A novel enrichment imprinted crystalline colloidal array for the ultratrace detection of chloramphenicol

A novel photonic crystal (PC) for the enrichment and detection of trace chloramphenicol (Cm) was constructed based on the combination of the imprinted crystalline colloidal array (ICCA) and the enrichment effect induced by wettability differences. The enrichment ICCA (E-ICCA) material had a highly ordered opal structure consisted of hydrophilic molecular imprinting polymer (MIP) spheres and the surrounding hydrophobic polydimethylsiloxane (PDMS) matrix, thus showing the desired structural color but also possessing the large hydrophilicity/hydrophobicity (HP) interaction area to enable efficient enrichment of the target Cm molecules from a highly dilute solution to the MIP sphere surface. The sensitive Cm recognition of MIP spheres finally caused the reduced reflection intensity and a red shift of the material due to changes of the periodic structure. Using this sensing platform, the highly sensitive detection of Cm (as low as 1.5×10^-9M) with high selectivity was achieved without using label techniques and expensive detection instruments. Furthermore, the developed method successfully used to screen Cm in drinking water samples. Therefore, this approach is extensible to the construction of many sensor systems for the sensitive detection of drugs, diseases, and pollutions of food and the environment.