Game Theory in Molecular Nanosensing System for Rapid Detection of Hg2+ in Aqueous Solutions

Abstract

Game theory—the scientific study of interactive, rational decision making—describes the interaction of two or more players from macroscopic organisms to microscopic cellular and subcellular levels. Life based on molecules is the highest and most complex expression of molecular interactions. However, using simple molecules to expand game theory for molecular decision-making remains challenging. Herein, we demonstrate a proof-of-concept molecular game-theoretical system (molecular prisoner’s dilemma) that relies on formation of the thymine–Hg2+–thymine hairpin structure specifically induced by Hg2+ and fluorescence quenching and molecular adsorption capacities of cobalt oxyhydroxide (CoOOH) nanosheets, resulting in fluorescence intensity and distribution change of polythymine oligonucleotide 33-repeat thymines (T33). The “bait” molecule, T33, interacted with two molecular players, CoOOH and Hg2+, in different states (absence = silence and presence = betrayal), regarded as strategies. We created conflicts (sharing or self-interest) of fluorescence distribution of T33, quantifiable in a 2 × 2 payoff matrix. In addition, the molecular game-theoretical-system based on T33 and CoOOH was used for sensing Hg2+ over the range of 20 to 600 nM with the detection limit of 7.94 nM (3σ) and for determination of Hg2+ in pond water. Inspired by the proof-of-concept for molecular game theory, various molecular decision-making systems could be developed, which would help promote molecular information processing and generating novel molecular intelligent decision systems for environmental monitoring and molecular diagnosis and therapy.

Microwave-Assisted Synthesis of Chromium Oxide Nanoparticles for Fluorescence Biosensing of Mercury Ions and Molecular Logic Computing

“…When Cr 2 O 3 NPs were added to the T33 solution, their absorption spectra displayed a slight redshift (264→ 266 and 488→ 492 nm). The experimental results indicated that T33 and Cr 2 O 3 NPs interacted and formed a T33–Cr 2 O 3 NP complex. , …”

“…Ono and coworkers first discovered the thymine–Hg 2+ –thymine (T–Hg 2+ –T) coordination phenomenon, , proving that Hg 2+ replaces imino protons, binding to the N3 of thymidine and connecting two thymidine residues to form the T–Hg 2+ –T pair . The strong and stable T–Hg 2+ –T base pair can be combined with fluorescence, colorimetry, electrochemistry, and other methods to monitor the Hg 2+ in the environment, , can be combined with nanomaterials for molecular sensing, , and can also be used for the construction of molecular logic gates and research on game theory strategies . For example, with the help of molecular recognition of T–Hg 2+ –T and easy fluorescence labeling characteristics of DNA, some nanosensing systems based on reduced graphene oxide, copper@gold nanoclusters, and graphite carbon nitride (g-C 3 N 4 ) nanosheets were developed to very sensitively detect Hg 2+ and implement simple molecular logic operations .…”

“…34 The strong and stable T−Hg 2+ −T base pair can be combined with fluorescence, colorimetry, electrochemistry, and other methods to monitor the Hg 2+ in the environment, 35,36 can be combined with nanomaterials for molecular sensing, 37,38 and can also be used for the construction of molecular logic gates 39 and research on game theory strategies. 40 For example, with the help of molecular recognition of T−Hg 2+ −T and easy fluorescence labeling characteristics of DNA, some nanosensing systems based on reduced graphene oxide, 41 copper@gold nanoclusters, 42 and graphite carbon nitride (g-C 3 N 4 ) nanosheets 29 were developed to very sensitively detect Hg 2+ and implement simple molecular logic operations. 41 However, there are no reports on the fluorescence quenching properties of chromium-based nanomaterials and their application in fluorescence sensing and molecular logic.…”

Aptamer-Based Biosensors for Environmental Monitoring

“…A distinct advantage of rationally designed oligonucleotide sequences with aptamer-like properties, such as the Hg 2+ binding aptamer, is that their binding and interactions are understood well enough to combine them with computational approaches to biosensor design. In fact, sequences which exploit either the T-Hg 2+ -T or C-Ag + -C interactions have been used in DNA computing applications (Nie et al, 2018). Recently, Nie et al applied game theory (a mathematical model) to understand and predict the behavior of the different component interactors in a fluorescent sensor for Hg 2+ (Nie et al, 2018).…”

“…In fact, sequences which exploit either the T-Hg 2+ -T or C-Ag + -C interactions have been used in DNA computing applications (Nie et al, 2018). Recently, Nie et al applied game theory (a mathematical model) to understand and predict the behavior of the different component interactors in a fluorescent sensor for Hg 2+ (Nie et al, 2018). In this paradigm, the aptamer was the "bait" molecule which was able to interact with two molecular players: mercury (Hg 2+ ) and cobalt oxyhydroxide nanosheets (CoOOH).…”