Fig. 4: Photopatterning of chiral PDA into various 2D patterns.

a Tai-Chi patterns where the red and blue regions filled with left-handed and right-handed PDA when stained with a small chiral alcohol. The filling colors are switched for the two enantiomers of the alcohol. Scale bars, 1 cm. b A microarray of chiral PDA patches in 5 µm × 5 µm squares and 2 µm spacing. Scale bars, 5 µm. c A piece of hidden information coded with chirality that can be deciphered with chiral molecules only. Scale bars, 1 cm.