{'fraction_non_alphanumeric': 0.031451612903225803, 'fraction_numerical': 0.008064516129032258, 'mean_word_length': 5.364102564102564, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Visible-light circular dichroism of colourless chiral organic compounds enabled by interfacial charge-transfer transitions.

We report the visible-light circular dichroism (CD) of colourless organic compounds based on interfacial charge-transfer (ICT) transitions with TiO2 nanoparticles. We employed three kinds of colourless chiral compounds, l-ascorbic acid, d-ascorbic acid, and l-noradrenaline. These compounds showed a broad ICT band in the visible region between 400 and 600 nm upon their chemisorption on TiO2 nanoparticles. l-Ascorbic acid and l-noradrenaline adsorbed on the TiO2 nanoparticles showed positive and negative CD signals in the visible region, respectively. d-Ascorbic acid, which is the enantiomer of l-ascorbic acid, exhibited positive CD signals in the visible region, but different g factors (Δε/ε) from those of TiO2-l-ascorbic acid, well reflecting the different chirality of the substituent group. The visible-light CD based on ICT transitions enables selective visible-light CD sensing and imaging of colourless chiral biomolecules even if coexisting with other colourless chiral compounds such as proteins and DNA. Furthermore, the molecular dependence of the g factor allows us to identify chiral molecules.