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In this work, a metal–organic framework MIL-68(In)–NH2 incorporated high internal phase emulsion polymeric monolith (MIL-68(In)–NH2/polyHIPE) was prepared and applied as a solid phase extraction adsorbent for the extraction and detection of trace triazine herbicides in environmental water samples by coupling with HPLC-UV detection. The fabricated material showed good adsorption for simazine, prometryn, and prometon in water samples because of π–π interactions and hydrogen bonding interactions. Under optimal conditions, the maximum adsorption capacity of simazine, prometon and prometryn was 800 μg g−1, 800 μg g−1 and 6.01 mg g−1, respectively. The linearities were 10–800 ng mL−1 for simazine, prometon and prometryn. The limits of detection were 31–97 ng L−1, and the recoveries were 85.6–118.2% at four spiked levels with relative standard deviations lower than 5.0%. The method has a high sensitivity for the determination of three triazine herbicides in environmental water samples.

A new nanopore array/Au electrode was fabricated and applied to the detection of microRNA. The electrode was prepared via alternating current electrodeposition of Au nanowires in the nanopores of a porous anodic alumina membrane (without the need to remove aluminum or any barrier layer). The internal surface of the nanopores was then functionalized with an electrically neutral morpholino with a specially designed sequence. The resulting electrode shows excellent sensitivity and selectivity in detection of the target miRNA-155. The detection limit is 10 aM and the linear range 10 aM–1 nM in aqueous solution and the electrode can be reused in 6 M urea solution. In addition, it shows good linearity (100 aM–0.1 nM) in a serum sample. This new biosensor is expected to enhance miRNA detection in clinical diagnosis. Keywords: Nanopores, Label-free detection, microRNA, Porous anodic alumina

An Aflatoxin B1 (AFB1) biosensor was fabricated via an Ag nanoparticles assembly on the surface of a porous anodized aluminum (PAA) membrane. First, the Raman reporter 4-Aminothiophenol (4-ATP) and DNA (partially complementary to AFB1 aptamer) were attached to the surface of Ag nanoparticles (AgNPs) by chemical bonding to form a 4-ATP-AgNPs-DNA complex. Similarly, the surface of a PAA membrane was functionalized with an AFB1 aptamer. Then, the PAA surface was functionalized with 4-ATP-AgNPs-DNA through base complementary pairing to form AgNPs-PAA sensor with a strong Raman signal. When AFB1 was added, AgNPs would be detached from the PAA surface because of the specific binding between AFB1 and the aptamer, resulting in a reduction in Raman signals. The detection limit of the proposed biosensor is 0.009 ng/mL in actual walnut and the linear range is 0.01&ndash, 10 ng/mL. The sensor has good selectivity and repeatability, it can be applied to the rapid qualitative and quantitative detection of AFB1.

A novel aflatoxin B1 biosensor is fabricated from a porous anodized alumina membrane modified with graphene oxide and an aptamer of aflatoxin B1. Briefly, the aptamer is immobilized on the surface of the porous anodized alumina nanochannels by covalent bonding. Graphene oxide is then added to the surface by π-π stacking with the aptamer. The negative charge of the nanochannels is increased by the introduction of the negatively charged graphene oxide and the aptamer, which also cause steric hindrance. On the addition of aflatoxin B1, graphene oxide is detached from the surface of the nanochannels due to the specific binding of aflatoxin B1 to the aptamer. The flux of Fe(CN)63− through the nanochannels is increased because the charge density and steric hindrance are reduced, resulting in an increased current response. The increase in current is proportional to the concentration of aflatoxin B1. The detection limit of the proposed biosensor is about 0.13 ng/mL and the linear range is 1–20 ng/mL. Furthermore, this sensor has excellent selectivity towards aflatoxin B1, offering the potential for a sensitive, simple and effective method for detecting mycotoxins. Keywords: Biosensor, Nanochannels, Aptamer, Graphene oxide, Porous alumina membrane, Aflatoxin B1

The microstructure of hydroxyapatite is known to influence cellular behavior, can be used as a substrate for osteoblast growth, and exploited as a drug-release platform. However, easy delamination and self-decomposition of hydroxyapatite caused by poor adhesion with substrates are the main problems currently. In this paper, we successfully fabricated titanium dioxide/strontium-doped hydroxyapatite (TiO2/SrHA) composite scaffolds by self-generated strontium-substituted hydroxyapatite microspheres in TiO2 nanotubes. Moreover, the active compound 1-(5-bromo-2-hydroxy-methoxyphenyl)-ethanone (BHM) from Seahorse (Hippocampus kuda Bleeler) was loaded in this scaffold, and the controlled release kinetics of BHM was studied. It was found that in the first 5 h, the release concentration and time of BHM had a good linear relationship, and the correlation coefficient reached 0.98. TiO2/SrHA/BHM composites exhibited favorable cytocompatibility at a given concentration of BHM (20 μmol/L). Compared to pure SrHA, TiO2 n...

A mussel-inspired new interfacial ionic rectification device is fabricated using porous anodic alumina nanochannels and graphene oxide via dopamine polymerization. In addition, the rectification mechanism is elucidated based on the principles of physics and thermodynamics via finite element simulation and the results show that the interface distance and surface charge play a vital role in ion transport.

Au nanoclusters were synthetized through chemical reduction based on glutathione template. The fluorescence excitation and emission wavelength is 375 nm and 565 nm, respectively. The fluorescence would be quenched at the presence of ferrous and hydrogen peroxide and recovered as ascorbic acid added. It can be used for qualitative analysis of ascorbic acid according to fluorescence recovery. The fluorescence intensity is positive correlation with the concentration of ascorbic acid. The detection limit is 200 μM and linear range is 350–700 μM. It offers an easy and convenient method to detect of ascorbic acid.

A sensitive and intuitive freshness intelligent label was fabricated for indicating the freshness of fish based on porous anodic aluminum (PAA) membrane and bromocresol green. This label is fabricated by the bromocresol green (BCG) immobilized on PAA membrane, which responds through visible color change to the total volatile basic nitrogen (TVBN) released during fish spoilage period. The result showed that the fish is inedible when it was stored at 25 °C for 6 h (TVBN > 20 mg/100 g). Under this condition, the color of BCG/PAA label changed from yellow to green obviously. In addition, BCG/PAA membrane label and the electrospinning nanofiber label were used to evaluate the fish freshness. As a result, the color of BCG/PAA membrane label is more obvious and sensitive. Thus, BCG/PAA membrane label can be considered as a new promising method for the assessment of fish freshness.

A novel low temperature chitosan hydrogel (

Abalone (Haliotis discus hannai) is a precious seafood in the market. It has been reported that biological active substances derived from abalone have anti-oxidative, anti-inflammatory, anti-bacterial, and anti-thrombosis potential. However, there were few studies to assess whether they have anti-cancer potential. In this study, we evaluated the anti-metastasis and anti-pro-angiogenic factors and mechanism of action of boiled abalone byproduct peptide (BABP, EMDEAQDPSEW) in human fibrosarcoma (HT1080) cells and human umbilical vein endothelial cells (HUVECs). The results demonstrated that BABP treatment significantly lowers migration and the invasion of HT1080 cells and HUVECs. BABP inhibits phorbol 12-myristate 13-acetate (PMA)-induced matrix metalloproteinase (MMP) expression and activity by blocking mitogen-activated protein kinases (MAPKs) and NF-κB signaling and hypoxia-induced vascular endothelial growth factor (VEGF) secretion and hypoxia inducible factor (HIF)-1α accumulation through suppressing the AKT/mTOR signal pathway. BABP treatment inhibits VEGF-induced VEGFR-2 expression and tube formation in HUVECs. The effect of BABP on anti-metastatic and anti-vascular activity in HT1080 cells and HUVECs revealed that BABP may be a potential pharmacophore for tumor therapy in the future.

A method is developed for detecting the concentration of sodium thiocyanate (NaSCN) in milk based on surface-enhanced Raman scattering (SERS) technology. A trichloroacetic acid solution can be used to enhance the SERS signal because of its function in promoting the aggregation of Ag nanoparticles (Ag NPs). Meanwhile, the protein in milk would be precipitated as trichloroacetic acid added and the interference from protein could be reduced during the detection. In this work, the enhancement factor (EF) is 7. 56 &times, 105 for sodium thiocyanate in water and the limit of detection (LOD) is 0.002 mg/L. Meanwhile, this method can be used to detect the concentration of sodium thiocyanate in milk. Results show that SERS intensity increased as the concentration of sodium thiocyanate increase from 10 to 100 mg/L. The linear correlation coefficient is R2 = 0.998 and the detection limit is 0.04 mg/L. It is observed that the concentration of sodium thiocyanate does not exceed the standard in the three kinds of milk. The confirmed credibility of SERS detection is compared with conventional methods.

In this Letter, we proposed a nanoporous sensor to realize a quick and sensitive detection of Listeria monocytogenes with the application of porous anodic aluminum oxide membrane combined with a specific aptamer. On the basis of electrochemical detection, it can be known that the reduction current response upon the diffusion flux of electrochemical probe is affected by the charge repulsion and steric blockage of Listeria monocytogenes. A rapid bacteria detection can be achieved within 10 min, with a high sensitivity of 100 CFU/mL and a good linear range between 100 to1250 CFU/mL. Moreover, it has a high specificity for Listeria monocytogenes even exposed in 108 CFU/mL Staphylococcus aureus or Escherichia coli.

A degradable and antibacterial sodium alginate film containing functional Au-TiO2 nanocomposites for food packaging was successfully developed. The Au-TiO2 nanocomposites are synthesized hydrothermally and mixed with the alginate solution to form the film by a casting method. The Au-TiO2 nanocomposites enable the film with excellent visible light absorption and transfer ability with the light absorption rang covering UV&ndash, visible wavelength (300&ndash, 800 nm) and induce the increase of the film water contact angle from 40&deg, to 74&deg, which contributes to the film shape stability. Furthermore, compared to the TiO2 nanoparticle-incorporated film, the antibacterial ability of Au-TiO2/sodium alginate composite film is improved approximately by 60% and 50% against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively, in light conditions. The antibacterial property of the film arises from the increased production of reactive oxygen species (ROS) induced by the surface plasmonic resonance of Au nanoparticles. The degradable and antibacterial properties render the composite film of great application potential in food packaging industry.

Prodrug, in which the inactive parent drug with good bioavailability is metabolized into an active drug in the body, is one of the main strategies to target the disease site to improve the drug efficiency and reduce the adverse effects of chemotherapy. Because of the good capability of chemical modification, zein, a plant derived protein, and drugs can be conjugated through environmentally sensitive links to form prodrugs capable of triggered drug release. In this study, a novel prodrug was synthesized using paclitaxel (PTX), zein, and a disulfide linker, and nanoparticles were formed by self-assembly of the prodrug. An effective in vitro triggered release, 80-90% in 5 min, of the prodrug based nanoparticles (zein-S-S-PTX_NP) was successfully approached. The cytotoxicity of zein-S-S-PTX_NP as well as the zein encapsulation of PTX (zein_PTX_NP) and pure PTX on HeLa cells and NIH/3T3 fibroblast cells was tested using MTS assay. It showed that, after the treatment of zein-S-S-PTX_NP at the equivalent PTX concentrations of 0.1, 0.5, 1, and 5 μg/mL, respectively, zein-S-S-PTX_NP had zero damage to normal cells but a similar cytotoxicity to cancer cells as pure PTX. In the animal study, the tumor was 50% of the original size after the treatment of zein-S-S-PTX_NP for 9 days with 3 doses. This study suggested that the novel prodrug based nanoparticle zein-S-S-PTX_NP could be a promising approach in chemotherapy with targeted delivery, improved efficacy, and reduced side effects.

A highly sensitive nitrite (NO2&minus, ) electrochemical sensor is fabricated using glassy carbon electrode modified with Au nanoparticle and grapheme oxide. Briefly, this electrochemical sensor was prepared by drop-coating graphene oxide-chitosan mixed film on the surface of the electrode and then electrodepositing a layer of Au nanoparticle using cyclic voltammetry. The electrochemical behavior of NO2&minus, on the sensor was investigated by cyclic voltammetry and amperometric i-t curve. The results showed that the sensor exhibited better electrocatalytic activity for NO2&minus, in 0.1 mol/L phosphate buffer solution (PBS) (pH 5.0). The oxidation peak current was positively correlated with NO2&minus, concentration in the ranges of 0.9 &micro, M to 18.9 &micro, M. The detection limit was estimated to be 0.3 &micro, M. In addition, the interference of some common ions (e.g., NO3&minus, CO32&minus, SO42&minus, Cl&minus, Ca2+ and Mg2+) and oxidizable compound including sodium sulfite and ascorbic acid in the detection of nitrite was also studied. The results show that this sensor is more sensitive and selective to NO2&minus, Therefore, this electrochemical sensor provided an effective tool for the detection of NO2&minus

TiO2 nanotubes/Au nanoparticles/enzyme photoelectrochemical biosensor is developed by the chemical bonding of acetylcholinesterase with Au nanoparticles-modified TiO2 photoactive electrode, based on the inhibitory effect of aflatoxin B1 on acetylcholinesterase activity. In this method, AuNPs were deposited on the surface of the electrode by potentiostatic deposition and the acetylcholinesterase was chemically crosslinked to the surface for determination of aflatoxin B1. Enzymatic hydrolysate is generated to capture the photogenerated holes of UV-sensitized TiO2 nanotube arrays, causing magnification of the photoelectrochemical signal. The photoelectrochemical biosensor morphological and structural details were evaluated, applying different techniques, such as X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Aflatoxin B1 competitively inhibits acetylcholinesterase, leading to a decrease in photocurrent that should have been increased. The detection performance of biosensors for different concentrations of AFB1 is discussed. The linear response range of the biosensor is from 1–6 nM with detection limitation of 0.33 nM, the linear equation is I (μA) = −0.13C (nM) + 9.98 (μA), with a correlation coefficient of 0.988. This new biosensor could be used to detect Aflatoxin B1 in foods.

Cadmium selenide (CdSe) quantum dots (QDs) were synthesized by water phase synthesis method using 3-mercaptopropionic acid (3-MPA) as a stabilizer, and they were applied to the detection of copper ions (Cu2+). The results showed that CdSe QDs have excellent selectivity and sensitivity toward Cu2+. The fluorescence intensity of CdSe QDs decreased with the increase of Cu2+ concentration. The linear range was from 30 nM to 3 &mu, M, and the detection limit was 30 nM. Furthermore, CdSe QDs were used for detecting the concentration of Cu2+ in oysters. The content of Cu2+ was 40.91 mg/kg, which was close to the one measured via flame atomic absorption spectrometry (FAAS), and the relative error was 1.81%. Therefore, CdSe QDs have a wide application prospect in the rapid detection of copper ions in food.

A simple and sensitive Pb[Formula: see text] sensor is developed based on label-free 17E DNAzyme and unmodified Au nanoparticles. On this basis, Pb[Formula: see text] concentration can be judged according to the color variation of Au nanoparticles. The detection limit is 100[Formula: see text]nM and linear range is 100[Formula: see text]nM–16[Formula: see text][Formula: see text]M. It can serve as a measurement tool for Pb[Formula: see text] rapid detection, which provides reference for the development of sensors in environmental monitoring and food safety.

A sensitive and fast sensor for quantitative detection of organophosphorus pesticides (OPs) is obtained using acetylcholinesterase (AChE) biosensor based on graphene oxide (GO)–chitosan (CS) composite film. This new biosensor is prepared via depositing GO–CS composite film on glassy carbon electrode (GCE) and then assembling AChE on the composite film. The GO–CS composite film shows an excellent biocompatibility with AChE and enhances immobilization efficiency of AChE. GO homogeneously disperses in the GO–CS composite films and exhibits excellent electrocatalytic activity to thiocholine oxidation, which is from acetylthiocholine catalyzed by AChE. The results show that the inhibition of carbaryl/trichlorfon on AChE activity is proportional to the concentration of carbaryl/trichlorfon. The detection of linear range for carbaryl is from 10[Formula: see text]nM to 100[Formula: see text]nM and the correlation coefficients of 0.993. The detection limit for carbaryl is calculated to be about 2.5[Formula: see text]nM. In addition, the detection of linear range for trichlorfon is from 10[Formula: see text]nM to 60[Formula: see text]nM and the correlation coefficients of 0.994. The detection limit for trichlorfon is calculated to be about 1.2[Formula: see text]nM. This biosensor provides a new promising tool for trace organophosphorus pesticide detection.