Detection of p-Nitrophenol Using Molecularly Imprinted Colloidal Array

p-Nitrophenol (p-NP) molecularly imprinted colloidal microspheres were prepared by polymerization of functional monomers (acrylamide, AM) and template of p-NP in poly (methyl methacrylate, PMMA) pre-polymerization solution. Molecularly imprinted colloidal array (MICA) was prepared using the molecularly imprinted colloidal microspheres by self-assembly, and then fixed by an adhesive tape. The MICA on the adhesive tape was easy to handle and had strong stability. The MICA film combines both the high selectivity of molecular imprinting and facility to use of photonic crystal. This material senses p-NP in aqueous solution by shifting reflection wavelength. The adsorption of p-NP into molecularly imprinted colloidal microspheres would swell the microspheres, thus leading to a reflection peak red shift. The reflection peak redshifted nearly 60 nm when the concentration of p-NP increases from 0 mM to 30 mM, while non-imprinted molecularly imprinted colloidal array (NICA) red shifted about 40 nm. The color of MICA changed from red to blue-violet was observed. This method simplifies the preparation of photonic crystal material which is an efficient approach for developing high-performance chemical/biological sensors.