Constructed artificial antibody to in situ detection of ultratrace picric acid derivative with fluorescence-enabled self-reporting

It is a tremendous challenge for the detection of target analyte without self-reporting optical, electronic, and magnetic signal and so on, in situ recognition site. Herein, a strategy for a synthesized artificial antibody (imprinted polymer microspheres, MIPs) microsphere with non-fluorescence tagged recognition site for the detection of ultra trace picric acid derivative with fluorescence-enabled self reporting in solution environments. Picric acid reacted with N, N'-diisopropyl carbodimide to generate the picric acid derivative 1 (PAD1) with bright yellow fluorescence and the picric acid derivative 2 (PAD2) without fluorescence, respectively. The artificial antibody with the performance of selective recognition and sensible detection were synthesized through the copolymerization with reaction of using PAD1 as template, acrylamide as functional monomer, ethylene glycol dimethacrylate as crosslinking agent and azodiisobutyronitrile as initiator in acetonitrile solution. The recognition sites of polymer microspheres eluting imprinted-PAD1 template molecules in microsphere surface have hollow cavities matching the spatial structure of template molecules. The in situ recognition sites of the microspheres were rebounded by trace PAD1 through the concentration difference driving force on the microsphere surface, the PAD1 target molecule with fluorescence- enabled self reporting in situ recognition sites was sensibly detected through the change of fluorescence intensity, thus the as-synthesized imprinted microspheres can efficiently and selectively identify and high sensibly detect the trace PAD1 in the solution environment.