Construction of surface molecularly imprinted photonic hydrogel sensors with high sensitivity

In comparison with molecularly imprinted photonic hydrogel (MIPH) with specific molecular recognition sites inside matrix, surface molecularly imprinted photonic hydrogel (S-MIPH) is more competitive as a molecular sensor due to presence of molecular recognition sites distributed on surface of hydrogel wall. Nevertheless, the construction of S-MIPH sensors is still challenging owing to the absence of interaction between traditional colloids and imprinted molecules. Here we report the construction of S-MIPH sensors by using poly (styrene-acrylic acid) colloids with abundant carboxyl group that are capable of binding imprinted molecules readily through hydrogen interaction. Benefit from this novel motif, S-MIPH sensors can be readily constructed by self-assembly of poly (styrene-acrylic acid) colloids binding imprinted molecules, the polymerization of precursor solution, as well as finally removal of colloids and imprinted molecules. The self-assembly of poly (styrene-acrylic acid) colloids binding imprinted molecules was investigated in detail. The as-prepared sensor delivers high sensitivity (as low as 10 −9 mol L −1 ), rapid response speed (< 60 s), and good selectivity owing to the 3D macroporous structure and specific molecular recognition sites that are well distributed on surface of hydrogel wall. Additionally, the developed sensors show good sensing performance even in commercial milk, showing great potential for real application. The self-assembly of poly (styrene-acrylic acid) colloids binding imprinted molecules into colloidal crystal was investigated in detail, and surface molecularly imprinted photonic hydrogel sensors with 3D macroporous structure and surface specific molecular recognition nanocavities were successfully constructed.