Abstract: The incorporation of molecularly imprinted materials into photonic crystals presents an ideal sensing platform on which analyte recognition and analyte-dependent transduction methodology could be realized simultaneously. Here, a colorimetric molecularly imprinted photonic polymer (MIPP) sensor has been developed for the sensitive and selective chiral recognition of amino acids. The sensor was fabricated by infiltrating a polystyrene photonic crystal template with precursor and imprinting molecules, followed by a thermal polymerization. After removal of templates, the resulted MIPP consists of a three-dimensional, highly-ordered and interconnected macroporous array. The amino acids recognition events thus could be directly transferred into visible color changes and readable optical signals through the diffraction peak shifts of MIPP. A function relationship was found between the diffraction peak shift and the concentration of l-pyroglutamic acid (l-Pga) in the range of 0.01 - 0.50 mM at pH 4, and a linear relationship with a slope of 278 nm/mM was found when the concentration of l-Pga was lower than 0.20 mM. The chiral recognition process accompanying with a gradual color change of MIPP can be easily visualized by the naked eye. The developed method has been applied to detect l-Pga in monosodium glutamate samples
Template and target information: l-pyroglutamic acid, l-Pga
Author keywords: Pyroglutamic acid, chiral recognition, Photonic crystal, molecular imprinting technique