Peptide-based sensing of Pb2+, molecular logic computing, information encoding, cryptography, and steganography

Peptides are a class of powerful molecules and building blocks similar to DNA. However, peptides with composition diversity and molecular recognition ability are rarely used for multipurpose integrated applications (especially in sensing, information processing, communication, and security). Herein, peptide-based sensing of Pb 2+ , logic computing, information encoding, and security applications were comprehensively demonstrated. Our fluorescently labeled Pb 2+ -binding peptide exhibited different responses to various metal ions but was specific to Pb 2+ , which were attributed to the fluorescence static quenching and the transformation of the peptide conformation induced by Pb 2+ . This peptide probe was successfully used to quantitatively detect Pb 2+ (detection limit 3.38 nM) in actual water samples and to perform logic calculations. In addition, due to natural concealment of molecules, encoding, encryption, and hiding of 2 kinds of dimensional information (such as text and images), were displayed by using peptide sequences and its selectivity. This information encoding method based on molecules and their subsidiary properties shows great flexibility and scalability and provides a new option for information representation and protection. Inspired by this idea, more interesting and creative molecular sensing and information systems will be developed to promote connectivity, programmability, and intelligence of the molecular world.