Concatenated Logic Circuits Based on a Three‐Way DNA Junction: A Keypad‐Lock Security System with Visible Readout and an Automatic Reset Function

Abstract

Concatenated logic circuits operating as a biocomputing keypad-lock security system with an automatic reset function have been successfully constructed on the basis of toehold-mediated strand displacement and three-way-DNA-junction architecture. In comparison with previously reported keypad locks, the distinctive advantage of the proposed security system is that it can be reset and cycled spontaneously a large number of times without an external stimulus, thus making practical applications possible. By the use of a split-G-quadruplex DNAzyme as the signal reporter, the output of the keypad lock can be recognized readily by the naked eye. The "lock" is opened only when the inputs are introduced in an exact order. This requirement provides defense against illegal invasion to protect information at the molecular scale.

Message in a molecule

“…Figure 4 shows a means for complicating such efforts by entering a password as an additional layer of defence. This approach exploits the principles of molecular keypad lock technology303132333435363738394041, which largely rely on the tendency of multivalent host–guest complexes and multicomponent assemblies to be entrapped in local minima41. We selected ZnCl 2 ( 1 ), Na 3 PO 4 ( 2 ) and NaOH ( 3 ) as representative entry keys owing to the strong interaction of Zn(II) with DPA ligands5556, as well as with NaOH or Na 3 PO 4 to yield Zn(OH) 2 and zinc phosphate complexes, respectively62.…”

“…Unlike its predecessor414243, however, or any other fluorescent probe that responds to several analytes2444 or an analyte group43, m-SMS was designed to operate as a universal sensor that can discriminate among a vast number of distinct chemical species. We show that this property not only distinguishes m-SMS from other types of fluorescent molecular sensors, but also from other chemical security systems45678910111213141516171819202122272829303132333435363738394041 by enabling it to function as a molecular cipher device that can convert distinct chemical structures into unique encryption keys. In this way, the system can be used not only to hide the data (steganography), but also to encrypt and decrypt it (cryptography), as well as provide password protection when a higher level of security is needed.…”

“…Another important advantage of using molecular steganography systems, namely, their small scale, has also been demonstrated by the ability to conceal messages within individual DNA strands21. Finally, advances in the area of molecular logic gates2223242526 have resulted in alternative methods of securing information222728 by using multi-analyte fluorescent molecular sensors that can produce ID-codes29 or can authorize password entries303132333435363738394041.…”

Dual-electrochromic bipolar electrode-based universal platform for the construction of various visual advanced logic devices

“…[10][11][12] Although great research achievements have been realized in this area, there is still considerable room for progress. 13,14 One significant limitation is that most of the previously reported advanced logic gates (such as full/half adder/subtractor, 15 encoder/decoder, 7,16 and multiplexer/demultiplexer 17,18 ) were fabricated using luminescent 19,20 or traditional electrochemical platforms, 10,21 whose outputs (luminescence, voltage, current) were often recorded using additional equipment and difficult to visualize by the naked eye.…”

Bis-three-way junction nanostructure and DNA machineries for ultrasensitive and specific detection of BCR/ABL fusion gene by chemiluminescence imaging

“…Up to now, self-assembly has been applied in many directions21, such as directed material assembly22, drug delivery2324 and bioanalysis2526. In bioanalysis, different biosensors have been developed for determination of a variety of analytes, including DNAzyme wires based fluorescent biosensors27, dendritic nanostructures based fluorescent biosensor28, tetrahedral DNA nanostructures based electrochemical biosensors293031, three way junction32 and ferris wheel nanostructures33 based colorimetric biosensor and so on. These architectures provide a convenient solution to improve analytical performance by the merits of precise and automated spatial control, as well as simple and robust implementation in biosensing systems.…”