Preparation of Hydrophilic Encapsulated Carbon Nanotubes with Polymer Brushes and Its Application in Composite Hydrogels

Carbon nanotubes can be used as promising reinforcement materials to improve the mechanical properties of hydrogels, but their poor dispersibility in aqueous solution severely limits their application in preparation of composite hydrogels. Therefore, to develop method for modification of carbon nanotubes is still highly desired. In this paper, a facile approach for preparation of the hydrophilic carbon nanotube was reported. The encapsulated multiwalled carbon nanotubes (E-CNT-PAA) with cross-linked shell structure were obatined through the self-assembly of the amphipathic azide diblock copolymers poly­(acrylic acid)-<i>b</i>-poly­(4-vinylbenzyl azide-<i>co</i>-styrene) (PAA-<i>b</i>-(PVBA-<i>co</i>-PS)), and the cross-linking of inside azide groups under UV irradiation. The encapsulated MWCNT was characterized by FT-IR, Raman and TEM. It was demonstrated that the dispersibility of the hydrophilic encapsulated MWCNTs was related to the length of the poly­(acrylic acid) brushes. Subsequently, thermal-responsive composite hydrogels (PNIPAM/E-CNT-PAA) were prepared by in situ polymerization of <i>N</i>-isopropylacrylamide (NIPAM) in the solution of dispersed E-CNT-PAA. The results showed that the composite hydrogels possessed high mechanical properties compared to the pure PNIPAM hydrogel. The tensile strength and elongation of the composite hydrogels were highly dependent on the content of the modified MWCNTs. The composite hydrogels with 0.46 wt % MWCNTs exhibited tensile strength of 97.7 kPa and elongation of 465%, which were at least 3.5× higher than those of the PNIPAM hydrogel. Moreover, the composite hydrogels displayed significant and reversible stimuli-responsiveness

Image_3_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.TIF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

Image_1_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.TIF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

Data_Sheet_1_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.PDF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

Image_6_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.TIF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

Image_2_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.TIF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

A Diheteroatom Fluoroalkylation Reagent for Preparation of S- and N‑Containing Fluoroalkyl Compounds and Sulfonic Acid Polymer

The first stable diheteroatom fluoroalkylation reagent, 2-((2-azido-1-chloro-1,2,2-trifluoro­ethyl)­thio)­pyrimidine (ACTP), has been prepared by a novel method. By using this reagent, various fluorinated thioethers and sulfones have been successfully prepared. The dearylation and dearylation–oxida­tion of fluoroalkyl 2-pyrimidyl sulfone in one-pot reaction were investigated systematically, and the results demonstrated that both fluoroalkyl sulfinates and sulfonates could be obtained in high yields. In addition, ACTP proved to be useful for the preparation of a fluorinated sulfonic acid proton-exchange membrane

Image_7_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.TIF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

Image_5_Visual and label-free ASFV and PCV2 detection by CRISPR-Cas12a combined with G-quadruplex.TIF

African swine fever (ASF) and postweaning multisystemic wasting syndrome (PMWS) are acute infectious diseases caused by the African swine fever virus (ASFV) and porcine circovirus type 2 (PCV2). At present, there are no effective vaccines for the prevention of ASFV. PMWS, which is harmful to the domestic and even the world pig industry, is difficult to cure and has a high mortality. So, developing simple, inexpensive, and accurate analytical methods to detect and effectively diagnose ASFV and PCV2 can be conducive to avoid ASFV and PCV2 infection. CRISPR has become a potentially rapid diagnostic tool due to recent discoveries of the trans-cleavage properties of CRISPR type V effectors. Herein, we report the visual detection based on CRISPR-Cas12a (cpf1), which is more convenient than fluorescence detection. Through in vitro cleavage target DNA activation, Cas12a can trans-cleavage ssDNA G-quadruplex. TMB/H2O2 and Hemin cannot be catalyzed by cleavaged G-DNA to produce green color products. This protocol is useful for the detection of ASFV and PCV2 with high sensitivity. This method can enable the development of visual and label-free ASFV and PCV2 detection and can be carried out in the field without relying on instruments or power. This method can complete nucleic acid detection at 37 °C without using other instruments or energy. Our research has expanded the application of Cas12a and laid the foundation for the field's rapid detection of viral nucleic acid in future.</p

Novel Reversible Mechanochromic Elastomer with High Sensitivity: Bond Scission and Bending-Induced Multicolor Switching

Although the rational designed mechanochromic polymer (MCP) materials have evoked major interest and experienced significant progress recently, it is still a great challenge to develop a facile and effective strategy for preparation of reversible broad-spectrum MCPs with a combination of wide-range color switch ability and high sensitivity, which thus make it possible to mimic gorgeous color change as in nature. Herein, we designed and synthesized a novel rhodamine-based mechanochromic elastomer. Our results demonstrated that the elastomer exhibited very promising and unique properties. Three primary fluorescence colors were presented during continuous uniaxial extension and relaxing process, and reversible broad-spectrum fluorescence color change could be achieved consequently. The fluorescence quantum yield of the opened zwitterion of this new mechanophore was as high as 0.67. In addition, the elastomer showed very high sensitivity to stress with a detectable activation strain of ∼0.24, which was much smaller than those reported in the previous literature reports. Meantime, the easy-to-obtain material, facile preparation, and good mechanical property also made it suitable for potential practical applications