Encoded carriers with a polydimethylsiloxane (PDMS)/photonic crystal/PDMS sandwich structure were fabricated, which could be used for multiplex bioassay. Photonic crystal film was derived by self-assembling monodisperse polystyrene nanoparticles. Detection of three kinds of genes of E. coli was demonstrated with the use of the carriers. These encoded carriers were firstly immobilized with different nucleic acid probes. Then the nucleic acid probes on the carriers were hybridized in the buffer containing target molecules tagged with fluorescent molecules. After hybridization the target molecules were detected by fluorescence and the codes of the carriers were identified by the reflection spectra. Experimental results showed that PDMS/photonic crystal/PDMS sandwich structure was a good approach for the construction of the suspended carriers.

Key words: photonic crystal film, nucleic acid detection, encoded carrier