Stimuli-responsive fluorophores with aggregation-induced emission: implication for dual-channel optical data storage

For optical data storage (ODSes), fluorescence may be an ideal computer-readable signal on account of its scalability, correction capability, and potentially enhanced capacity. In this study, we report the synthesis and photoluminescence (PL) behaviour of a class of fluorophores with electron donor and acceptor units. They exhibit AIE properties with long-wavelength emission colour. Owing to the reactive electron withdrawing group, their emission spectra have shown either "on-off'' switching or a remarkable blue-shift upon alkali treatment. The changes in their fluorescence are due to TICT-LE transition as confirmed by their absorption spectra and DFT calculation. The fluorescent response can be recovered or not, depending on the chemical stimulant used for encoding. Based on the stimuli-responsive nature of the fluorophores, we have further developed both rewritable and write-once read-many (WORM) ODSes with single or dual-channel outputs. "0'' and "1'' state of the encoded binary data, corresponding to the TICT and LE emission, can be read easily using a spectrofluorophotometer. In addition, the WORM ODSes enjoy the advantage of long-term stability and the rewritable ODSes can be reused many times without fatigue.