Single crystallinity of the as-grown PdGa crystals was first analyzed using a white beam backscattering Laue X-ray diffraction at room temperature. Both the PdGa crystal batches show sharp and well-defined Laue spots, which can be indexed with a single pattern (Fig. and). This illustrates the excellent quality of the grown crystals. Then rigorous single-crystal X-ray diffraction was performed to analyze the structural chirality, Flack's parameter, etc. as explained in previous references . The identified enantiomers of form-A and form-B of the PdGa crystals are as defined in Ref. . Two of the crystals obtained from the same batch were selected and served as the working electrode for DOPA enantiomeric recognition. The scanning electron microscope (SEM) images recorded with secondary and backscattered electrons suggest the high homogeneity of the two crystals (inset Fig. , Fig. ).