Hydrazone bond-oriented molecularly imprinted nanocomposites for the selective separation of protein via the well-defined recognition sites.

The development of hydrazone bond-oriented epitope imprinting strategy is reported to synthesize the polymeric binders for the selective recognition of a protein-ß2-microglobulin through either its N- or C-terminal epitope. The dynamic reversibility of hydrazone bond facilitated not only the oriented assembly of the template peptide hydrazides onto the substrate but also the efficient removal of them from the imprinted cavities. The well-defined surface imprinted layer was successfully constructed through the precise control over the polymerization of silicate esters. Binding performance of the C-terminal peptide imprinted nanocomposite was significantly improved after tuning the non-covalent interactions using the sequence-matching aromatic co-monomers. The dissociation constant (Kd) between the optimized nanocomposite and epitope peptide was 0.5 µmol L-1. The nanomaterial was utilized for the selective extraction and determination of ß2-microglobulin from human urine by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and HPLC-UV with satisfied recoveries of 93.1-112.3% in a concentration range 1.0-50.0 µg⋅mL-1.

Oriented docking of the template for improved imprinting efficiency toward peptide with modifications.

Molecular imprinting polymers (MIPs) are synthetic receptors as biomimetic materials for various applications ranging from sensing to separation and catalysis. However, currently existing MIPs are stuck to some of the issues including the longer preparation steps and poor performance. In this report, a facile and one-pot strategy by integrating the in-situ growth of magnetic nanoparticles and reversed phase microemulsion oriented molecularly imprinting strategy to develop magnetic molecular imprinted nanocomposites was proposed. Through self-assembling of the template, it brought up highly ordered and uniform arrangement of the imprinting structure, which offered faster adsorption kinetic as adsorption equilibrium was achived within 15 min, higher adsorption capacity (Qmax = 48.78 ± 1.54 µmol/g) and high affinity (Kd = 127.63 ± 9.66 µM) toward paradigm molecule-adenosine monophosphate (AMP) compared to the conventional bulk imprinting. The developed MIPs offered better affinity and superior specificity which allowed the specific enrichment toward targeted phosphorylated peptides from complex samples containing 100-fold more abundant interfering peptides. Interestingly, different types of MIPs can be developed which could targetly enrich the specific phosphorylated peptides for mass spectrometry analysis by simply switching the templates, and this strategy also successfully achieved imprinting of macromolecular peptides. Collectively, the approach showed broad applicability to target specific enrichment from metabolites to phosphorylated peptides and providing an alternative choice for selective recognition and analysis from complex biological systems.