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Covalent organic frameworks (COFs) have attracted extensive attention as promising materials for the elimination of various organic pollutants due to their high surface area, inherent porosity and tailorable functionality. However, powdery COFs are difficult to separate and reuse, which greatly limits their practical applications. Herein, a β-cyclodextrin functionalized imine COF (β-CD-COF) aerogel with good crystallinity and chemical stability was synthesized by the Schiff base reaction using a one-pot method for efficient removal of anionic and cationic dyes from water. The prepared β-CD-COF aerogel has a macroscopic three-dimensional bulk and hierarchical porous structure, which is conducive to adsorption and recovery, and it not only showed high adsorption capacity and fast binding kinetics for single anionic and cationic dyes (3403.91 mg g−1 for methyl orange (MO) and 2199.37 mg g−1 for methylene blue (MB)), but also exhibited outstanding simultaneous adsorption capacity in different binary and ternary pollutant systems. Additionally, the β-CD-COF aerogel showed good reusability for the co-adsorption of MO and MB. These results demonstrate the great potential of β-CD-COF aerogels for the simultaneous removal of anionic and cationic dyes in environmental applications. [ABSTRACT FROM AUTHOR]

Highly selective and highly efficient identification of large viruses has been a major obstacle in the field of virus detection. In this work, a novel sandwich resonance light scattering sensor was designed based on molecularly imprinted polymers (MIPs) and aptamers for the first time. One of the recognition probes was obtained by molecular imprinting using environmentally friendly carbon spheres as carriers and the other by modification of the aptamer that can specifically recognize hepatitis B virus (HBV) on the surface of silicon spheres. In the presence of both probes, an MIP-HBV-aptamer sandwich structure was formed continuously in the system with the increase in HBV concentration, resulting in a strong resonance light scattering response. Finally, satisfactory selectivity and sensitivity were obtained, and the imprinting factor was as high as 7.56, which was higher than that reported in previous works of viral molecular imprinting sensor. In addition, it is of great significance to solve the problem of insufficient selectivity of traditional detection methods for macromolecular targets. [ABSTRACT FROM AUTHOR]

Because rapid, convenient, and selective methods for HIV detection are urgently needed, herein, a simple label-free and enzyme-free strategy is constructed for sensitive fluorescence detection of HIV DNA using the fluorescent intercalating dye thioflavin T (THT) as the detection signal source. This strategy utilizes a hairpin DNA sequence (H1) and two assistant strands. H1 is wisely designed with a G-quadruplex sequence in the stem. Target DNA, when present in solution, will hybridize with H1 to form H1/target duplexes and release the G-quadruplexes. Additionally, the assistant probes hybridize with the unfolded H1 to form a stable DNA double strand, resulting in the displacement of the target to participate in another similar reaction cycle. Consequently, many G-quadruplex structures are generated, leading to a significantly amplified fluorescence signal of THT. The linear range is from 0.1 nM to 50.0 nM with a limit of detection of 13 pM. Results can be achieved within 40 min, because the cyclic amplification involves only one DNA hairpin and two auxiliary chains. Furthermore, this platform exhibited good selectivity with one base mismatch or other DNA sequences. This strategy could be used as a simple, sensitive, and selective tool to detect other DNA biomarkers. [ABSTRACT FROM AUTHOR]

This study demonstrated fluorescent detection of Japanese encephalitis virus (JEV) by surface molecularly imprinted technique. After dansyl chloride (DNS-Cl) was immobilized on silica microspheres (SiMP) with JEV as the template, (3-aminopropyl)triethoxysilane (APTES) as the monomer and tetraethyl orthosilicate (TEOS) as the cross-linker was mixed with SiMP, and the polymerization was performed in mild condition. After polymerization, templates were removed to obtain JEV-imprinted polymers (JEV-MIPs). The obtained JEV-MIPs can selectively recognize JEV in the presence of Hepatitis A virus (HAV), Simian virus 40 (SV40) and Rabies virus (RV), and also sensitively detect JEV with a picomolar detection limit. [ABSTRACT FROM AUTHOR]

Because rapid, convenient, and selective methods for HIV detection are urgently needed, herein, a simple label-free and enzyme-free strategy is constructed for sensitive fluorescence detection of HIV DNA using the fluorescent intercalating dye thioflavin T (THT) as the detection signal source. This strategy utilizes a hairpin DNA sequence (H1) and two assistant strands. H1 is wisely designed with a G-quadruplex sequence in the stem. Target DNA, when present in solution, will hybridize with H1 to form H1/target duplexes and release the G-quadruplexes. Additionally, the assistant probes hybridize with the unfolded H1 to form a stable DNA double strand, resulting in the displacement of the target to participate in another similar reaction cycle. Consequently, many G-quadruplex structures are generated, leading to a significantly amplified fluorescence signal of THT. The linear range is from 0.1 nM to 50.0 nM with a limit of detection of 13 pM. Results can be achieved within 40 min, because the cyclic amplification involves only one DNA hairpin and two auxiliary chains. Furthermore, this platform exhibited good selectivity with one base mismatch or other DNA sequences. This strategy could be used as a simple, sensitive, and selective tool to detect other DNA biomarkers.