Preparation of aptamer-bound polyamine affinity monolithic column via a facile triazine-bridged strategy and application to on-column specific discrimination of ochratoxin A.

Developing a high-performance modification protocol is critical for efficiently fabricating affinity monolith. Herein, by using 2,4,6-trichloro-1,3,5-triazine as the linker, a simple triazine-bridged approach was proposed for efficiently fabricating aptamer-grafted polyhedral oligomeric silsesquioxane-polyethyleneimine affinity monolith with high specificity toward ochratoxin A. Experimental parameters, column characteristics and specificity performances of the resultant affinity monolith were investigated in detail. Under the optimal conditions, 2,4,6-trichloro-1,3,5-triazine was rapidly grafted on the polyamine matrix, and effectively applied to the subsequent bridge linkage of aptamers. It was simple and effective, which resulted in a significant decrease of modification time, excellent properties including the high coverage density of aptamer up to 1799 pmol/μL and sensitive detection of ochratoxin A as low as 10 pg/mL in beer samples. This protocol provides a facile approach for fabricating aptamer-grafted polyamine affinity monoliths with highly selective discrimination performance.