Direct nanolayer preparation of molecularly imprinted polymers immobilized on multiwalled carbon nanotubes as a surface-recognition sites and their characterization

Preparation and evaluation of photo-responsive hollow SnO2 molecularly imprinted polymers for the selective recognition of kaempferol

Novel photo-responsive hollow structured molecularly imprinted polymers (PHMIPs) were developed as a selective sorbent to recognize and separate analytes in complex samples. The PHMIPs were prepared using kaempferol (KAE) as the template, 4-[(4-methacryloyloxy) phenylazo] benzenesulfonic acid as a photo-responsive functional monomer, and hollow SnO₂ (Ho-SnO₂) as the support via free radical polymerization. The structure and physical properties of the developed polymers were characterized using different nano structural techniques and spectroscopy. Under alternating irradiation at 365 and 440 nm, the PHMIPs could release and uptake KAE, indicating that the template molecules can be easily bound to recognition sites and released back into solution. From adsorption experiments, the binding properties were evaluated, and the maximal adsorption capacity of the PHMIPs was 11.04 mg g^-1. Furthermore, the developed PHMIPs showed high selectivity towards KAE compared to other compounds. Subsequently, the materials were successfully applied to the photo-controlled extraction of KAE from sea buckthorn leaves. The recoveries for KAE were higher than 90% and relative standard deviation values were between 1.81% and 2.53%, indicating the potential of the developed materials for use in extracting KAE from complex samples.

Application of molecularly imprinted polymers in the anti-doping field: sample purification and compound analysis

The problem posed by anti-doping requirements is one of the great analytical challenges; multiple compound detection at low ng ml-1 levels from complex samples, with requirements for exceptional confidence in results. This review surveys the design, synthesis and application of molecularly imprinted polymers (MIPs) in this field, focusing on the templating of androgenous anabolic steroids (AASs), as the most commonly abused substances, but also other WADA prohibited substances. Commentary on the application of these materials in detection, clean-up and sensing is offered, alongside views on the future of imprinting in this field.

Rational design and tailoring of imprinted polymeric enantioselective sensor layered on multiwalled carbon nanotubes for the chiral recognition of d-mandelic acid

Attempts have been made to investigate the feasibility of fabricating an enantiomeric sensor for the specific detection of d-mandelic acid layered on vinyl-MWCNT using molecular imprinting technology.

Creation of Hollow Calcite Single Crystals with CQDs: Synthesis, Characterization, and Fast and Efficient Decontamination of Cd(II)

In this work, carbon quantum dots were first prepared through one-pot hydrothermal route of the propyl aldehyde and sodium hydroxide via an aldol condensation reaction, and a novel solid-phase extraction adsorbent of hollow calcite single crystals was prepared via the precipitation of metal nitrates by the CO₂ diffusion method in the presence of CQDs and further applied for excessive Cd(II) ions removal from water. The spectra and morphologies of the etched calcite were investigated by X-ray diffraction, Fourier transform infrared spectrometry, Scanning electron microscope, and Transmission electron microscopy. The results show that the CQDs etching technique successfully furnish a strategy for manufacturing interface defects onto the calcite crystal. Bath studies were done to evaluate the effects of the major parameters onto Cd(II) adsorption by the etched calcite, such as pH, contact time, and initial Cd(II) concentration. The Cd(II) adsorption onto the new adsorbent could reach a maximum adsorption amount of 66.68 mg/g at 120 min due to the abundant exterior adsorption sites on the adsorbent. The adsorption kinetics and adsorption isotherms of Cd(II) on the etched calcite were also investigated. The experimental datum showed that the adsorption kinetics and isotherms of Cd(II) on the etched calcite were well-fitted by the pseudo-second-order kinetic model and the Freundlich isotherm model respectively. The adsorption mechanisms could be primarily explained as the formation of Cd(OH)₂ and Ca_xCd_1-xCO₃ solid solution on the adsorbent surface with the help of X-ray photoelectron spectroscopy.

Green silver nanoparticles as a multifunctional sensor for toxic Cd(ii) ions

Silver nanoparticles (AgNPs) were synthesized using Allium sativum (AS) extract. The AgNP-AS was able to detect Cd(ii) ions with various techniques such as optical, fluorescence and electrochemical sensing. The limit of detection was found to be 0.277 μM. Silver nanoparticles were able to quantify Cd(ii) ions from environmental samples. The antibacterial activity of AgNP-AS was explored towards waterborne bacteria.

Surface molecularly imprinted polymers grafted on ordered mesoporous carbon nanospheres for fuel desulfurization

By adopting OMCNS as a carrier, the corresponding desulfurization adsorbent SMIP/OMCNS possesses excellent adsorption capacity and selectivity towards DBT.