. Information on the occurrence of BTs in road dust (RD) and on human exposure to these compounds is very limited. BT and its six derivates in tire wear particles (TWPs) and RD were determined in this study. Samples were extracted using solid-liquid extraction, purified by a HLB SPE column, and determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). All seven BTs were found in 17 TWPs samples from different tire brands. The mass fractions of all seven BTs (∑BTs) in TWPs ranged from 46.93 to 215 μg/g with an average concentration of 99.32 μg/g. Benzothiazole and 2-hydroxybenzothiazole (2-OH-BT) were the two major compounds, accounting for 56%-89% of the total. The seven BTs were also found in all 36 sets of RD samples (each set included one sample of TSP (particles < 75 μm in diameter), PM10 (particles < 10 μm in diameter) and PM2.5 (particles < 2.5 μm in diameter)) fractions of RD. The median ∑BTs concentration was highest in PM2.5 (26.62 μg/g), followed by PM10 (22.03 μg/g), and TSP (0.68 μg/g). Of the seven BTs, BT, 2-aminobenzothiazole (2-NH2-BT), 2-mercaptobenzothiazole (MBT), and 2-(methylthio)benzothiazole (MTBT) were distributed in PM2.5 and 2-OH-BT was distributed in PM2.5-10 of RD. Based on the mass fractions of BTs in the TSP, PM10, and PM2.5 fractions of RD, human exposure via ingestion, inhalation and dermal absorption were evaluated. Ingestion was found to be the main exposure pathway in humans, and daily intake of BTs in PM2.5 was highest, followed by PM10 and TSP, respectively. Children may suffer more health risks than adults when exposed to RD.

Detection of cyanide (CN-) ion is of essential importance due to its high toxicity to human life. Herein, we developed a gold nanoclusters (AuNCs)-peroxyoxalate chemiluminescence (CL) system for ultrasensitive detection of CN- in environmental water samples. Bis (2,4,5-trichloro-6-carbopentoxyphenyl) oxalate (CPPO)-hydrogen peroxide (H2O2) CL reaction was utilized to produce high energy intermediates, namely energy donors, and AuNCs served as the acceptors to harvest the energy via CL resonance energy transfer (CRET) process. Besides, it was demonstrated that AuNCs also could act as a catalyst to enhance the generation of the high energy intermediate; and the AuNCs also had an aggregation induced emission (AIE) effect in the organic solvent that was used in CPPO-based CL system. In the presence of CN-, AuNCs can be etched by CN- due to the Elsner complexation reaction between CN- and AuNCs, and thus both of the quantum yield and catalytic activity decreased remarkably. As a result, significant quenching of CPPO-AuNCs CL intensity was observed. The CL intensity decreased linearly in the concentration range of 2.5-125 μg/L CN-, and the detection limit was calculated to be 0.55 μg/L, 10-fold lower than that obtained by the fluorescent sensing of AuNCs. The relative standard deviation was 4.3% for seven parallel measurements of 100 μg/L CN-. It also exhibited high selectivity and favorable anti-interference capability. The sensing system was used for detection of CN- in five standard water samples, and the analytical results were in good agreement with the certified values. Overall, the simple and sensitive CL sensing platform offers a promising tool for convenient detection of CN- in environmental water samples.

Thallium (Tl) is an extremely toxic heavy metal and exists in very low concentrations in the environment, but its sensing is largely underexplored as compared to its neighboring elements in the periodic table (especially mercury and lead). In this work, we developed a ratiometric phosphorescent nanoprobe for thallium detection based on Mn-doped ZnSe quantum dots (QDs) and water-soluble carbon dots (C-dots). Upon excitation with 360 nm, Mn-doped ZnSe QDs and C-dots can emit long-lived and spectrally resolved phosphorescence at 580 and 440 nm, respectively. In the presence of thallium, the phosphorescence emission from Mn-doped ZnSe QDs could be selectively quenched, while that from C-dots retained unchanged. Therefore, a ratiometric phosphorescent probe was thus developed, which can eliminate the potential influence from both background fluorescence and other analyte-independent external environment factors. Several other heavy metal ions caused interferences to thallium detection but could be efficiently masked with EDTA. The proposed method offered a detection limit of 1 μg/L, which is among the most sensitive probes ever reported. Successful application of this method for thallium detection in biological serum as well as in environmental water and soil samples was demonstrated.

H2 O2 and horseradish peroxidase (HRP) are commonly used together in bioassays. HRP is required to accelerate the reaction between a chromogenic substrate (e.g., 3,3',5,5'-tetramethylbenzidine, TMB) and H2 O2 , and thus amplifies the signal. Herein, molecular oxygen for enzyme-free and H2 O2 -free oxidation is explored, still using the same colorimetric reaction. Restricted by spin selection rules, the ground-state triplet oxygen needs to be converted to the singlet state to oxidize TMB. Phloxine B (PB) is used as the photosensitizer because of its excellent performance and safety. Under green light irradiation, each PB has a turnover of approximately 51 TMB molecules in 20 min, making PB a "molecular enzyme mimic" for signal amplification. With its small size, multiple PB molecules are loaded on a graphene oxide nanosheet to design a modified enzyme-linked immunosorbance (ELISA) assay (termed photosensitization immunosorbent assay, PISA), improving the 1:1 enzyme/target ratio to n:1. PISA is more sensitive for carcinoembryonic antigen than a commercial ELISA kit, and successfully measures the antigen in the serum of multiple cancer patients. This simple and green method of oxidation coupled with the small size of the photosensitizer and graphene oxide may enable many other applications in biosensor development, smart materials, and energy harvesting.

Chimonanthus Lindl. has seven family members with Ch. praecox blooming in winter and others in autumn. The plants are widely used in landscaping, fragrance industry, as well as production of medicinal material because of their flower fragrance. Both Chimonanthus flowers and leaves contain abundant secondary metabolites. But it is unclear whether the flowers from different species have distinct ingredients and antioxidant activity. To address the question, we evaluated the main compositions of the flowers from five Chimonanthus species and analyzed the antioxidant activity of the compositions. The results indicated that flavonoids and coumarins are the two major types of substances with antioxidant capacity in Chimonanthus flowers. Totally nine antioxidative compounds, including scopolin and scopoletin, were identified based on the high performance liquid chromatography-photo diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD/ESI–MS). All the antioxidant compounds were confirmed by pre-column 2, 2-diphenyl-1- picryhydrazyl (DPPH) assay. Rutin (highest in content), isoquercitrin and quercetin appeared stronger scavenging DPPH radical ability than the other five compounds, mainly due to their ortho-dihydroxyl groups. Among the five Chimonanthus species, Ch. praecox flower is most abundant in secondary metabolites and shows most potent antioxidant activity. The other four flowers contain the same types of ingredients with Ch. praecox, but exhibit lower antioxidant activity. The results obtained from this comprehensive analysis provide a theoretical basis for the utilization of the plant resources of Chimonanthus genus.

Efficient thermal dissipation has become a critical factor limiting the development of electronic devices. Thermal interface materials (TIMs) connecting the surfaces of heat source and heat sink, are important to guarantee stable and sufficient heat dissipation from heat source to heat sink. Carbon fibers (CFs) are widely used as the reinforcing fillers to enhance the thermal conductivities of polymer-based composites because of their extremely high thermal conductivities in axial direction. However, conventional methods of CFs cannot take full advantage of their high thermal conductivities because heat conductive channels in composite are not efficiently built due to the greatly larger viscosity of composite caused by CFs under high filler concentration. To solve this problem, we report a magnetic field-based and viscosity-independent method to fabricate the nickel-coated carbon fibers (NICFs) filled polydimethylsiloxane (PDMS) composites with the highspeed through-plane heat conductive channels under high filler concentration. The NICFs-composite shows 69 times enhanced through-plane thermal conductivity (10.50 W/(m∙K)) compared to that of pure PDMS (0.15 W/(m∙K)) and low thermal expansion coefficient (CTE) of 55.14 ppm/°C at 51.54 wt%. Compared to commercial TIMs, the NICFs-composites exhibits better thermal performance, demonstrating potential application prospects in electronic devices cooling area.

The assay of biomarker proteins is of critical importance for disease diagnosis. In this work, we have designed a cascaded strand displacement reaction system for detection of low abundant biomarker protein in serum samples. The proposed binding-induced strand displacement conversion system, first converts a protein recognition event into the output of the DNA (cDNA) catalyst, and then the output cDNA catalytically load the reporter DNAzyme onto magnetic beads based on catalyzed hairpin assembly (CHA) reaction. The high density of the hairpin DNA on a magnetic bead surface results in an over 20-fold improvement in the reaction efficiency of CHA, compared with conventional CHA. In addition, the magnetic beads are able to efficiently separate the serum sample matrix that could remarkably affect the DNAzyme-catalyzed chemiluminescent (CL) reaction. This type of magnetic biosensor allows for the detection of 0.5 pM target protein in serum samples, whereas when using homogenous CHA biosensors, the CL signal for 2 nM PDGF-BB is seriously inhibited by the serum matrix. Since the sensing system integrates the protein recognition, signaling, signal amplification and matrix separation functions, it is promising for the assay of proteins in biological samples.

MIL-100(Fe) was the first time used in a continuous flow system. Under the continuous flow, higher catalytic efficiency was achieved than in the batch system, which is attributable to a lower inhibition by products. This method provides a new approach to MOFs applied as heterogeneous catalysts for the synthesis of fine chemicals.

Due to the various functional oxygen-containing groups, graphene oxide (GO) has been frequently explored as sorbent for various metal ions and organic pollutants. However, the adsorption capacity of solely GO is limited. Therefore, compositing GO with other adsorbents to improve the adsorption capacity is often required. On the other hand, the oxygen functional groups enable GO for exciton generation, which has been harvested for photosensitized generation of reactive oxygen species (ROS). Photosensitization has been explored for advanced pollutant degradation. Here, the adsorption and photosensitization effect of GO was synergized for improving the pollutant removal performance. Hydroquinone (HQ) was taken as the model pollutant for the illustration of the synergic effect. GO could adsorb HQ, possibly due to π–π stacking and hydrogen-bonding interactions between GO and HQ. In the presence of white light irradiation (LED), the removal efficiency for HQ was greatly improved. Spectroscopic study indicated the improved removal efficiency could be ascribed to light irradiation-induced HQ oxidation. Further study showed that violet LEDs exhibited higher oxidation efficiency than white, blue, green, yellow, and red LEDs, since violet LEDs possess the largest spectra overlap with the absorption of GO. Via scavenger studies, the exact oxidants were identified as ˙OH, 1O2, and ˙O2−, which are generated from GO photosensitization. Another intriguing feature is that GO can be recycled in several runs of adsorption/photosensitization of pollutants. Moreover, the synergic adsorption/photosensitization feature of GO can be extended to remove a broad band of phenolic pollutants, demonstrating the universality of such strategy for improved pollutant removal.

The article describes a bienzyme visual system for aptamer-based assay of Hg(II) at nanomolar levels. The detection scheme is based on the finding that Hg(II) ions captured by aptamer-functionalized magnetic beads are capable of inhibiting the enzymatic activity of uricase and thus affect the formation of H2O2 and the blue product, i.e., oxidized tetramethylbenzidine. This strategy allows for a visual detection of Hg(II) at nanomolar levels without additional amplification procedure. Measuring the absorbance at 650 nm, the logarithmic calibration plot is linear in the concentration range of 0.5–50 nM and the limit of detection (LOD) is 0.15 nM. This is as low as the LOD obtained by atomic fluorescence spectrometry (AFS). The ions K+, Mg2+, Na+, Ca2+, Cu2+, Zn2+, Fe3+, Al3+, Co2+, AsO2 −, Ni2+, Cd2+ and Pb2+ do not have a significant effect on color formation. The method was applied to the analysis of (spiked) river water, lake water, mineral water, tap water and certified reference water samples, and the results agreed well with those obtained by AFS or certified values, with recoveries ranging from 97% to 109%. The relative standard deviation for five parallel detections at a 10 nM Hg(II) level is 5.2%.

Scope Large-leaf yellow tea (YT) exhibits interesting beneficial metabolic effects in previous studies. Here, the authors elucidated the actions of YT on thermogenesis, energy metabolism, and adipocyte metabolic conversion. Methods and results Five-week-old male C57BL/6 mice are fed low-fat diet, high-fat diet (HFD), and HFD supplemented with 0.5% or 2.5% YT. After treatment for 10 or 14 weeks, YT enhances energy expenditure, O2 consumption and CO2 production. YT strongly boosts thermogenic program in brown adipose tissue (BAT) and subcutaneous adipose tissue (SAT), while only weakly in epididymal adipose tissue (EAT). These are accompanied by higher body temperature, increased mitochondrial copy numbers, and upregulation of thermogenic genes (Ucp1, Pgc1α, etc.) and proteins. The classic brown adipocyte markers (Eva1, Zic1) are induced only in BAT, while beige adipocyte markers (Tbx1, Tmem26) are boosted only in SAT. Furthermore, subcutaneous-originated preadipocytes are induced by YT in vitro to differentiate to brown-like adipocytes - a browning effect. Conclusion Dietary YT induces adaptive thermogenesis through increasing mitochondrial biogenesis in EAT, inducing beigeing in SAT and enhancing browning in the BAT.

In this work, we reported a photocatalytic biosensor for visual detection of superoxide dismutase (SOD) based on Pt-doped graphite phase carbon nitride (g-C3N4). Upon illumination by a violet light-emitting diode (LED), Pt-doped g-C3N4 absorbed the light energy and catalytically produced O2− which further oxidized the dyes into a colorless end product. In the presence of SOD, it can specifically catalyze O2− into oxygen and hydrogen peroxide, leading to a reduced photooxidation and a visual color display. After screening a series of dyes, the azo dye amaranth (AM) was proven to be the best indicator for O2− since the azo bond is active and easily oxidized by O2−, resulting in a low background. Such a simple photocatalytic sensor allows visual detection of SOD at a nM level without the need of any sophisticated instrument; using spectrometry, the linear response for SOD detection ranges from 1.5 to 4500 nM with a limit of detection (LOD, 3σ) down to 0.3 nM. The sensor was also successfully applied for label-free and wash-free detection of SOD in human serum samples with a satisfactory recovery.

We cloned a new gene from the amidase signature (AS) family, designatedam, from the marine actinomyceteSalinispora arenicolaCNS-205. As indicated by bioinformatics analysis and site-directed mutagenesis, the AM protein belonged to the AS family. AM was expressed, purified, and characterised inEscherichia coliBL21 (DE3), and the AM molecular mass was determined to be 51 kDa. The optimal temperature and pH were 40 °C and pH 8.0, respectively. AM exhibited a wide substrate spectrum and showed amidase, aryl acylamidase, and acyl transferase activities. AM had high activity towards aromatic and aliphatic amides. The AM substrate specificity for anilides was very narrow; only propanil could be used as an effective substrate. The extensive substrate range of AM indicates it may have broad potential applications in biosynthetic processes and biodegradation.

Catalyzed hairpin assembly (CHA) is an important DNA engineering tool for a variety of applications such as DNA nanotechnology and biosensing. Here we report a hairpin-type of both-end-blocked DNAzyme to improve the signal-to-background ratio during the CHA process. In the design, the DNAzyme activity can be blocked efficiently via locking both ends of the G-rich DNAzyme sequence in the loop and stem (blocking efficiency = 96%) and can be easily recovered during the CHA process (activation efficiency = 94%). The both-end-blocked DNAzyme is by far the most sensitive optical detection mode for monitoring the CHA process that can be used for determination of 0.05 fmol miRNA-21. The fabricated CHA-DNAzyme sensing system was also able to discriminate miRNA-21 from single-/three-base mismatch miRNA-21. The feasibility of real application was also tested via detection of miRNA-21 levels in tumor cell samples. Therefore, the sensing system with the advantages of convenience, high sensitivity, and selectivity is an appealing strategy for miRNA detection.

An on-line molecularly imprinted solid-phase extraction (MISPE) method was developed for the capillary electrophoresis (CE) detection of bisphenol A (BPA). Analyte extraction was achieved by using an in-column MISPE concentrator, which was prepared by coating the molecularly imprinted polymer (MIP) material directly in the separation capillary. The key parameters influencing the extraction efficiency, including the sample pH, extraction time, desorption solvent, and the injection duration of the desorption solution, were investigated. The combination of MISPE with CE produced a linear relationship between the CE peak areas versus the BPA concentration in the range from 3 to 300 ng mL − 1 with a limit-of-detection (LOD) as low as 0.8 ng mL − 1 . The LOD of MISPE-CE is over 100-fold lower than that of direct CE determination. The MISPE-CE method was used for the analysis of four BPA-spiked samples: tap water, river water, a beverage, and urine, with recoveries in the range of 87.2–108.3%. The MISPE-CE method features the advantages of on-line extraction, ease of atomization, and low sample consumption.

In this study, an efficient sample pretreatment method, salt-assisted graphene oxide dispersive solid phase microextraction (SA-GO-DSPME), was established for extraction of malachite green (MG) and crystal violet (CV). The dispersive graphene oxide was found to be easily aggregated and completely centrifuged in the presence of NaCl. The adsorption kinetic of SA-GO-DSPME was shown to be quite fast (equilibrium time = 5 min). Key parameters that influenced extraction efficiency including sample pH, the eluent type, GO amount, extraction time, NaCl concentration and centrifuging time were investigated. Coupled with SA-GO-DSPME, high-performance liquid chromatography (HPLC) could be used for sensitive detection of MG and CV with detection limits down to 1.7 and 0.3 ng mL−1 for MG and CV, respectively. The relative standard deviations for extraction reproducibility (n = 5) were 1.8 % for MG and 3.8 % for CV. The proposed method has been successfully applied for detection of MG and CV in real water samples, and the recoveries ranged from 89.7 to 116.4 %. This simple and fast extraction method may provide a promising alternative for extraction of trace amount of MG and CV in complicated samples.

In recent years, the interactions between baculoviruses and their insect hosts have become a research focus because baculoviruses can suppress the development and manipulate the behavior of insects. Many studies reported that nucleopolyhedrovirus (NPV) infection might disrupt the hormone balance in insects, but the effect of NPV infection on the development and expression of hormone-related genes in larvae of Helicoverpa armigera Boddie (Lepidoptera: Noctuidae) remains unclear. In this study, the mortality, development time, and pupal weight of H. armigera were recorded after 4th and 5th instars had been treated per os with different concentrations of Helicoverpa armigera single NPV (HaSNPV). Results showed that mortality increased and development time was prolonged to different degrees along with increasing concentrations of HaSNPV. The pupal weight did not differ between the HaSNPV-infected and control insects when 4th instars were infected but was significantly reduced when 5th instars were in...

Starch/poly(vinyl alcohol) (PVA) blend films were prepared from the aqueous solutions containing starch, PVA and magnesium chloride hexahydrate (MgCl2.6H2O). The interaction between MgCl2.6H2O and starch/PVA was studied by Fourier transform infrared spectroscopy. The plasticising effect of MgCl2.6H2O on starch/PVA film was studied by scanning electron microscopy (SEM), X-ray diffraction, thermogravimetric analysis, dynamic mechanical analysis and tensile testing respectively. The water content of starch/PVA films increased with the content of MgCl2.6H2O. The absorbed water can act as the plasticiser for starch/PVA film. The crystals of starch and PVA were destroyed, and the crystallinity of starch/PVA film decreased with the plasticising effect of MgCl2.6H2O and water. SEM micrographs showed that the compatibility between starch and PVA improved with the addition of MgCl2.6H2O. The toughness of starch/PVA film increased with the content of MgCl2.6H2O.

This work describes a magnetic Fe3O4/graphene oxide (GO)-based solid-phase extraction (MSPE) technique for high performance liquid chromatography (HPLC) detection of malachite green (MG) and crystal violet (CV) in environmental water samples. Fe3O4/ GO magnetic nanoparticles were synthesised by a chemical co-precipitation method and characterised by scanning electron micrograph, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and surface area analyser. The prepared Fe3O4/GO magnetic nanoparticles were used as the adsorbents of MSPE for MG and CV. By coupling with HPLC, a sensitive and cost-effective method for simultaneous determination of MG and CV was developed. The important parameters including the amount of Fe3O4/GO, pH of the sample solution, extraction time, salt effect, the type and volume of desorption solvent were investigated in detail. Under optimised conditions, the calibration curves were linear in the concentration range of 0.5–200 μg L−1, and the limits of detection were 0.091 and 0.12 μg L−1 for MG and CV, respectively. Finally, the established MSPE-HPLC method was successfully applied to determine MG and CV in environmental water samples with the recoveries ranging from 91.5% to116.7%.

A screen-printed carbon nanotube (CNTs) based disposable third generation biosensor for hydrogen peroxide (H2O2) was constructed by mixing CNTs with a cellulose acetate binder on an epoxy substrate. The surface was covered with a layer consisting of horseradish peroxidase (HRP) crosslinked to bovine serum albumin with glutaraldehyde. The CNTs acted as both the electrode material and charge promoter to facilitate the direct electron transfer between immobilized HRP and the modified electrode. At a working potential of −300 mV (vs. Ag/AgCl), the biosensor displays an excellent electrocatalytic response to the reduction of H2O2 without the aid of a mediator. It has a fast (3 s) amperometric response and a linear calibration in the concentration range 0.005–0.1 mmol L−1, with a 0.85 μM detection limit (at an S/N of 3). The biosensor can be easily produced, is stable and reproducible.

Coptis chinensisis commonly used in traditional Chinese medicine. The study investigated metabolic interaction of the active constituents (berberine, coptisine, palmatine, and jatrorrhizine) ofCoptis chinensisin human liver microsomes. After incubation of the four constituents ofCoptis chinensisin HLMs, the metabolism of the four constituents was observed by HPLC. Thein vitroinhibition experiment between the active constituents was conducted, and IC50value was estimated. Coptisine exhibited inhibitions against the formation of the two metabolites of berberine with IC50values of 6.5 and 8.3 μM, respectively. Palmatine and jatrorrhizine showed the weaker inhibitory effect on the formation of the metabolites of berberine. Berberine showed a weak inhibitory effect on the production of coptisine metabolite with an IC50value of 115 μM, and palmatine and jatrorrhizine had little inhibitory effect on the formation of coptisine metabolite. Berberine, coptisine, and jatrorrhizine showed no inhibitory effect on the generation of palmatine metabolite (IC50> 200 μM). The findings suggested that there are different degrees of metabolic interaction between the four components. Coptisine showed the strongest inhibition toward berberine metabolism.

We report here the newly discovered photocatalytic activity of the dsDNA-SYBR Green I (SG) complex, which can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) under light irradiation corresponding to the excitation of the dsDNA-SG complex. The most appealing feature of the photocatalytic system here is that it can be obtained using random DNA sequences that can form a duplex. Considering the universality of the photooxidase, a label-free and universal platform was proposed for highly sensitive visual bioassays.

In this article, we report the addition of graphene (Gr) to negative active materials (NAM) of lead-acid batteries (LABs) for sulfation suppression and cycle-life extension. Our experimental results show that with an addition of only a fraction of a percent of Gr, the partial state of charge (PSoC) cycle life is significantly improved by more than 140% from 7078 to 17157 cycles. The particle size on a charged Pb-graphene (PbG) plate after the PSoC test is also found to be reduced by around 25% when compare with a Pb plate. Charge and discharge densities measurements from the cyclic voltammetry (CV) test show an enhancement with the addition of Gr, indicating an improvement in the reversibility reaction of PbSO4. An electrochemical model, which takes into account of reduced interfacial resistance, improved charge transfer and enhanced electroactive surface area, is proposed to elucidate the role of Gr throughout the course of a PSoC cycle test. It is demonstrated that experimental results are aligned with our proposed model with enhanced cycle life performance, where PbG plate maintains a higher electroactive surface area for adsorption and desorption of Pb2+ ions at the interface between active material and electrolyte occurs in parallel to reduced charge transfer.

G-quadruplex DNAzymes that exhibited peroxidase-like activity have been shown to be appealing reporters for amplified readout of biosensing events simply by their formation or dissociation in the presence of analytes. For low background signaling, the efficient preblock of DNAzymes is critically important. Herein, we report a both-end blocked DNAzyme beacon strategy for chemiluminescent biosensing. The catalytic activity of peroxidase-mimicking DNAzyme can be inactivated fully by fixing both ends of the DNAzyme sequence, and easily recovered via a strand displace reaction between the miRNA and the block DNA. The efficient block and recovery of DNAzymes provide the both-end blocked beacon the highest signal-to-background ratio (over 25) among the reported DNAzymes for amplification-free detection of miRNA. As a result, the beacon allowed detection of subpicomolar miRNA without any labeling and amplification procedures, which is about 40-fold more sensitive than the traditional hairpin fluorescence beacon. Also, it exhibited excellent discrimination ability that can distinguish single-base mismatch miRNA. The simplicity, high sensitivity, and selectivity provided by the beacon make it a promising alternative tool for nucleic acid detection.