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Mammalian Müller glia (MG) possess limited regenerative capacities. However, the intrinsic capacity of mammalian MG to transdifferentiate to generate mature neurons without transgenic manipulations remains speculative. Here we show that MAP4K4, MAP4K6 and MAP4K7, which are conserved Misshapen subfamily of ste20 kinases homologs, repress YAP activity in mammalian MG and therefore restrict their ability to be reprogrammed. However, by treating with a small molecule inhibitor of MAP4K4/6/7, mouse MG regain their ability to proliferate and enter into a retinal progenitor cell (RPC)-like state after NMDA-induced retinal damage; such plasticity was lost in YAP knockout MG. Moreover, spontaneous trans-differentiation of MG into retinal neurons expressing both amacrine and retinal ganglion cell (RGC) markers occurs after inhibitor withdrawal. Taken together, these findings suggest that MAP4Ks block the reprogramming capacity of MG in a YAP-dependent manner in adult mammals, which provides a novel avenue for the pharmaceutical induction of retinal regenerationin vivo.

A simple and low-cost fluorescence aptasensor was developed for rapid and sensitive signal amplification detection of T-2 mycotoxin (T-2). Dual-terminal-fluorescein amidite (FAM)–labeled aptamer (D-aptamer) acted as a recognition element and signal indicator. The metal organic frameworks (MOFs) of N, N′-bis(2-hydroxyethyl)dithiooxamidato copper (II) (H2dtoaCu) were as the quencher. The D-aptamer was initially adsorbed to the surface of H2dtoaCu, leading to efficient quenching of the aptasensor. Upon addition of T-2, the D-aptamer underwent a conformation change to form the T-2/T-2 aptamer complex, which induced the signaling probe to be released from the H2dtoaCu surface. Thus, the fluorescence intensity (FL) of the D-aptamer was recovered. Versus the single-terminal-FAM-labeled aptamer (S-aptamer), the D-aptamer showed a lower detection limit of 0.39 ng/mL. The aptasensor was also successfully applied to detect T-2 in corn and wheat samples with good recoveries.

A portable instrument-free detection method for lipopolysaccharide (LPS) analysis was developed based on dual-emission ratiometric fluorescence sensing system. Herein, red-emitting Au nanoclusters (Au NCs) were as reference probe, while blue-emitting fluorescent silica quantum dots (Si QDs) were as response probe. Additionally, the aptamer of LPS was covalently grafted to the surface of Si QDs in order to specific recognize the LPS. According to the changes of fluorescence intensityratio (FL ratio, I

An aptamer-labelled fluorescent nanoprobe-integrated shell-isolated nanoparticle-enhanced fluorescence spectroscopy (SHINEFs) had been proposed for selective and sensitive detection of Tc. In the s...

Hydrophilic poly(glyceryl monomethacrylate) (PGMMA) brush-functional nanoparticles were prepared via macromolecular chain-transfer-agent-adjusted reversible addition–fragmentation chain-transfer pr...

A weak CL emission was initiated by peroxynitrous acid (PA) produced by the interaction of nitrite with hydrogen peroxide in sulphuric acid solution. In the presence of nitrogen doped carbon dots (NCDs), the CL intensity was enhanced significantly. The CL mechanism of the NCDs-PA system was studied using the CL spectrum, FL spectrum and the effect of radical scavengers. The NCDs-PA CL system was developed for the determination of 2-naphthol (2-NAP) based on its inhibition effect. The reduced CL intensity was proportional to the concentration of 2-NAP in the range from 0.3 to 20.0 μM and the detection limit was 48.0 nM. This method had been successfully applied to determine 2-NAP in environmental water samples with recoveries of 99.5-102.8%.

The carbon dots doped with chlorine and phosphorus (CDs-Cl,P) were used as chemiluminescence (CL) reagent for the sensitive detection of copper ions (Cu

Lipopolysaccharide (LPS), as the major component of the outer membrane of Gram-negative bacteria, can trigger a variety of biological effects such as sepsis, septic shock, and even multiorgan failure. Herein, we developed a near-infrared-fluorescent probe for fluorescent turn-on analysis of LPS based on plasmon-enhanced fluorescence (PEF). Gold nanorods (Au NRs) modified polyethylene glycol (PEG) was used as PEF materials. Au NRs were prepared with different longitudinal surface plasmon resonance (LSPR), and their fluorescence enhancement was investigated. Three kinds of molecular weights (1000, 5000, and 10000) of polyethylene glycol (PEG) were employed to control the distance between the Au NRs and the fluorescence substances of cyanine 7 (Cy7). Experimental analysis showed that the enhancement was related to the spectral overlap between the plasmon resonance of Au NRs and the extinction/emission of fluorophore. The three-dimensional finite-difference time-domain (3D-FDTD) simulation further revealed that the enhancement was caused by local electric field enhancement. Furthermore, the probe was used for the ultrasensitive analysis of LPS with a detection limit of 3.85 ng/mL and could quickly distinguish the Gram-negative bacterium-Escherichia coli (E. coli) (with LPS in the membrane) from Gram-positive bacterium-Staphylococcus aureus (S. aureus) (without LPS), as well as quantitative determination of E. coli with a detection limit of 1.0 × 106 cfu/mL. These results suggested that the prepared probe has great potential for biomedical diagnosis and selective detection of LPS from different bacterial strains.

A simple and low-cost fluorescence aptasensor was developed for rapid and sensitive signal amplification detection of T-2 mycotoxin (T-2). Dual-terminal-fluorescein amidite (FAM)-labeled aptamer (D-aptamer) acted as a recognition element and signal indicator. The metal organic frameworks (MOFs) of N, N'-bis(2-hydroxyethyl)dithiooxamidato copper (II) (H

MoSDT1, a rice blast fungus transcription factor, is as an inducer to activate defense response through mainly mediating phosphorylated proteins in rice. Pathogen effector proteins play a dual role in infecting the host or triggering a defense response. Our previous research found a Magnaporthe oryzae effector, MoSDT1, which could activate the rice defense response when it was overexpressed in rice. However, we still know little about the mechanisms on how MoSDT1 in vivo or in vitro influences the resistance ability of rice. Our results showed that decreased ROS and increased lignin contents appeared along with significant upregulation of defense-related genes, raffinose synthesis gene, and phenylalanine ammonialyase gene. Moreover, we revealed that the contents of lignin were increased, which was in accordance with the upregulation of its precursor phenylalanine gene despite the fact that the glutamate-/thiamine-responsive genes were inhibited in MoSDT1 transgenic rice, and these indicated that MoSDT1 triggered the defense system of rice in vivo. Interestingly, in vitro studies, we further found that MoSDT1 induced the defense system by ROS synthesis, callose deposition, PR gene expression and SA/JA synthesis/signal genes using the purified prokaryotic expression system in rice plants. In addition, this defense response was confirmed to be activated by the zinc finger domain of MoSDT1 via prokaryotic expression of MoSDT1 truncated mutants in rice plants. To elucidate the regulative effects of MoSDT1 on protein phosphorylation in rice, phosphoproteome analysis was performed in both MoSDT1-transgenic and wild type rice. We found that MoSDT1 specifically up-regulated the expression levels of a few phosphorylated proteins, which were involved in multiple functions, such as biotic/abiotic stress and growth. In addition, the motifs in these specific proteins ranked the top among the top-five conserved motifs in the MoSDT1-transgenic rice. MoSDT1 played a crucial role in enhancing rice resistance by modulating several genes and signaling pathways.

Paper has unique advantages over other materials, including low cost, flexibility, porosity, and self-driven liquid pumping, thus making it widely used in various fields in biology, chemistry, physics and materials science. Recently, many multifunctional and highly integrated membrane-based devices have been achieved with the rapid development of membrane-building materials such as paper and pseudo-paper. Therefore, the rigid boundary between paper and other membranes has become blurred; paper can be considered a flexible membrane, and membranes with appropriately flexible or porous structures can also be defined as paper. Paper can manipulate liquids and respond photoelectrically to external objects to be measured, making it suitable for (bio)chemical sensing (chromatographic analysis, electrochemical analysis and wearable sensing). This review focuses on the development of microfluidic devices built with both traditional paper and other flexible membranes, including fabrication, (bio)chemical sensing, microfluidics manipulation and multiple applications.

In recent years, with the development of artificial intelligence technologies, mobile smart terminals, and high-bandwidth wireless internet, the scale of data generated by various data sources has continued to expand. Huge amounts of data contain huge economic value, therefore how to store and process the data efficiently becomes very significant. HDFS (Hadoop Distributed File System) has emerged as a typical representative of data-intensive distributed file systems, and it has features such as high fault tolerance, high throughput, and can be deployed on low-cost hardwares. However, the remote procedure call in HDFS is still not good enough to work better in terms of network throughput and abnormal response. This paper presents an optimization method to improve the performance of HDFS. The proposed method dynamically adjusts the RPC (Remote Procedure Call) configurations between NameNode and DataNodes by sensing the data characters that stored in DataNodes. This method can effectively reduce the processing pressure of the NameNode and reduce the network throughput generated by the information transmission between NameNode and DataNodes. It can also reduce the abnormal response time of the whole system. Finally, the extensive experiments show the effectiveness and efficiency of our proposed method.

Silicon nanocrystals (Si NCs) have received surging interest as a type of quantum dot (QD) due to the availability of silicon in nature, tunable fluorescence emission properties and excellent biocompatibility. More importantly, compared with many group II&ndash, VI and III&ndash, V based QDs, they have low toxicity. Here, thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-functional Si NCs were firstly prepared for thermoresponsive detection of cancer cells. Si NCs were prepared under normal pressure with excellent water solubility. Then folic acid was bonded to the silicon nanocrystals through the reaction of amino and carboxyl groups for specific recognition of cancer cells. The folic-acid-modified silicon crystals (Si NCs-FA) could be modified by a one-pot copolymerization process into PNIPAAm nanospheres during the monomer polymerization process (i.e., Si NCs-FA-PNIPAAm) just by controlling the temperature below the lower critical solution temperature (LCST) and above the LCST. The results showed that the Si-FA-PNIAAm nanospheres exhibited not only reversible temperature-responsive on-off fluorescence properties, but also can be used as temperature indicators in cancer cells.

Silicon nanocrystals (Si NCs) have received surging interest as a type of quantum dot (QD) due to the availability of silicon in nature, tunable fluorescence emission properties and excellent biocompatibility. More importantly, compared with many group II–VI and III–V based QDs, they have low toxicity. Here, thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-functional Si NCs were firstly prepared for thermoresponsive detection of cancer cells. Si NCs were prepared under normal pressure with excellent water solubility. Then folic acid was bonded to the silicon nanocrystals through the reaction of amino and carboxyl groups for specific recognition of cancer cells. The folic-acid-modified silicon crystals (Si NCs-FA) could be modified by a one-pot copolymerization process into PNIPAAm nanospheres during the monomer polymerization process (i.e., Si NCs-FA-PNIPAAm) just by controlling the temperature below the lower critical solution temperature (LCST) and above the LCST. The results showed that the Si-FA-PNIAAm nanospheres exhibited not only reversible temperature-responsive on-off fluorescence properties, but also can be used as temperature indicators in cancer cells.

BackgroundSubclinical hypothyroidism (SCH) brain structure and resting state of functional activity have remained unexplored.PurposeTo investigate gray matter volume (GMV) and regional brain activity with the fractional amplitude of low-frequency fluctuations (fALFF) in subclinical hypothyroidism (SCH) patients before and after treatment.Material and MethodsWe enrolled 54 SCH and 41 age-, sex-, and education-matched controls. GMV and fALFF of SCH were compared with controls and between pre- and post-treatment within SCH group. Correlations of GMV and fALFF in SCH with thyroid function status and mood scales were assessed by multiple linear regression analysis.ResultsCompared to controls, GMV in SCH was significantly decreased in Orbital part of inferior frontal, superior frontal, pre-/postcentral, inferior occipital, and temporal pole gyrus. FALFF values in SCH were significantly increased in right angular, left middle frontal, and left superior frontal gyrus. After treatment, there were no significant changes in GMV and the local brain function compared to pre-treatment, however the GMV and fALFF of the defective brain areas were improved. Additionally, decreased values of fALFF in left middle frontal gyrus were correlated with increased mood scales.ConclusionIn this study we found that patients with SCH, the gray matter volume in some brain areas were significantly reduced, and regional brain activity was significantly increased. After treatment, the corresponding structural and functional deficiencies had a tendency for improvement. These changes may reveal the neurological mechanisms of mood disorder in SCH patients.

In this work, aminophenylboronic acid functionalized mesoporous silica coated CdTe quantum dots (APBA-coated QDs) were synthesized and applied to the selective capture and fluorescent quantification of glycoproteins. The as-prepared APBA-coated QDs, relying on the interaction between APBA and cis-diol containing structures, demonstrated excellent selectivity for the glycoproteins. Their high surface area and APBA-enriched silica matrixes give rise to faster binding kinetics and higher binding capacity for the glycoproteins, which further make them attractive for biomedical/chemical sensing applications. Based on the fluorescent properties of the particles, the as-prepared APBA-coated QDs were successfully applied to the fluorescence quantification of glycoproteins. The present study provides a facile strategy to fabricate functionalized fluorescent materials and is of great significance for isolation and detection of glycoproteins in proteomics.

Blockchain technology is a combination of distributed data storage, peer-to-peer network, consensus mechanism, timestamp technology, encryption algorithm and other computer technologies. It provides a new solution for the secure distributed cloud data storage system. Blockchain can provide a decentralized secure storage architecture that does not require the accumulation of trust, and it can provides new solutions for cloud storage security and can be applied in time-sensitive areas. This paper summarizes the existing blockchain-based systems and applications, and we mainly review the applications of blockchain traceability technology in various fields, the blockchain decentralized applications, and other blockchain applications in data security protection, respectively. This work may bring new opportunities and challenges for the development of various industries in the future.

A pilot-scale study on start-up and stable operation of mainstream partial nitrification-anammox biofilter (PN/AF) system was conducted. The partial nitrification system was controlled based on online pH-dissolved oxygen (DO) linkage control strategy for nitrite oxidizing bacteria (NOB) out-selection. The immobilized anammox system was an upload biofilter reactor where anammox bacteria were immobilized on the volcanic carriers. The results showed that the nitrite accumulation ratio (NAR) was maintained above 90%, and the NO2—N/NH4+-N value was kept at 0.96 ± 0.18 in the effluent of the partial nitrification system; the mean ammonia concentration of the effluent was below 5 mg/L, and total inorganic nitrogen (TIN) removal loading could achieve 0.11 kg/m3·d after the stable operation in the whole system. The results of high-throughout sequencing showed that the NOB (mainly Nitrospira, Nitrotoga) was out of the partial nitrification system after 30-day operation, the relative abundance of which is less than 1% observed from Krona maps, and ammonia oxidizing bacteria (AOB, mainly Nitrosomonas) became the dominant species of nitrobacteria, the 8% of AOB stabilized finally. Dominant anammox bacteria was identified as genus Candidatus Brocadia, and one kind of rare anammox named Asahi BRW_2 was found to be at the downside of the volcanic biofilter reactor. It could be found the online pH-DO linkage control strategy allowed out-selection of NOB from the mainstream SBR system, and realized a stable partial nitrification. In addition, high DO (2.5 ± 0.5 mg/L) condition was found to be favorable for NOB out-selection and the stabilization of nitritation. The anammox bacteria could be well immobilized in volcanic carriers, with an ability of low ammonia resistance. The study was helpful for engineering application of mainstream anammox process.

ObjectiveTo identify risk factors for haemorrhagic transformation in Chinese patients with acute ischaemic stroke treated with recombinant tissue plasminogen activator.MethodsWe searched electronic databases including PubMed, EMBASE, CNKI and WanFang Data for studies reporting risk factors of haemorrhagic transformation after intravenous thrombolysis. Pooled OR, weighted mean difference (WMD) and 95% CI were estimated. Meta-analysis was performed by using Stata V.14.0 software.ResultsA total of 14 studies were included. The results indicated that older age (WMD=3.46, 95% CI 2.26 to 4.66, I2=47), atrial fibrillation (OR 2.66, 95% CI 1.85 to 3.81, I2=28), previous stroke (OR 1.68, 95% CI 1.08 to 2.60, I2=14), previous antiplatelet treatment (OR 1.67, 95% CI 1.17 to 2.38, I2=0), higher National Institute of Health stroke scale scores (OR 1.10, 95% CI 1. 05 to 1.15, I2=36), systolic (WMD=4.75, 95% CI 2.50 to 7.00, I2=42) or diastolic (WMD=2.67, 95% CI 1.08 to 4.26, I2=35) pressure, and serum glucose level (WMD=1.44, 95% CI 0.62 to 2.26, I2=66) were associated with increased risk of post-thrombolysis haemorrhagic transformation.ConclusionThe current meta-analysis identified eight risk factors for post-thrombolysis haemorrhagic transformation in Chinese patients with acute ischaemic stroke. Given the risk of bias, these results should be explained with caution and do not justify withholding intravenous thrombolysis.

Cancer-induced bone pain (CIBP) is considered to be one of the most difficult pain conditions to treat. Morphine, an analgesic drug, is widely used in clinical practice, and long-term use of morphine can lead to drug tolerance. Recent reports have suggested that inhibitors of epidermal growth factor receptor (EGFR) may have analgesic effects in cancer patients suffering from pain. Therefore, we sought to determine whether EGFR signaling was involved in morphine tolerance (MT) in a rat model of cancer-induced bone pain. In this study, Walker 256 mammary gland carcinoma cells were inoculated into the tibias of rats to provoke cancer-induced bone pain. Then, morphine was intrathecally administered twice daily for seven consecutive days to induce drug tolerance. We observed sustained increased in the protein levels of EGFR, p-EGFR, ERK1/2, and p-ERK1/2 during the development of morphine tolerance in rats with cancer-induced bone pain by western blotting. The EGFR level was significantly increased in the MT and CIBP + MT groups, and EGFR was colocalized with markers of microglia and neurons in the spinal cords of rats. Inhibition of EGFR by a small molecule inhibitor markedly attenuated the degree of morphine tolerance and decreased the number of microglia, and the protein levels of EGFR, p-EGFR, ERK1/2, and p-ERK1/2 were also reduced. In summary, our results suggest that the activation of the EGFR signaling pathway in spinal microglia plays an important modulatory role in the development of morphine tolerance and that inhibition of EGFR may provide a new therapeutic option for cancer-induced bone pain.

We report room temperature ferromagnetism in superconducting YBa 2 Cu 3 O 7-δ /Y 2 BaCuO 5 composites prepared by a citric acid complexing-hydrothermal synthesis coupled method. Scanning electron microscopy observation shows the formation of solid and hollow microspheres. These microspheres are composed of many irregular particles with the size of 100–500 nm. A superconducting transition about 93 K is revealed by zero-field-cooling and field-cooling magnetization curves. Electron spin resonance spectra at various temperatures further confirm the superconducting behaviors at low temperatures. X-ray photoelectron spectroscopy and energy dispersive X-ray spectrum indicate the intrinsic nature of the observed ferromagnetism. Post-heating treatment experiments at argon gas and in the air imply that the observed ferromagnetism should be responsible for an interface-induced mechanism.

Insulin-like growth factor (IGF)-1 functions as a neuroprotective hormone and may protect against cognitive impairment, which may occur as a result of sevoflurane exposure. The aim of the present study was to assess the effect of sevoflurane on the production of IGF‑1 and investigate the molecular mechanisms underlying this regulation. The BRL rat hepatocyte cell line and adult mice were exposed to 1 or 2 minimal alveolar concentrations sevoflurane for 4 or 8 h. IGF‑1 and microRNA‑98 levels were quantified using an enzyme‑linked immunosorbent assay, western blotting and reverse transcription‑quantitative polymerase chain reaction analyses. The importance of microRNA‑98 in the regulation of IGF‑1 by sevoflurane was investigated using a microRNA‑98 inhibitor. Sevoflurane treatment reduced IGF‑1 levels and simultaneously upregulated microRNA‑98 expression levelsin rat hepatocytes and adult mice. Inhibition of microRNA‑98 attenuated this effect. Therefore, sevoflurane may reduce the synthesis of IGF‑1 by upregulating microRNA‑98 expression.

A porous composite membrane with P(VDF-HFP) as host and nonwoven as reinforcement has been successfully prepared and reported in this paper. The tensile strength of the composite is very close to that of Celgard 2730 separator in both wet and dry state. The Na+ ionic conductivity of the given gel-type composite membrane (0.82 mS cm−1) absorbed NaClO4 organic liquid electrolyte at room temperature has found to be four times higher than that of the commercial separator saturated with the same electrolyte (0.16 mS cm−1). It has also showed enhanced transference number of Na+ ions and good electrolyte retention even at 110 °C. The electrochemical reversibility for Na4Mn9O8 cathode has been confirmed by cyclic voltammetry by using the aforementioned gel polymer electrolyte (GPE). The porous composite GPE exhibits great application prospect for sodium ion batteries with high energy density.

A facile and efficient one-pot approach for the synthesis of quantum dot (QD)-labeled hydrophilic molecularly imprinted polymer (MIP) nanoparticles for direct optosensing of folic acid (FA) in the undiluted bovine and porcine serums is described. Hydrophilic macromolecular chain transfer agent-mediated reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization was used to implement the molecular imprinting of FA in the presence of CdTe quantum dots (QDs). The resulting FA-imprinted polymer nanoparticles with surface-grafted hydrophilic poly(glyceryl monomethacrylate) brushes and QDs labeling not only showed outstanding specific molecular recognition toward FA in biological samples, but also exhibited good photostability, rapid binding kinetics, and obvious template binding-induced fluorescence quenching. These characteristics make them a useful fluorescent chemosensor for directly and selectively optosensing FA in the undiluted bovine and porcine serums, with its limit of detection being 0.025μM and average recoveries ranging from 98% to 102%, even in the presence of several interfering compounds. This advanced fluorescent MIP chemosensor is highly promising for rapid quantification of FA in such applications as clinical diagnostics and food analysis.

The rapid development of and the large market for medical diagnostics necessitate point-of-care testing (POCT) with superior sensitivity, miniaturization, multiple functionalities and high integration. Thus, flexible substrates with complex structures that provide multiple functions are in demand. Herein, we present multistructured pseudo-papers (MSPs) as a platform for building flexible microfluidics. Flexible and freestanding MSPs are generated by the self-assembly of colloidal silica crystals or core-shell copolymer elastic colloidal crystals on microcavity PDMS molds to form photonic crystals (PCs). Nitrocellulose (NC) multistructured pseudo-papers (NC MSPs) were obtained by etching SiO2 PCs after NC precursor infiltration, while elastic copolymer (EC) multistructured pseudo-papers (EC MSPs) were directly peeled off the mold; both types of freestanding MSPs have ordered micropillars and nanocrystal structures and presented unique properties such as pumpless liquid transport and fluorescence and chemiluminescence (CL) enhancement. MSPs with designed patterns were fabricated by patterned PDMS molds, and complicated microfluidic chips were used to generate MSPs by utilizing these patterns as liquid channels. The MSPs were used for fabricating microfluidic sensors for human cardiac marker and cancer marker sensing; the features of these bioinspired MSPs indicate their potential for sensitive sensing, which will enable them to find broader applications in many fields.

The ultra-weak chemiluminescence (CL) of Fenton system (Fe2+–H2O2) could be enhanced by phosphorus and chlorine co-doped carbon dots (PClCDs) or eosinY (EY), respectively. Surprisingly, the CL intensity of Fenton system was further improved in the co-presence of PClCDs and EY. The synergistic enhancing effect of PClCDs and EY on the CL emission of Fenton reaction provided a more strong and efficient CL system. It was found that methionine (Met) could effectively diminish the CL intensity of PClCDs-EY-Fenton system. Under the optimium conditions, a linear dynamic range of 0.1–10.0 μM Met concentrations was obtained, with limit of detection (LOD) and quantification (LOQ) of 0.03 μM and 0.1 μM, respectively. The practical application of the presented CL system was demonstrated for detection of Met in food additive and feed additive samples. The mechanism of CL emission was described.

Efficient one-pot synthesis of hydrophilic and fluorescent molecularly imprinted polymer (MIP) nanoparticles and their application as optical chemosensor for direct drug quantification in real, undiluted biological samples are described. The general principle was demonstrated by preparing tetracycline (Tc, a broad-spectrum antibiotic)-imprinted fluorescent polymer nanoparticles bearing hydrophilic polymer brushes via poly(2-hydroxyethyl methacrylate) (PHEMA) macromolecular chain transfer agent-mediated reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization in the presence of a fluorescent monomer. The introduction of hydrophilic PHEMA brushes and fluorescence labeling onto/into the MIP nanoparticles proved to not only significantly improve their surface hydrophilicity and lead to their obvious specific binding and high selectivity toward Tc in the undiluted bovine serum, but also impart them with strong fluorescent properties. In particular, significant fluorescence quenching was observed upon their binding with Tc in such complex biological milieu, which makes these Tc-MIP nanoparticles useful optical chemosensor with a detection limit of 0.26 μM. Furthermore, such advanced functional MIP nanoparticles-based chemosensor was also successfully utilized for the direct, sensitive, and accurate determination of Tc in another biological medium (i.e., the undiluted pig serum) with average recoveries ranging from 98% to 102%, even in the presence of several interfering drugs.

Recently, ultra-weak chemiluminescence (CL) systems have become one of the focuses of increasing attention. As one of them, H2O2-K3Fe(CN)6 system had also been studied. However, no attempts had been made to investigate the analytical applications of this system based on carbon dots (CDs). In this paper, nitrogen-doped carbon dots (FNCDs) were synthesized using formaldehyde as a coreactant, and it acted as a new fluorophore instead of conventional fluorescent dyes to enhance the CL signal of H2O2-K3Fe(CN)6 system, in which the excited-state FNCDs was the final emitting species, and was probably produced by the electron transfer and energy from reactive oxygen species. Interestingly, tannic acid (TA) could dramatically suppress the CL intensity of FNCDs-H2O2-K3Fe(CN)6 system. Under the optimum conditions, a linear relationship existed between reduced CL intensity and logarithm of TA concentration in range between 0.2 and 10.0 μM with a detection limit of 39.3 nM. The method was applied to the quantitative analysis of TA concentration in red wine.

We firstly proposed a ratiometric fluorescent nanoprobe with aptamer-labeled CdTe quantum dots (QDs) for the determination of zearalenone (ZEN). The nanoprobe was designed with dual-color emission fluorescence by single-wavelength excitation. Red-emitting silica-coated QDs (r-QDs@SiO2) with the maximum excitation/emission at 400/608 nm were used as a reference. Green-emitting QDs linked with aptamer and covalently bonded to r-QDs@SiO2 with the maximum excitation/emission at 400/518 nm were used as the responsive fluorophore for specific recognition of ZEN. The green fluorescence was quenched in the presence of ZEN. The ratio of fluorescence at 518 nm/608 nm decreased linearly against the increase of ZEN concentrations in the range of 31.4-628 nmol/L. The color of the solution changed from green to red as the concentration of ZEN increased. This method offered a ratiometric, specific and visual determination of ZEN. The limit of detection was 7.5 nM. The aptamer-labeled ratiometric strategy showed acceptable stability and selectivity. Therefore, the approach was successfully used to measure ZEN in food and can provide guidance for the design of point-of-care, multiplexed biosensors.