[13]Shang LR, Fu FF, Cheng Y, Wang H, Liu YX, Zhao YJ*, Gu ZZ*. Photonic Crystal Microbubbles as Suspension Barcodes.Journal of the American Chemical Society .2015, 137, 15533-15539. See also http://www.http://pubs.acs.org/doi/full/10.1021/jacs.5b10612/