Nanofibers featuring functional nanoassemblies show great promise as enabling constituents for a diverse range of applications in areas such as tissue engineering, sensing, optoelectronics, and nanophotonics due to their controlled organization and architecture. An infusion gyration method is reported that enables the production of nanofibers with inherent biological functions by simply adjusting the flow rate of a polymer solution. Sufficient polymer chain entanglement is obtained at Berry number > 1.6 to make bead‐free fibers integrated with gold nanoparticles and proteins, in the diameter range of 117–216 nm. Integration of gold nanoparticles into the nanofiber assembly is followed using a gold‐binding peptide tag genetically conjugated to red fluorescence protein (DsRed). Fluorescence microscopy analysis corroborated with Fourier transform infrared spectroscopy (FTIR) data confirms the integration of the engineered red fluorescence protein with the nanofibers. The gold nanoparticle decorated nanofibers having red fluorescence protein as an integral part keep their biological functionality including copper‐induced fluorescence quenching of the DsRed protein due to its selective Cu+2 binding. Thus, coupling the infusion gyration method in this way offers a simple nanoscale assembly approach to integrate a diverse repertoire of protein functionalities into nanofibers to generate biohybrid materials for imaging, sensing, and biomaterial applications.
Aligned poly(l ‐lactide)/poly(methyl methacrylate) binary blend fibers and mats loaded with a chimeric green fluorescence protein having a bioactive peptide with hydroxyapatite binding and mineralization property are prepared by pressurized gyration. The effect of processing parameters on the product morphologies, and the shape memory properties of these samples are investigated. Integration of hydroxyapatite nanoparticles into the fiber assembly is self‐directed using the hydroxyapatite‐binding property of the peptide genetically engineered to green fluorescence protein. Fluorescence microscopy analysis corroborated with Fourier transform infrared spectroscopy (FTIR) data confirms the integration of the chimeric protein with the fibers. An enzyme based remineralization assay is conducted to study the effects of peptide‐mediated mineralization within the fiber mats. Raman and FTIR spectral changes observed following the peptide‐mediated mineralization provides an initial step toward a soft‐hard material transition. These results show that programmable shape memory properties can be obtained by incorporating genetically engineered bioactive peptide domains into polymer fibers.
The influence of solute hydrophobicity and charge on partitioning and diffusion in physically crosslinked networks of a genetically engineered SELP polymer was investigated. A series of fluorescent dyes were used to assess the impact of solute charge and hydrophobicity on release behavior. The mechanism of solute release from the SELP hydrogel appeared to vary as a function of dye hydrophobicity. The extent of FITC attachment to amine‐terminated G4 dendrimers influenced SELP hydrogel partitioning more than dendrimer diffusion properties. Results suggest the possibility of controlling solute release from SELP hydrogels by modifying the hydrophobicity and surface charge of drugs and drug/polymer conjugates as well as the possibility of “designing‐in” solute‐specific interactions.
Haptens of dichlorvos and paraoxon were conjugated to the carrier proteins of bovine serum albumin. The obtained conjugates were characterized by infrared and ultraviolet–visible spectroscopy. The binding ratios of dichlorvos and paraoxon-to-carrier proteins were also evaluated. The number of hapten molecules per protein molecule of dichlorvos–cationized bovine serum albumin conjugate was higher than for paraoxon–bovine serum albumin conjugate. The sheep polyclonal antibodies were produced against the dichlorvos and paraoxon. New multipolyclonal antibodies were obtained and characterized following the immunization of a 1:1 mixture of the immunogens for the simultaneous determination of dichlorvos and paraoxon by the immunoassay. An indirect enzyme-linked immunosorbent assay was used to characterize the reactivity of the antibodies to hapten conjugates. The multiantibodies showed lower affinities than the separate antibodies, but their affinities were sufficient for an immunoassay for the simultaneous determination of the analytes. The detection limit and linear range for the determination of dichlorvos and paraoxon alone and together were determined. The recovery was characterized to determine dichlorvos and paraoxon fortified in model solutions and milk. These results demonstrate the potential of this immunoassay for the quantitative screening of dichlorvos and paraoxon. 相似文献
Analytical limitations have constrained the determination of nanopollution character from real-world sources such as nano-enabled products (NEPs), thus hindering the development of environmental safety guidelines for engineered nanomaterials (ENMs). This study examined the properties of ENMs in 18 commercial products: sunscreens, personal care products, clothing, and paints—products exhibiting medium to a high potential for environmental nanopollution. It was found that 17 of the products contained ENMs; 9, 3, 3, and 2 were incorporated with nTiO2, nAg, binaries of nZnO + nTiO2, and nTiO2 + nAg, respectively. Commonly, the nTiO2 were elongated or angular, whereas nAg and nZnO were near-spherical and angular in morphology, respectively. The size ranges (width × length) were 7–48 × 14–200, 34–35 × 37–38, and 18–28 nm for nTiO2, nZnO, and nAg respectively. All ENMs were negatively charged. The total concentration of Ti, Zn, and Ag in the NEPs were 2.3 × 10−4–4.3%, 3.4–4.3%, and 1.0 × 10−4–11.3 × 10−3%, respectively. The study determined some key ENM characteristics required for environmental risk assessment; however, challenges persist regarding the accurate determination of the concentration in NEPs. Overall, the study confirmed NEPs as actual sources of nanopollution; hence, scenario-specific efforts are recommended to quantify their loads into water resources. 相似文献
ABSTRACT There are many compounds that require analysis ranging from pesticide levels in corn to disease markers in human patients. There are copious challenges to be met when measuring analytes such as the matrix in which they are to be determined, the amounts present, the cost and the rapidity of the result required. Enzyme immunoassays, immunoaffinity chromatography, immunomagnetic polymerase chain reaction, flow cytometry and immunobiological biosensors have all characteristics that can enhance analytical techniques. Antibody-based methods have found applications in a large number of diverse areas such as food and water analysis, clinical diagnosis and therapeutics The structure and modes of production of antibodies and antibody-based derivatives is described and their applications in analysis critically examined. 相似文献
