An aptamer@AuNP-modified POSS–polyethylenimine hybrid affinity monolith with a high aptamer coverage density for sensitive and selective recognition of ochratoxin A

Abstract

A new POSS-based aptamer affinity hybrid monolith, Apt@AuNPs@POSS–PEI, with a well-controlled 3D skeletal structure and a high aptamer coverage density of up to 1413 pmol μL−1 has been facilely fabricated.

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

“…Attributing to highly efficient grafting reaction of TCT, a good level of the aptamer capacity has been detected according to the equation (1) in ESI and gained at 1799 ± 60 pmol/μL (RSD = 3.3%, n = 3, in Supporting Information Table S3). It was high enough and better than that of amine‐activated hybrid affinity monoliths (∼568 pmol/μL) prepared with glutaraldehyde and Apt@AuNPs modified monoliths (277–342, 1413 pmol/μL) , respectively. As seen from Supporting Information Figure S4, the dynamic binding capacity of OTA on the resultant monolith was gained at 15.9 ng/cm 3 (1.25 ng/cm), which was similar to that of Apt@AuNPs@POSS‐PEI affinity monoliths (15.1 ng/cm 3 , 1.19 ng/cm) , and better than that of other amine‐activated siloxane‐based hybrid affinity monoliths (9.1 ng/cm 3 , 0.71 ng/cm) reported previously .…”

“…POSS‐PEI parent matrix was prepared according to the references and as shown in Supporting Information Table S1. Apt‐TCT@POSS‐PEI affinity monolith was prepared as Figure .…”

“…According to the references , the discrimination of OTA with Apt‐TCT@POSS‐PEI affinity monolith was measured by online coupling with HPLC system. As shown in Supporting Information Figure S1 in Electronic Supporting Information (ESI), the sample loading and elution procedures were carried out with a continuous adsorption/desorption mode by switching mobile phase.…”

“…The coverage density of aptamers still stayed at a level less than 342 pmol/μL. Recently, by using polyhedral oligomeric silsesquioxane‐polyethyleneimine (POSS‐PEI) monolith as the support matrix , a high coverage density of aptamer up to 1413 pmol/μL was achieved . However, it was notable that, the grafting of AuNPs on the surface of support materials was preceded within the capillary, and affected the permeability of monolithic column seriously.…”

“…Herein, by using TCT as the active linker, a highly efficient triazine‐bridged grafting of aptamer on the stereoscopic framework of POSS‐PEI matrix with massive amino groups to prepare affinity monolith was proposed and shown in Figure . An interesting functional interface with plenty of primary and secondary amines was presented in the POSS‐PEI support matrix , which could provide massive active sites for the further immobilization of aptamer when reacted with TCT. In this work, via the bridge of TCT, the aptamer‐modified POSS‐PEI affinity monolith (Apt‐TCT@POSS‐PEI) was achieved.…”