d-Penicillamine@Ag/Cu Nanocluster-Based Fluorescent Nanoneuron for Logic Screening Phosphonate-Type Organophosphate Pesticides and Steganographically Encrypting Information.

Organophosphate pesticides are used in agriculture due to their high effectiveness and low persistence in eradicating insects and pests. However, conventional detection methods encounter the limitation of undesired detection specificity. Thus, screening phosphonate-type organophosphate pesticides (OOPs) from their analogues, phosphorothioate organophosphate pesticides (SOPs), remains a challenge. Here, we reported a d-penicillamine@Ag/Cu nanocluster (DPA@Ag/Cu NCs)-based fluorescence assay to screen OOPs from 21 kinds of organophosphate pesticides, which can be used for logic sensing and information encryption. Acetylthiocholine chloride was enzymatically split by acetylcholinesterase (AChE) to produce thiocholine, which reduced the fluorescence of DPA@Ag/Cu NCs due to the transmission of electrons from DPA@Ag/Cu NCs donor to the thiol group acceptor. Impressively, OOPs acted as an AChE inhibitor and retained the high fluorescence of DPA@Ag/Cu NCs due to the stronger positive electricity of the phosphorus atom. Conversely, SOPs possessed weak toxicity to AChE, which led to low fluorescence intensity. By setting 21 kinds of organophosphate pesticides as the inputs and the fluorescence of the resulting products as the outputs, DPA@Ag/Cu NCs could serve as a fluorescent nanoneuron to construct Boolean logic tree and complex logic circuit for molecular computing. As a proof of concept, by converting the selective response patterns of DPA@Ag/Cu NCs into binary strings, molecular crypto-steganography for encoding, storing, and concealing information was successfully achieved. This study is expected to advance the progress and practical application of nanoclusters in the area of logic detection and information security while also enhancing the relationship between molecular sensors and the world of information.