Microwave-Assisted Synthesis of Silver Nanoparticles for Multimode Colorimetric Sensing of Multiplex Metal Ions and Molecular Informatization Applications

Plasmonic materials have been widely used in chemo/biosensing and biomedicine. However, little attention has been paid to the application of plasmonic materials in terms of the transition from molecular sensing to molecular informatization. Herein, we demonstrated that silver nanoparticles (AgNPs) prepared through facile and rapid microwave heating have multimode colorimetric sensing capabilities to different metal ions (Cr³⁺, Hg²⁺, and Ni²⁺), which can be further transformed into interesting and powerful molecular information technology (massively parallel molecular logic computing and molecular information protection). The prepared AgNPs can quantitatively and sensitively detect Cr³⁺ and Hg²⁺ in actual water samples. The AgNPs' multimode-guided multianalyte sensing processing was further investigated to construct a series of basic logic gates and advanced cascaded logic circuits by considering the analytes as the inputs and the colorimetric signals (like color, absorbance, wavelength shift) as the outputs. Moreover, the selective responses and molecular logic computing ability of AgNPs were also utilized to develop molecular cryptosteganography for encrypting and hiding some specific information, which proves that the molecular world and the information world are interconnected and use each other. This research not only opens the door for the transition from molecular sensing to molecular informatization but also provides an excellent opportunity for the construction of the "metaverse" of the molecular world.

Peptide-Based Sensing, Logic Computing, and Information Security on the Antimonene Platform

Peptides have higher information density than DNA and equivalent molecular recognition ability and durability. However, there are currently no reports on the comprehensive use of peptides' recognition ability and structural diversity for sensing, logic computing, information coding, and protection. Herein, we, for the first time, demonstrate peptide-based sensing, logic computing, and information security on the antimonene platform. The molecular recognition capability and structural diversity (amino acid sequence) of peptides (Pb²⁺-binding peptide DHHTQQHD as a model) adsorbed on the antimonene universal fluorescence quenching platform were comprehensively utilized to sense targets (Pb²⁺) and give a response (fluorescence turn-on) and then to encode, encrypt, and hide information. Fluorescently labeled peptides used as the recognition probe and the information carrier were quenched and hidden by the large-plane two-dimensional material antimonene and specifically bound by Pb²⁺ as the stego key, resulting in fluorescence recovery. The above interaction and signal change can be considered as a peptide-based sensing and steganographic process to further implement quantitative detection of Pb²⁺, complex logic operation, information coding, encrypting, and hiding using a peptide sequence and the binary conversion of its selectivity. This research provides a basic paradigm for the construction of a molecular sensing and informatization platform and will inspire the development of biopolymer-based molecular information technology (processing, communication, control, security).

DNA nanosensing systems for tunable detection of metal ions and molecular crypto-steganography

Various sensing platforms based on molecular or nanosystems are widely exploited through molecular diversity and specific recognition. However, it is extremely challenging to develop systems with tunable sensing ability and utilize the systems as information carriers/covers for communication and safety. Herein, DNA nanosensing systems based on cobalt oxyhydroxide (CoOOH) nanosheets were constructed for tunable detection and valence distinction of metal ions, molecular crypto-steganography, and information coding. CoOOH nanosheets absorb fluorescence-labeled single-stranded DNA with different bases and lengths, resulting in fluorescence quenching. The binding priority of bases with CoOOH nanosheets was guanine (G) > cytosine (C) > adenine (A) ≈ thymine (T) and the short chain excelled long chain. Due to the differences in the interaction among CoOOH, DNA, metal ions and variability of DNA bases, various DNA-CoOOH nanosystems have significantly different selective response patterns (that is selectivity) to metal ions and tunable linear ranges to Fe³⁺, Hg²⁺, Cr³⁺. Interestingly, by utilizing their molecular diversity, recognition, selective patterns, DNA-CoOOH sensing systems can be served as doubly cryptographic and steganographic systems to implement information encoding, encryption, and hiding and to reversely improve the selectivity of metal ions. This study provides an idea and platform for adjustable detection and valence distinction of metal ions, and gives a set of "molecular programming languages" for designing intelligent programmable sensing and molecular information communication and safety systems.

Multifunctional Carbon Nanocomposites as Nanoneurons from Multimode and Multianalyte Sensing to Molecular Logic Computing, Steganography, and Cryptography

Inspired by information exchange and logic functions of life based on molecular recognition and interaction networks, ongoing efforts are directed toward development of molecular or nanosystems for multiplexed chem/biosensing and advanced information processing. However, because of their preparation shortcomings, poor functionality, and limited paradigms, it is still a big challenge to develop advanced nanomaterials-based systems and comprehensively realize neuron-like functions from multimode sensing to molecular information processing and safety. Herein, using fish scales derived carbon nanoparticles (FSCN) as a reducing agent and stabilizer, a simple one-step synthesis method of multifunctional silver-carbon nanocomposites (AgNPs-FSCN) is developed. The prepared AgNPs-FSCN own wide antibacterial and multisignal response abilities in five channels (including color, Tyndall, absorption and fluorescence intensities, and absorption wavelength) for quantitative colorimetric and fluorescence sensing of H₂ O₂ , ascorbic acid, and dopamine. Benefiting from its multicoding stimuli-responsive ability, molecular concealment, and programmability, AgNPs-FSCN can be abstracted as nanoneurons for implementing batch and parallel molecular logic computing, steganography, and cryptography. This research will promote the preparation of advanced multifunctional nanocomposites and the development of their multipurpose applications, including the multireadout-guided multianalyte intelligent sensing and sophisticated molecular computing, communication, and security.

Graphene-Based Steganographically Aptasensing System for Information Computing, Encryption and Hiding, Fluorescence Sensing and in Vivo Imaging of Fish Pathogens

Inspired by information processing and communication of life based on complex molecular interactions, some artificial (bio)chemical systems have been developed for applications in molecular information processing or chemo/biosensing and imaging. However, little attention has been paid to simultaneously and comprehensively utilize the information computing, encoding, and molecular recognition capabilities of molecular-level systems (such as DNA-based systems) for multifunctional applications. Herein, a graphene-based steganographically aptasensing system was constructed for multifunctional application, which relies on specific molecular recognition and information encoding abilities of DNA aptamers ( Aeromonas hydrophila and Edwardsiella tarda-binding aptamers as models) and the selective adsorption and fluorescence quenching capacities of graphene oxide (GO). Although graphene-DNA systems have been widely used in biosensors and diagnostics, our proposed graphene-based aptasensing system can not only be utilized for fluorescence sensing and in vivo imaging of fish pathogens ( A. hydrophila and E. tarda), but can also function as a molecular-level logic computing system where the combination of matters (specific molecules or materials) as inputs produces the resulting product (matter level) or fluorescence (energy level) changes as two outputs. More importantly and interestingly, our graphene-based steganographically aptasensing system can also serve as a generally doubly cryptographic and steganographic system for sending different secret messages by using pathogen-binding DNA aptamers as information carriers, GO as a cover, and a pair of keys, that is, target pathogen as a public key, the encryption key used to encode or decode a message in DNA as a private key. Our study not only provides a novel nanobiosensing assay for rapid and effective sensing and in vivo imaging of fish pathogens, but also demonstrates a prototype of (bio)molecular steganography as an important and interesting extension direction of molecular information technology, which is helpful in probably promoting the development of multifunctional molecular-level devices or machines.

Matter, energy and information network of a graphene-peptide-based fluorescent sensing system for molecular logic computing, detection and imaging of cancer stem cell marker CD133 in cells and tumor tissues

A graphene-peptide-based fluorescent sensing system for molecular logic operations, sensing and imaging of CD133.