Rapid and Mechanically Robust Immobilization of Proteins on Silica Studied at the Single-Molecule Level by Force Spectroscopy and Verified at the Macroscopic Level.

Typical methods for stable immobilization of proteins often involve time-consuming surface modification of silicon-based materials to enable specific binding, while the nonspecific adsorption method is faster but usually unstable. Herein, we fused a silica-binding protein, Si-tag, to target proteins so that the target proteins could attach directly to silica substrates in a single step, markedly streamlining the immobilization process. The adhesion force between the Si-tag and glass substrates was determined to be approximately 400-600 pN at the single-molecule level by atomic force microscopy, which is greater than the unfolding force of most proteins. The adhesion force of the Si-tag exhibits a slight increase when pulled from the C-terminus compared to that from the N-terminus. Furthermore, the Si-tag's adhesion force on a glass surface is marginally higher than that on a silicon nitride probe. The binding properties of the Si-tag are not obviously affected by environmental factors, including pH, salt concentration, and temperature. In addition, the macroscopic adhesion force between the Si-tag-coated hydrogel and glass substrates was ∼40 times higher than that of unmodified hydrogels. Therefore, the Si-tag, with its strong silica substrate binding ability, provides a useful tool as an excellent fusion tag for the rapid and mechanically robust immobilization of proteins on silica and for the surface coating of silica-binding materials.

The Evolutionary Game Analysis of Low Carbon Production Behaviour of Farmers, Government and Consumers in Food Safety Source Governance.

Whether the quality of agricultural products is safe or not is related to issues of food safety and low carbon production in agriculture. Based on evolutionary game theory, this paper establishes a game model among government, farmers and consumers and analyzes the dynamic evolutionary process and evolutionary stable strategies of the major stakeholders. The results show that: (i) government subsidy coefficient, farmers' penalty coefficient for not producing, consumer trust coefficient and willingness to pay carbon labelled agricultural products premium are positively related to farmers' adoption of low-carbon production behaviour, and fraud penalty coefficient and farmers' cost of adopting low-carbon production technology are negatively related; (ii) farmers' sensitivity to government regulation policies is: fraud penalty coefficient = farmers' cost of adopting low-carbon production technology > government subsidy The sensitivity of farmers to government regulation policies is: fraud penalty coefficient = cost of low-carbon production technology > government subsidy > penalty coefficient for non-production, and the sensitivity of farmers to direct market stimulation is: consumer trust coefficient > coefficient of willingness to pay premium for carbon labelled agricultural products, and the additional benefit coefficient has no significant effect on farmers' decision-making; (iii) In the early stage, the source control of food safety mainly depends on the government's policy intervention. In the later stage, the establishment of carbon label agricultural products market incentive mechanism can achieve long-term stable and effective source control of food safety.

A Lamellibranchia-inspired epidermal electrode for electrophysiology.

The capability to accurately monitor electrophysiological signals and instantly provide feedback to users is crucial for wearable healthcare. However, commercial gel electrodes suffer from drying out and irritation on skin with time, severely affecting signal quality for practical use. Toward a gel-free electrophysiology, epidermal electrodes that can accurately detect biosignals and simultaneously achieve the multifunctional properties of on-skin electronics needs are highly desirable. In this work, inspired by Lamellibranchia, which can adhere tightly to various surfaces using their extensible, adhesive and self-healing byssal threads, we developed a gel-free epidermal electrode to acquire high-quality electrophysiological signals based on a novel polymer substrate design. This polymer (STAR) features extreme stretchability (>2300% strain), high transparency (>90% transmittance at λ = 550 nm), gentle adhesion (adhesion strengths: tens of kPa), and rapid self-healing ability (95% healing efficiency in 10 min). Combined with silver nanowires as conductors, STAR was employed as a self-healing, stretchable and adhesive epidermal electrode for electrophysiological signal recording, showing a signal-to-noise ratio (SNR) even higher than that of commercial electrodes, and being able to control an artificial limb as an intermediate for human-machine interface. We believe our Lamellibranchia inspired STAR will pave a new way to design multifunctional polymers for epidermal electronics, accelerating the development of emerging wearable healthcare.