The Construction of DNA Logic Gates Restricted to Certain Live Cells Based on the Structure Programmability and Aptamer-Cell Affinity of G-Quadruplexes.

DNA computation is considered a fascinating alternative to silicon-based computers; it has evoked substantial attention and made rapid advances. Besides realizing versatile functions, implementing spatiotemporal control of logic operations, especially at the cellular level, is also of great significance to the development of DNA computation. However, developing simple and efficient methods to restrict DNA logic gates performing in live cells is still a challenge. In this work, a series of DNA logic gates was designed by taking full advantage of the diversity and programmability of the G-quadruplex (G4) structure. More importantly, by further using the high affinity and specific endocytosis of cells to aptamer G4, an INHIBIT logic gate has been realized whose operational site is precisely restricted to specific live cells. The design strategy might have great potential in the field of molecular computation and smart bio-applications.

Recent Progress in Fluorescence Signal Design for DNA-Based Logic Circuits.

DNA-based logic circuits, encoding algorithms in DNA and processing information, are pushing the frontiers of molecular computers forward, owing to DNA's advantages of stability, accessibility, manipulability, and especially inherent biological significance and potential medical application. In recent years, numerous logic functions, from arithmetic to nonarithmetic, have been realized based on DNA. However, DNA can barely provide a detectable signal by itself, so that the DNA-based circuits depend on extrinsic signal actuators. The signal strategy of carrying out a response is becoming one of the design focuses in DNA-based logic circuit construction. Although work on sequence and structure design for DNA-based circuits has been well reviewed, the strategy on signal production lacks comprehensive summary. In this review, we focused on the latest designs of fluorescent output for DNA-based logic circuits. Several basic strategies are summarized and a few designs for developing multi-output systems are provided. Finally, some current difficulties and possible opportunities were also discussed.

Intelligent Sensors of Lead Based on a Reconfigurable DNA-Supramolecule Logic Platform.

The lead (Pb) hazard is not only in connection with the concentration of Pb2+ but also closely related to the ambience which affects its mobility and the synergistic toxicity with other ions. However, most of the existent methods focus highly on detecting Pb2+ concentration accurately but can seldom reflect the pollution-related information in actual samples, thereby limiting their pragmatic applications. In this work, a DNA-supramolecule logic platform was established, which can be configurated to implement three information process functions and act as three unique intelligent sensors of Pb. The demultiplexer that can split signal flow was used to determine Pb2+ in different pH conditions; the multiplexer that can alternate signal channels was applied to detect Pb2+ or Ag+ selectively; and the decoder that can extract information was utilized to test Pb2+ and the coexisted Ni2+ simultaneously. All three intelligent sensors based on the logic prototypes present practicable sensitivities and specificities. Considering its flexibility, scalability, and reconfigurability, we believe the logic platform may provide new solutions to process sophisticated information and implement intelligent analysis in environmental monitoring, biochemical detecting, and medical diagnosis.

A resettable supramolecular platform for constructing scalable encoders.

A supramolecular platform prototype for implementing resettable encoding functions was designed, which could be configured into a series of encoders, from 4-to-2 to 7-to-3, and even 14-to-4 ECs.