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Graphical abstract Highlights • Molecularly imprinted mesoporous silica microspheres for the sensing of sparfloxacin. • The microspheres showed highly ordered, periodic hexagonal mesoporous structure. • A level of analytical performance was achieved for sensing of sparfloxacin. Abstract This paper describes an alternative strategy for the preparation of highly ordered molecularly imprinted mesoporous silica microspheres (MIMSM) for the selective fluorescence sensing of sparfloxacin in biological samples. We designed and synthesized a new functional monomer through the thiol-ene click chemistry reaction of 3-(methacryloyloxy) propyltrimethoxysilane and 3-mercaptopropionic acid. Sparfloxacin was selected as a template, and Mn-doped ZnS quantum dots served as the signal transducing element. This one-pot strategy was used to fabricate the MIMSM. Fourier transform infrared spectroscopy demonstrated successful embedding of a functional monomer in the mesoporous silica microspheres, and the highly ordered, periodic hexagonal mesoporous structure of MIMSM was confirmed with small angle X-ray diffraction, transmission electron microscopy, and N 2 adsorption-desorption measurements. The fluorescence intensity of the MIMSM had linear correlation with 0.05–2.0 μg/mL sparfloxacin. There was a rapid response time and excellent selectivity for structural analogues. Under optimal conditions, the limit of detection was 0.012 μg/mL for sparfloxacin. This method was then used with serum samples to achieve recoveries of 88.8–102%. [ABSTRACT FROM AUTHOR]

This paper describes an alternative strategy for fabricating a fluorescent aptamer functionalized molecularly imprinted polymer (MIP) for highly specific sensing of kanamycin. The technique provides surface imprinting in aqueous solutions using CdSe quantum dots as supports, thiols modified aptamer and methacrylic acid as functional monomers, and kanamycin as a template. The MIP would function utilizing double recognition of the aptamer and imprinted cavities for fluorescent sensing of kanamycin. The “thiol-ene” click reaction was utilized to fix the aptamer into polymer matrix, and the click chemistry used was highly efficient under mild condition and environmentally friendly. Experimental results indicated that there was a synergistic interaction between the aptamer and MAA, which improved the recognition ability of MIP toward kanamycin. The MIP showed an imprinting factor of 3.51 for kanamycin, excellent analog selectivity, and strong resistance toward ions interference. The fluorescence intensity of the MIP enhanced gradually with increase in the concentration of kanamycin, and exhibited good linear correlation within the concentration of 0.05–10.0 μg/mL with a detection limit of 0.013 μg/mL. This fluorescent MIP was further applied to quickly, sensitively and simply sensing of kanamycin in food, water and biological samples which yielded satisfied results. [ABSTRACT FROM AUTHOR]

Highlights: [•] Composite network and microporous P2VP/Cu(II) structures were fabricated. [•] Composite nano-shuttle and microbelt of P2VP/Cu(OH)2 were obtained. [•] These nanostructures were fabricated at the liquid/liquid interface. [•] Adsorption, hydrolysis and self-assembly processes were involved in the fabrication. [•] The two kinds of nanostructures exhibited different catalytic properties. [Copyright &y& Elsevier]

Abstract: Free-standing thin films of poly(2-vinylpyridine) (P2VP) doped with platinum complex ions were fabricated at the planar aqueous solution of H2PtCl6/chloroform solution of P2VP interface. The formation of the free-standing thin films was attributed to the adsorption and combination of the polymer molecules and the complex ions at the interface, and self-assembly of the composites. The films were composed of thin layers decorated with separated and conglutinated microcapsules. After treatment with KBH4 aqueous solution, the platinum complex ions incorporated in the polymer matrices transformed to platinum nanoparticles with the mean size of 2.2nm, which was confirmed by transmission electron microscopic investigations and X-ray photoelectron spectroscopic (XPS) analysis of the samples. Both the contents of the platinum element in the untreated and treated composite films estimated based on the thermagravimetric analysis (TGA) were close to each other, indicating no loss of platinum during the treatment process. The catalytic activity of the composite films was evaluated by using the reduction of 4-nitrophenol by KBH4 in aqueous solutions. The results indicated that the composite films have high and durable catalytic activity. [Copyright &y& Elsevier]

• A novel MIP/perovskite CsPbBr 3 QDs fluorescence sensor for phoxim detection. • A siloxane functional monomer with two kinds of functional groups has been synthesized. • The MIP/QDs were synthesized by slowly hydrolyzing the organosilicon monomers in situ. • The QDs were encapsulated in an imprinted silica matrix, which improved the stability of the QDs. In spite of the high-brightness of perovskite quantum dots (QDs), their instability and sensitive to oxygen and moisture are still major challenges that obstruct their analytical applications. This work demonstrates the fabrication and application of perovskite CsPbBr 3 QDs embedded in a molecularly imprinted polymer (MIP) for specific and sensitive detection of phoxim in real samples. CsPbBr3 QDs were obtained via a simple and convenient hot injection method. Based on the chemical structure of phoxim, we designed and synthesized a siloxane functional monomer with multiple functional groups to allow various types of interactions with phoxim. Next, the MIP/QDs composites were synthesized by slowly hydrolyzing the organosilicon monomers in situ. The obtained MIP/QDs composites possessed excellent selectivity for phoxim, and the imprinting factor of the optimized MIP/QDs was 3.27. Compared with previous studies regarding the detection of organophosphorus pesticides, the MIP/QDs fluorescence sensor exhibited high sensitivity and specificity. Under optimal conditions, the fluorescence quenching of the MIP/QDs had a good linear correlation for phoxim in the concentration range of 5–100 ng/mL, and with a limit of detection of 1.45 ng/mL. Finally, the method was used for the detection of phoxim in potato and soil samples, achieving recoveries of 86.8–98.2%. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel hybrid aptamer–MIP/QDs fluorescent sensor for specific recognition to Cyt C has been synthesized. • Double recognition of aptamer–MIP/QDs to Cyt C is originated from imprinted cavity and aptamer. • Double recognition enhances affinity to Cyt C • Aptamer–MIP/QDs selectively and sensitively recognized Cyt C in biosamples. Abstract This work demonstrates a strategy of double recognition hybrid aptamer–molecular imprinted polymer/quantum dots (apt–MIP/QDs) fluorescent sensor for specific recognition of target protein. We selected vinyl modified Mn–doped ZnS QDs as signal source and support. Instead of relying on single source of weak interaction between protein and small molecule monomer, thiol terminated aptamers were used as specific functional monomers to obtain apt–MIP on the surface of QDs. The double recognition was based on aptamer and imprinted cavity to overcome the challenges of protein imprinting. The synergistic effect of the aptamer and MAA contributed for highly specific recognition ability of the apt–MIP/QDs sensor toward Cyt C. The imprinting factor and the selectivity factor values of the hybrid apt–MIP/QDs sensor were 3.17 and 8.33, respectively. This composite sensor showed an excellent linear correlation for Cyt C in the concentration range of 0.20–2.00 μM. The detection limit for Cyt C was 0.054 μM A sensitive, rapid and convenient recognition system for Cyt C in biological samples was developed. The recoveries were between 94.2% and 102.5% for urine and serum samples. [ABSTRACT FROM AUTHOR]

Chlorides are usually neglected during heavy metal remediation. In this study, rice husk (RB) and sludge (SB) biochars were applied to investigate the influences of Cl on Pb remediation. Cl modification significantly increased Pb removal (RB: 336.84% and SB: 404.56%) as it increased the surface area, micropore volume and P release of the two biochars. The adsorption kinetics showed that Cl modification improved the coexistence of physical adsorption and chemical precipitation on biochar. However, the adsorption correlation of physical factors (BET, R = 0.299–0.502) to Pb is significantly lower than that of chemical factors (P and Cl, R = 0.875–0.982). Meanwhile, the contributions of specific surface area (R = 0.299–0.502) and micropore volume (R = 0.471–0.693) to Pb adsorption were significantly lower than that of Cl (R = 0.944–0.953), based on redundancy analysis. The loading degree of Cl (RB 79.1%, SB: 77.8%) on modified biochar was confirmed as the primary factor in stabilization of Pb. In addition, the pH had limited influences on Pb adsorption (P value = 0.524). Abundant C–Cl functional groups appeared on the surface of the two biochars after Cl loading according to ATR-IR and XPS analysis. Then, Pb2+ diffused into the interior of biochars via mesopores and formed C–Cl–Pb–P complexes. The active Pb (water soluble and exchangeable) could be finally transformed into stable fraction (acidic and non-bioavailable), i.e., pyromorphite [Pb 5 (PO 4) 3 Cl] based on both experimental and GWB modeling results. In particular, the adsorption/stabilization of Pb was more favorable by the biochar with <15 μm particles. The contrasts between RB and SB can be attributed to that low-temperature pyrolysis of RB (450 °C) has a large amount of CO 3 2− that limits formation of pyromorphite. This study hence proposed that Cl loading technology can substantially improve the Pb remediation effect of biochar. [Display omitted] • HCl leaching improve micropore volume and specific surface area of biochar. • Cl addition improves the formation of stable pyromorphite. • H+ has limited contribution to the adsorption of Pb by biochar. • Cl modification time is critical for the abundance of surficial C–Cl groups. • Chemical precipitation is main mechanism of Cl-biochar for Pb remediation. [ABSTRACT FROM AUTHOR]

Carbonate in soil from karst region is a substantial carbon sink on Earth. Many karst regions are covered by P-deficient soil. This study evaluated the influences of phosphate addition on fungal weathering (by typical phosphate-solubilizing fungus Aspergillus niger) of carbonate in the soil with red color from karst region. Two weathering pathways were recognized, i.e., biochemical and biomechanical deterioration. The biochemical pathway was performed by dissolving carbonate via secreting organic acids. Meanwhile, the dominant organic acid, i.e., oxalic acid, induced the formation of calcium oxalate, which prevented the loss of Ca2+ cations. It was estimated that the ideal carbonate solubilization driven by geological fluorapatite and fungal weathering is up to 3.3% per year, based on the equation of 12 × (R Base + R PSF) × m × (A real /A PSF). Moreover, fungal weathering of carbonate is very sensitive to the solubility of phosphates. Phosphates supply essential P source for the fungal growth and subsequently raise water-soluble P content in the soil. The addition of bioapatite (a variety of natural apatite with relatively high solubility) elevated the value to 4.6% (a ~ 40% enhancement compared with FAp). This research hence elucidated the tight correlation between carbonate weathering and P supply. Inorganic C release driven by P availability and microbial weathering should be addressed in karst region. Unlabelled Image • A. niger can release abundant oxalic acids to prevent Ca2+ loss via the formation of Ca-oxalate. • Phosphate addition significantly enhances (up to ~5%) the fungal weathering rate of carbonate in soil. • The low solubility of FAp is the major drawback of P supply and bioweathering of minerals. • Both of biochemical and biomechanical deterioration contributes to fungal weathering of carbonate rocks. • C flux driven by P availability and microbial weathering should be addressed in karst region. [ABSTRACT FROM AUTHOR]