Hybrid hydrogel microspheres loading single-hole hollow imprinted particles for fast and selective uptake of 2′-deoxyadenosine

A new surface molecularly imprinted polyacrylamide nanoprobe for trace Cr(VI) with RRS technique

This article was used potassium dichromate as the template molecule, silver nanoclusters as the nano matrix, acrylamide as the monomer, ethylene glycol dimethacrylate (EGDMA) as the crosslinking agent, and azodiisobutyronitrile (AIBN) as the initiator to prepare a new silver nanocluster surface MIP (AgNCs@MIP) nanoprobe for chromate. Upon addition of Cr(VI), it selectively adsorbs on the surface of AgNCs@MIP nanoprobes. The dichromate ion absorption peak at 350 nm overlaps with the AgNCs@MIP RRS peak at 370 nm, resulting in strong RRS energy transfer (RRS-ET) and a decrease in the RRS intensity. The decreased RRS intensity is directly proportional to the concentration of dichromate ions in the range of 0.0025-0.015 µmol/L, with a detection limit of 0.8 nmol/L. Therefore, a simple, fast, sensitive and selective RRS method for the determination of trace Cr(VI) in mineral water has been established, with a relative standard deviation of 9.2-9.8 % and recovery of 95.20 %-103.60 %.

The construction of highly selective surface molecularly imprinted polymers based on Cu(II) coordination for the detection of bisphenol A

Herein, we designed and constructed a highly selective MIPs for bisphenol A (BPA) named Cu-MIPs@CS based on Cu(II) coordination. The synthesis of Cu-MIPs@CS employed a dummy template strategy and surface imprinting technology, with chitosan (CS) as the substrate linked to imprinted layers via Cu2+ bridging. 4-vinylpyridine acted as the functional monomer, capable of forming a complex with the template ketoprofen, while ethylene glycol dimethacrylate served as the cross linker. Cu-MIPs@CS exhibited a significantly enhanced imprinting factor of 14.78 for BPA, which was approximately 6.6 times higher than that of imprinted materials without Cu2+ (MIPs@CS). Cu-MIPs@CS exhibited a selective factor of 12.74 towards resorcinol, which possessed identical functional groups but a smaller size than BPA, representing an enhancement of selectivity by 12.25-fold compared to MIPs@CS. More importantly, Cu-MIPs@CS exhibited a superior discrimination ability between BPA and its structural analogue, diphenolic acid, with an excellent selective factor of 2.93, highlighting its significance in distinguish the structural analogue of BPA. In contrast, MIPs@CS lack sufficient selectivity to differentiate between them. Through exploration of adsorption mechanism of Cu-MIPs@CS, it was demonstrated that the incorporation of Cu2+ significantly reduced nonspecific adsorption, but also facilitated the creation of more selective imprinted cavities by introducing metal coordination, thereby notably enhancing the selectivity of Cu-MIPs@CS. Finally, the developed Cu-MIPs@CS were applied as the solid phase extraction adsorbent and combined with HPLC-DAD detection to establish an analytical method towards BPA in drinking water samples. The limit of detection of the method was 0.14 μg L-1 and recoveries ranged from 95.6 % to 101 %. This work provided broad prospects for construction of highly selective MIPs and accurate quantification of trace amounts of BPA.

Nucleoside Analogs: A Review of Its Source and Separation Processes

Nucleoside analogs play a crucial role in the production of high-value antitumor and antimicrobial drugs. Currently, nucleoside analogs are mainly obtained through nucleic acid degradation, chemical synthesis, and biotransformation. However, these methods face several challenges, such as low concentration of the main product, the presence of complex matrices, and the generation of numerous by-products that significantly limit the development of new drugs and their pharmacological studies. Therefore, this work aims to summarize the universal separation methods of nucleoside analogs, including crystallization, high-performance liquid chromatography (HPLC), column chromatography, solvent extraction, and adsorption. The review also explores the application of molecular imprinting techniques (MITs) in enhancing the identification of the separation process. It compares existing studies reported on adsorbents of molecularly imprinted polymers (MIPs) for the separation of nucleoside analogs. The development of new methods for selective separation and purification of nucleosides is vital to improving the efficiency and quality of nucleoside production. It enables us to obtain nucleoside products that are essential for the development of antitumor and antiviral drugs. Additionally, these methods possess immense potential in the prevention and control of serious diseases, offering significant economic, social, and scientific benefits to the fields of environment, biomedical research, and clinical therapeutics.

Composite Hydrogel Microspheres Encapsulating Hollow Mesoporous Imprinted Nanoparticles for Selective Capture and Separation of 2′-Deoxyadenosine

Hollow mesoporous silica nanoparticles have been widely applied as a carrier material in the molecular imprinting process because of their excellent properties, with high specific surface area and well-defined active centers. However, these kinds of materials face the inevitable problem that they have low mass transfer efficiency and cannot be conveniently recycled. In order to solve this problem, this work has developed a composite hydrogel microsphere (MMHSG) encapsulated with hollow mesoporous imprinted nanoparticles for the selective extraction of 2’-deoxyadenosine (dA). Subsequently, the hollow mesoporous imprinted polymers using dA as template molecule and synthesized 5-(2-carbomethoxyvinyl)-2′-deoxyuridine (AcrU) as functional monomer were encapsulated in hydrogel. MMHSG displayed good performance in specifically recognizing and quickly separating dA, whereas no imprinting effect was observed among 2′-deoxyguanosine (dG), deoxycytidine (dC), or 5′-monophosphate disodium salt (AMP). Moreover, the adsorption of dA by MMHSG followed chemisorption and could reach adsorption equilibrium within 60 min; the saturation adsorption capacity was 20.22 μmol·g−1. The introduction of AcrU could improve selectivity through base complementary pairing to greatly increase the imprinting factor to 3.79. Therefore, this was a successful attempt to combine a hydrogel with hollow mesoporous silica nanoparticles and molecularly imprinted material.