A time-locked cellulosic self-erasing material with stepwise decryption for special information transmission

Self-erasing materials with stepwise decryption are ideal for the security of information transmission. Here, a time-locked self-erasing material (TLSEM) with stepwise decryption is constructed by means of cellulose nanocrystal (CNC) bridge bond phosphor donor and gold nanoclusters (GNCs) acceptor. CNC integrated donor and acceptor, inhibited self-aggregation, enhanced the fluorescence intensity, and stability of GNCs and improved the energy transfer efficiency (49.65 %). The color pattern of TLSEM presented on the time scale was regulated by the donor and acceptor ratios based on the change in the energy transfer degree. Therefore, a TLSEM with different donor and acceptor ratios were implemented for the information encryption array, which presented the “time lock” information at 2 min and completely disappeared after 15 min through pH and cysteine encoding, and changed significantly from intricate orange–red–green to correct green with time. This time-dependent self-erasing material with stepwise decryption is excellent for special information transmission security.