共查询到20条相似文献，搜索用时 0 毫秒
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Na Zhang Wai‐Yip Lo Anex Jose Zhengxu Cai Lianwei Li Luping Yu 《Advanced materials (Deerfield Beach, Fla.)》2017,29(28)
Single‐molecular electronics is a potential solution to nanoscale electronic devices. While simple functional single‐molecule devices such as diodes, switches, and wires are well studied, complex single‐molecular systems with multiple functional units are rarely investigated. Here, a single‐molecule AND logic gate is constructed from a proton‐switchable edge‐on gated pyridinoparacyclophane unit with a light‐switchable diarylethene unit. The AND gate can be controlled orthogonally by light and protonation and produce desired electrical output at room temperature. The AND gate shows high conductivity when treated with UV light and in the neutral state, and low conductivity when treated either with visible light or acid. A conductance difference of 7.3 is observed for the switching from the highest conducting state to second‐highest conducting state and a conductance ratio of 94 is observed between the most and least conducting states. The orthogonality of the two stimuli is further demonstrated by UV–vis, NMR, and density function theory calculations. This is a demonstration of concept of constructing a complex single‐molecule electronic device from two coupled functional units. 相似文献
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The first ever implementation of a thermal AND gate, which performs logic calculations with phonons, is presented using two identical thermal diodes composed of asymmetric graphene nanoribbons (GNRs). Employing molecular dynamics simulations, the characteristics of this AND gate are investigated and compared with those for an electrical AND gate. The thermal gate mechanism originates through thermal rectification due to asymmetric phonon boundary scattering in the two diodes, which is only effective at the nanoscale and at the temperatures much below the room temperature. Due to the high phonon velocity in graphene, the gate has a fast switching time of ≈100 ps. 相似文献
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Shengwang Zhou Xuezhong Du Fangbo Cui Xianfeng Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(5):980-988
Novel DNA‐gated mesoporous silica nanoparticle (MSN) vehicles functionalized with disulfide‐linked acridinamine intercalators are constructed for multi‐responsive controlled release. The DNA‐gated MSN vehicles release cargo encapsulated in the MSN pores under different stimuli, including disulfide reducing agents, elevated temperature, and deoxyribonuclease I (DNase I), for codelivery of drugs and DNA/genes in different forms. Furthermore, the cascade release of encapsulated and intercalative drugs is controlled by AND logic gates in combination of dual stimuli. The ingeniously designed DNA‐gated MSN vehicles integrates multiple responses and AND logic gate operations into a single smart nanodevice not only for codelivery of drugs and DNA/genes but also for cascade release of two drugs and has promising biological applications to meet diverse requirements of controlled release. 相似文献
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Constantin Pistol Vincent Mao Viresh Thusu Alvin R. Lebeck Chris Dwyer 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(7):843-850
The self‐assembly of molecularly precise nanostructures is widely expected to form the basis of future high‐speed integrated circuits, but the technologies suitable for such circuits are not well understood. In this work, DNA self‐assembly is used to create molecular logic circuits that can selectively identify specific biomolecules in solution by encoding the optical response of near‐field coupled arrangements of chromophores. The resulting circuits can detect label‐free, femtomole quantities of multiple proteins, DNA oligomers, and small fragments of RNA in solution via ensemble optical measurements. This method, which is capable of creating multiple logic‐gate–sensor pairs on a 2 × 80 × 80‐nm DNA grid, is a step toward more sophisticated nanoscale logic circuits capable of interfacing computers with biological processes. 相似文献
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Qiao Jiang Zhen‐Gang Wang Baoquan Ding 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(7):1016-1020
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Mette D. E. Jepsen Lasse L. Hildebrandt Victoria Birkedal Jørgen Kjems 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(15):1811-1817
Logic gates are devices that can perform logical operations by transforming a set of inputs into a predictable single detectable output. The hybridization properties, structure, and function of nucleic acids can be used to make DNA‐based logic gates. These devices are important modules in molecular computing and biosensing. The ideal logic gate system should provide a wide selection of logical operations, and be integrable in multiple copies into more complex structures. Here we show the successful construction of a small DNA‐based logic gate complex that produces fluorescent outputs corresponding to the operation of the six Boolean logic gates AND, NAND, OR, NOR, XOR, and XNOR. The logic gate complex is shown to work also when implemented in a three‐dimensional DNA origami box structure, where it controlled the position of the lid in a closed or open position. Implementation of multiple microRNA sensitive DNA locks on one DNA origami box structure enabled fuzzy logical operation that allows biosensing of complex molecular signals. Integrating logic gates with DNA origami systems opens a vast avenue to applications in the fields of nanomedicine for diagnostics and therapeutics. 相似文献
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Sudhanshu Garg Shalin Shah Hieu Bui Tianqi Song Reem Mokhtar John Reif 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(33)
DNA devices have been shown to be capable of evaluating Boolean logic. Several robust designs for DNA circuits have been demonstrated. Some prior DNA‐based circuits are use‐once circuits since the gate motifs of the DNA circuits get permanently destroyed as a side effect of the computation, and hence cannot respond correctly to subsequent changes in inputs. Other DNA‐based circuits use a large reservoir of buffered gates to replace the working gates of the circuit and can be used to drive a finite number of computation cycles. In many applications of DNA circuits, the inputs are inherently asynchronous, and this necessitates that the DNA circuits be asynchronous: the output must always be correct regardless of differences in the arrival time of inputs. This paper demonstrates: 1) renewable DNA circuits, which can be manually reverted to their original state by addition of DNA strands, and 2) time‐responsive DNA circuits, where if the inputs change over time, the DNA circuit can recompute the output correctly based on the new inputs, that are manually added after the system has been reset. The properties of renewable, asynchronous, and time‐responsiveness appear to be central to molecular‐scale systems; for example, self‐regulation in cellular organisms. 相似文献
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Kyung Hoon Kim Jung Kim Jong Seob Choi Sunwoong Bae Donguk Kwon Inkyu Park Do Hyun Kim Tae Seok Seo 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(46):6215-6224
Tracking and monitoring the intracellular behavior of mRNA is of paramount importance for understanding real‐time gene expression in cell biology. To detect specific mRNA sequences, molecular beacons (MBs) have been widely employed as sensing probes. Although numerous strategies for MB delivery into the target cells have been reported, many issues such as the cytotoxicity of the carriers, dependence on the random probability of MB transfer, and critical cellular damage still need to be overcome. Herein, we have developed a nanowire‐incorporated and pneumatic pressure‐driven microdevice for rapid, high‐throughput, and direct MB delivery to human breast cancer MCF‐7 cells to monitor survivin mRNA expression. The proposed microdevice is composed of three layers: a pump‐associated glass manifold layer, a monolithic polydimethylsiloxane (PDMS) membrane, and a ZnO nanowire‐patterned microchannel layer. The MB is immobilized on the ZnO nanowires by disulfide bonding, and the glass manifold and PDMS membrane serve as a microvalve, so that the cellular attachment and detachment on the MB‐coated nanowire array can be manipulated. The combination of the nanowire‐mediated MB delivery and the microvalve function enable the transfer of MB into the cells in a controllable way with high cell viability and to detect survivin mRNA expression quantitatively after docetaxel treatment. 相似文献
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Kaiyue Tan Yingying Chen Kang Ma Qing Wang Xiaoqing Liu Fuan Wang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(40)
Mitochondrial membrane potential (MMP) represents an essential parameter of cellular activities, and even a minute MMP variation could significantly affect the biological functions of living organisms. Thus, convenient and accurate MMP detection is highly desirable since conventional MMP probes are always constrained by photobleaching, inconvenience, and irreversibility. Herein, a spatial‐dependent fluorescent molecular rotor Mito‐Cy is introduced for efficiently tracking the varied MMP status through its restricted intramolecular rotation in mitochondria and nucleus compartments. Based on a systematic investigation, the specifically lit up fluorescent Mito‐Cy enables us to explore different MMP situations by determining their varied distributions. Accordingly, Mito‐Cy concentrates in mitochondria under normal MMP status. Yet Mito‐Cy starts to migrate gradually from mitochondria to the nucleus in decreasing MMP status, as represented by the increasing distribution levels of fluorescent Mito‐Cy in the nucleus. Mito‐Cy exclusively accumulates in the nucleus at ultimate vanishing MMP status. The facile operation of Mito‐Cy, together with its high photostability and sensitivity, facilitates the monitoring of the reversible and programmable MMP evolutions in living cells. The Mito‐Cy‐involved logic control over MMP, e.g., AND and OR gates, indicates that the robust and versatile Mito‐Cy holds great potential for illuminating mitochondrial viscosity‐related bioprocesses. 相似文献
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Angeliki Moutsiopoulou David Broyles Emre Dikici Sylvia Daunert Sapna K. Deo 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(35)
The ability to monitor types, concentrations, and activities of different biomolecules is essential to obtain information about the molecular processes within cells. Successful monitoring requires a sensitive and selective tool that can respond to these molecular changes. Molecular aptamer beacon (MAB) is a molecular imaging and detection tool that enables visualization of small or large molecules by combining the selectivity and sensitivity of molecular beacon and aptamer technologies. MAB design leverages structure switching and specific recognition to yield an optical on/off switch in the presence of the target. Various donor–quencher pairs such as fluorescent dyes, quantum dots, carbon‐based materials, and metallic nanoparticles have been employed in the design of MABs. In this work, the diverse biomedical applications of MAB technology are focused on. Different conjugation strategies for the energy donor–acceptor pairs are addressed, and the overall sensitivities of each detection system are discussed. The future potential of this technology in the fields of biomedical research and diagnostics is also highlighted. 相似文献
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Natalie Fardian‐Melamed Gennady Eidelshtein Dvir Rotem Alexander Kotlyar Danny Porath 《Advanced materials (Deerfield Beach, Fla.)》2019,31(35)
The quest for a suitable molecule to pave the way to molecular nanoelectronics has been met with obstacles for over a decade. Candidate molecules such as carbon nanotubes lack the appealing trait of self‐assembly, while DNA seems to lack the desirable feature of conductivity. Silver‐containing poly(dG)–poly(dC) DNA (E‐DNA) molecules have recently been reported as promising candidates for molecular electronics, owing to the selectivity of their metallization, their thin and uniform structure, their resistance to deformation, and their maximum possible high conductivity. Ultrahigh vacuum (UHV) scanning tunneling microscopy (STM) of E‐DNA presents an elaborate high‐resolution morphology characterization of these unique molecules, along with a detailed depiction of their electronic level structure. The energy levels found for E‐DNA indicate a novel truly hybrid metal–molecule structure, potentially more conductive than other DNA‐based alternatives. 相似文献