Paper, with advantages of low-cost, easy fabrication and disposal, flexibility and renewability, is a suitable substrate material for various applications. Functionalization and patterning on paper substrates are commonly required in many applications. Although many methods have been developed to achieve this, they typically suffer from some drawbacks such as time-consuming process, specific device dependence, lack of flexibility, low patterning resolution, and so forth. Herein, we present a general and fast method to functionalize paper sheets and create patterns. The whole modification process can be completed in 10 min and can be applied on various types of paper substrates and other natural materials such as natural fabrics. By our method, many commonly used functional groups can be covalently attached and patterned on paper substrates, while the characteristic features of the original paper substrates, for example, color, transparency, and conductivity, can be perfectly retained after modification to allow these properties to be incorporated into the resultant materials. High-resolution patterns can be created on paper by applying a photomask during the modification or controlling the time of modification to precisely control the functionality at any area on the obtained paper substrates. We also show the potential applications of our method in the fabrication of superhydrophobic coatings and biomaterials.

Bioinspired re‐entrant structures have been proved to be effective in achieving liquid superrepellence (including anti‐penetration, anti‐adhesion, and anti‐spreading). However, except for a few reports relying on isotropic etching of silicon wafers, most fluorination‐dependent surfaces are still unable to repel liquids with extreme low surface energy (i.e., γ < 15 mN m−1), especially those fluorinated solvents. Herein, triply re‐entrant structures, possessing superrepellence to water (with surface tension γ of 72.8 mN m−1) and various organic liquids (γ = 12.0–27.1 mN m−1), are fabricated via two‐photon polymerization based 3D printing technology. Such structures can be constructed both on rigid and flexible substrates, and the liquid superrepellent properties can be kept even after oxygen plasma treatment. Based on the prepared triply re‐entrant structures, micro open capillaries are constructed on them to realize directional liquid spreading, which may be applied in microfluidic platforms and lab‐on‐a‐chip applications. The fabricated arrays can also find potential applications in electronic devices, gas sensors, microchemical/physical reactors, high‐throughput biological sensors, and optical displays.

In article number 1800103, Zhongze Gu and co-workers fabricate liquid (γ = 12.0–27.1 mN m−1) superrepellent re-entrant structures via two-photon-polymerization-based 3D-printing technology. The fabricated arrays can find potential applications in microfluidic platforms, lab-on-a-chip electronic devices, gas sensors, microchemical/physical reactors, high-throughput biological sensors, and optical displays.

Superhydrophobic (SH) surfaces have held great promise during the last decade because of their diverse potential applications as self‐cleaning surfaces, in microfluidics, microarrays, etc. Recently, reactive SH surfaces combining their liquid‐repellency with the possibility for convenient postfunctionalization and patterning were introduced. However, current concepts for making reactive SH materials have very limited selection of “hydrophobic as well as reactive” groups. Here a novel reparable SH surface with hidden reactivity (SuSHiR) based on photodynamic properties of disulfides is reported. Reactive hydrophobic, SH, as well as superhydrophilic surfaces are fabricated using this method. The method allows the use of diverse end functionalities (reactive or nonreactive, hydrophobic, or hydrophilic), while keeping the same reactive disulfides “hidden” in the middle of the functional surface‐grafted chains. The photoreactivity of the disulfide bond allows for the functionalization and patterning of various molecules through UV irradiation. The obtained SuSHiR exhibits better stability compared to conventional reactive SH surfaces, and the reversibility of the disulfide–disulfide exchange reaction enables reversible patterning as well as photorestoration of damaged functionalities.

A method for the determination of 16 polycyclic aromatic hydrocarbons in water has been developed. First, we made a solid-phase extraction column. After this, the parameters affecting the efficacy of the experimental method were optimized, including appropriate selection of a solid-phase extraction column and cleanup conditions on columns. The separation was achieved by gas chromatography and detection with triple quadrupole tandem mass spectrometry. The method showed satisfactory linearity (R2  > 0.999) over the range assayed (0.01-1 μg/mL), and limits of quantification ranging from 0.0011 to 0.0199 μg/L. The recoveries ranged from 83 to 113%. The relative standard deviation is in the range 0.86-3.1%. The results indicated that this method had high selectivity and precision that was suitable for the simultaneous determination of 16 polycyclic aromatic hydrocarbons in water.

Nylon 6 electrospun nanofibers mat was prepared via electrospinning for the removal of three estrogens, namely, diethylstilbestrol (DES), dienestrol (DS), and hexestrol (HEX) from aqueous solution. Static adsorption as well as the dynamic adsorption was evaluated by means of batch and dynamic disk flow mode, respectively. The kinetic study indicated that the adsorption of the target compounds could be well fitted by the pseudo-second-order equation, suggesting the intra-particle/membrane diffusion process as the rate-limiting step of the adsorption process. The adsorption equilibrium data were all fitted well to the Freundlich isotherm models, with a maximum adsorption capacity values in the range of 97.71 to 208.95 mg/g, which can be compared to or moderately higher than other sorbents published in the literatures. The dynamic disk mode studies indicated that the mean removal yields of three model estrogens were over 95% with a notable smaller amount of adsorbent (4 mg). Thermodynamic study revealed that the adsorption process was exothermic and spontaneous in nature. Desorption results showed that the adsorption capacity can remain up to 80% after seven times usage. It was suggested that Nylon 6 electrospun nanofibers mat has great potential as a novel effective sorbent material for estrogens removal.

A simple, rapid and sensitive method for the determination of diethylstilbestrol (DES), dienestrol (DE) and hexestrol (HEX) was developed by using the Nylon 6 nanofibers mat-based solid-phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS). These estrogens were separated within 8 min by LC using an ODS column and methanol/water (80/20, v/v) at a flow rate of 1.0 mL min(-1). Electrospray ionization conditions in the negative ion mode were optimized for MS detection of the estrogens. Under the optimum SPE conditions, all target analytes in 50 mL environmental water samples can be completely extracted by 1.5 mg Nylon 6 nanofibers mat at flow rate of 3.0 mL min(-1) and easily eluted by passage of 500 mu L mobile phase. By using the novel SPE-LC/MS method, good linearity of the calibration curve (r(2) >= 0.9992) was obtained in the concentration range from 0.10 ng L(-1) to 1.0 mg L(-1) (except for DE which was 0.20 ng L(-1) to 1.0 mg L(-1)) for all analytes examined. The limits of detection (S/N = 3) of the three estrogens ranged from 0.05 ng L(-1) to 0.10 ng L(-1). This method was applied successfully to the analysis of environmental water samples without any other pretreatment and interference peaks. Several water samples were collected from Jinchuan River and Xuanwu Lake, and in Jinchuan River water DES was detected at 0.13 ng L(-1). The recoveries of estrogens spiked into tap water were above 98.2%, and the relative standard deviations were below 4.78%.

In this article, a new method for simultaneous determination of six phthalate esters was developed by a combination of electrospun nylon6 nanofibers mat-based solid phase extraction with high performance liquid chromatography-ultraviolet detector (HPLC-UV). The six phthalate esters were dimethyl phthalate (DMP), diethyl phthalate (DEP), butyl benzyl phthalate (BBP), di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and dioctyl phthalate (DOP). Under optimized conditions, all target analytes in 50 mL environmental water samples could be completely extracted by 2.5 mg nylon6 nanofibers mat and eluted by 100 mu L solvent. Compared with C18 cartridges solid phase extraction, C18 disks solid phase extraction and national standard method (China), nylon6 nanofibers mat-based solid phase extraction was advantageous in aspects of simple and fast operation, low consumption of extraction materials and organic solvents. The four methods were applied to analysis of environment water samples. All the results indicated that the determination values of target compounds with the proposed method were consistent with C18 cartridges and C18 disks solid phase extraction method, and the new method was better than the national standard method in aspects of recovery, LOD and precision. Therefore, nylon6 nanofibers mat has great potential as a novel material for solid phase extraction.

A method was developed to determine ketoconazole enantiomers in rabbit plasma by polyamide 6 nanofibers mat-based solid phase extraction and chiral mobile phase additive method following high-performance liquid chromatography. Only 1. 5 mg of polyamide 6 nanofibers membrane and 100 μL methanol can complete the enrichment and the elution of the target material. Calibration curves were linear over the range of 50. 0 400. 0 μg/L for each enantiomer. The limit of quantitation was 40. 0 μg/L for each enantiomer. The intra-day and inter-day relative standard deviation was 4. 3% and 7. 6% ,respectively. The average absolute recoveries and relative recoveries were 79. 4% 85. 6% and 98. 0% 102. 2% ,respectively. This method is sensitive,accurate,reproducible,and can meet the requirements of the determination of ketoconazole enantiomers in biological samples.

A simple and sensitive HPLC method was established and validated for the determination of docetaxel (DTX) in rabbit plasma. Biosamples were spiked with paclitaxel (PCX) as an internal standard (I.S.) and pre-treated by solid-phase extraction (SPE). The SPE procedure followed a simple protein digestion was based on nylon6 electrospun nanofibers mats as sorbents. Under optimized conditions, target analytes in 500 μL of plasma sample can be completely extracted by only 2.5 mg nylon6 nanofibers mat and eluted by 100 μL solvent. The HPLC separation was obtained on C18 column and UV detector was used to quantify the target analytes. The extraction recovery was more than 85%; the standard curve was linear over the validated concentrations range of 10–5000 ng/mL and the limit of detection was 2 ng/mL. The inter-day coefficient of variation (CV%) of the calibration standards was below 5.0% and the mean accuracy was in the range of 92.8–113.4%. Moreover, analysing quality control plasma samples in 3 days, the results showed that the method was precise and accurate, for the intra- and inter-day CV% within 10% and the accuracy from 96.0% to 114.0%. The developed and validated method was successfully applied to relative bioavailability study for the preclinical evaluation of a new injectable DTX–sulfobutyl ether beta-cyclodextrin (DTX–SBE-β-CD) inclusion complex freeze-dried powder (test preparation), compared with the reference preparation (DTX injection, Taxotere®) in healthy rabbits. On the basis of the mean AUC(0–t) and AUC(0–infinity), the relative bioavailability of the test preparation was found to be 113.1%.

A new method for simultaneous determnation of six phthalate esters in commercial milk was developed by the combination of latest proposed PA6 nanofibers mat-based solid-phase extraction with high-performance liquid chromatography-ultraviolet detector(HPLC-UV). Conditions for obtaining optimum extraction efficiency such as extraction solvents and its volume, extraction time, eluant and its volume, amount of adsorbent, pH, flow rate of sample were investigated and optimized in detail. Under optimized conditions, the detection limits found for dimethyl phthalate (DMP), diethyl phthalate(DEP), butylbenzyl phthalate(BBP), dibutyl phthalate(DBP), diethyl hexylphthalate(DEHP) and dioctyl phthalate (DOP) were 0.02, 0.01, 0.05, 0.05, 0.10 and 0.25 ng/mL, respectively. The proposed method was applied to the analysis different brands and packaging of milk samples. PAEs in commercial milk samples can be completely extracted by 2.5 mg PA6 nanofiber mat. The satisfactory spiked recoveries were obtained in the range of 93.40%-104.83% with relative standard deviation (RSD) of below 5.82% were achieved. The main advantages of the method are low detection limits, high sensitivity and selectivity and the results are accurate and reliable, reproducible.

The concentrations and distribution features of 6 phthalate esters (PAEs) in the samples collected from Xuanwu Lake, i.e. DMP(dimethyl phthalate), DEP(diethyl phthalate), BBP(butylbenzyl phthalate), DBP(di-n-butyl phthalate), DEHP(diethylhexyl phthalate), and DOP(di-n-octyl phthalate), are analyzed by nylon6 nanofibers mat-based solid-phase extraction coupled with high-performance liquid chromatography. The results show that the concentrations of the PAEs range from 861 to 2896 μg/L, with an average concentration of 1368 μg/L. The concentrations of the PAEs in the southeast lake are much higher than in the other parts of the lake. And the concentrations of the PAEs in the center of the lake are higher than those at the edge area. Among the six studied PAEs, DBP and DEHP are the main pollutants, which account for 83.00% to 94.65% of the total PAEs, respectively. Compared with other water bodies at home and aboard, Xuanwu Lake is heavily polluted. Therefore, more attention should be paid to the pollutant control.

A new method for determining bisphenol A (BPA) in plastic bottled drinking water was developed by the combination of electrospun nylon6 nanofibers membrane-based solid-phase extraction with high performance liquid chromatography-ultraviolet (HPLC-UV) detector. Important parameters affecting extraction efficiency such as eluant and its volume, flow rate of sample, sample volume, pH value of sample, the amount of membrane and the reusability of this membrane were optimized. Results indicate that 10 mL of water sample volume passed through nylon6 nanofibrous membrane at a flow rate of 3.0 mL min−1, only 1.5 mg of membrane and 300 μL of eluant were sufficient for the adsorption and desorption of BPA in the samples. Each piece of this membrane could be used at least 6 times. Under optimized conditions, an excellent linear relationship in a range of 0.2–20 μg L−1 with determined coefficient (r) 0.9998 was obtained, the limits of detection for BPA was 0.15μg L−1. The relative standard deviation (RSD %) of intramembrane and intermembrane with nylon6 nanofibrous membrane were all less than 4.5% (n = 6). The proposed method has been applied to the analysis of plastic bottled purified water of six different brands. Satisfactory recovery (95.0%) was obtained at a spiked level of 1.0 μg L−1. BPA was detected via a range of 0.20–0.30 μg L−1. A comparison between the solid-membrane extraction (SME) via nylon6 nanofibrous membrane and SPE via other sorbents used in literatures was carried out. All the results indicate that as a novel material nylon6 nanofibrous membrane has a great potential for the enrichment and determination of BPA in water.

The migration of phthalates (PAEs), a class of typical environmental estrogen contaminants in food, from food packaging to packaged food attracts more and more attention worldwide. Many factors will affect the migration processes. The purpose of this study was to evaluate PAE migration from plastic containers to cooking oil and mineral water packed in authentic commercial packaging and stored under various conditions (different storage temperatures, contact times, and storage states (static or dynamic state)) and to identify a potential relationship between the amount and type of PAEs migrated and the lipophilic character of the food matrix. The samples were analyzed by a novel method of liquid chromatography combined with solid-phase extraction by an electrospun nylon 6 nanofibers mat, with PAE detection limits of 0.001 μg/L in mineral water and 0.020 μg/L in cooking oil, respectively. The results demonstrated that the cooking oil was a more suitable medium for the migration of PAEs from packages into foodstuffs than mineral water. Scilicet, the migration potential of the PAEs into foodstuffs, depends on the lipophilic characteristics of the food matrix. The results also demonstrated that migrations were more significant at higher temperature, longer contact time, and higher dynamic frequency; thus, the migration tests should be evaluated with consideration of different storage temperatures and contact times. Mathematical models with good logarithmic relationships were established to demonstrate the relationship between the PAE migration and food/packaging contact time for different storage temperatures. These established mathematical models would be expected to become a set of practical tools for the prediction of PAE migration.

In this paper, electrospun Nylon6 nanofibrous membrane was firstly used as adsorbent for solid membrane extraction (SME). The membrane was arranged as a disk in a home-made device, three estrogens-estradiol (E2), ethinylestradiol (EE2) and estrone (E1) in environmental water were extracted and then determined by liquid chromatography–ultraviolet detector (LC–UV). The important parameters affecting extraction efficiency were completely studied and optimized. The experimental results showed that only 1.5 mg Nylon6 nanofibrous membrane could make the maximum sample loading volume up to 50 mL and the target analytes were adsorbed effectively. Under the optimized conditions, the limits of detection (LOD) for E2, EE2, E1 were up to 0.05, 0.08, 0.17 ng mL−1 respectively and the repeatabilities (RSD%) of intra-membrane and inter-membrane were below 6.0% about spiked samples. The proposed method was subsequently applied to studying water samples from river, rain, pond and tap. Satisfactory spiked recoveries in the range of 85.3–95.9% at 0.25 ng mL−1 spiked level for the three estrogens were obtained. A comparison with commercial nylon microporous membrane and octadecylsilica (ODS) cartridges was also carried out. All the results showed that electrospun Nylon6 nanofibrous membrane, as a new adsorbent material has great potential for the enrichment of steroid estrogens in the water samples with satisfactory recovery and repeatability.

A simple and effective method for the separation of ketoconazole enantiomers was developed using the chiral mobile phase additive on a C-18 reversed-phase column. Several beta-cyclodextrins were investigated as chiral mobile phase additives separately. The results showed that ketoconazole enantiomers were well separated by only adding sulfobutyl ether-beta-cyclodextrin (SBE-beta-CD) into the mobile phase. Excellent enantioseparation was achieved with the mobile phase composed of methanol-0.02 mol/L NaH2PO4 (60:40, v/v, containing 1.0 mmol/L SBE-beta-CD and 0.02% triethylamine, at pH 3.00 adjusted with phosphoric acid aqueous solution). The flow rate was 1.0 mL/min. The detection wavelength was set at 225 nm and the column temperature at 30 degrees C. Under the optimized conditions, the resolution of ketoconazole enantiomers was 2.05.