Highly Ordered Assembly of Templates on Molecular Imprinting toward Phosphorylated Compounds for Improved Performance

Molecular imprinting, known as a superior technique for making artificial antibodies, always suffers from template optimization in terms of distribution and orientation for specific recognition of targeted molecules especially in the case of phosphorylated compounds. These phosphate-containing substances, e.g., nuclear acids, protein modification forms, and drug derivatives, are of great importance for biomedical study. To obtain efficient binding performance, we developed a strategy for oriented assembly of the phosphate group by using TiO2 as the surface functionality on the Fe3O4 core, where highly ordered cavities can be obtained as compared to the bare SiO2-based substrate. This oriented assembly of the template enables the improved recognition of phosphorylated compounds through enhanced molecular recognition interactions. It was also demonstrated that excess template molecules could decrease the binding efficiency due to the random distribution and orientation of template molecules without enough available binding sites of TiO2. By using cytidine monophosphate as a proof-of-principle study, the binding capacity of oriented imprinting strategy can increase the binding capacity 5 times than that of SiO2 and 1.5 times that of TiO2 with an excess template. The method was further extended to phosphorylated-drug and also phosphoprotein with high selectivity, excellent enrichment efficiency, adsorption capacity, reproducibility, and excellent stability. We believe this oriented imprinting strategy will have great potential for various biological applications and can also be expended to other imprinting systems.