A ternary addition system and calculation method based on DNA strand displacement

Abstract

The application belongs to the technical field of biological computing, and discloses a ternary addition system and a computing method based on DNA strand displacement, which comprises an input unit, a computing unit and an output unit. The input unit adds the input information to the corresponding computing module. The computing unit comprises nine modules, each of which is provided with a competitive blocking circuit and a carry computing gate, and dynamically selects a result bit 1 or 2 and generates a carry signal. The output unit outputs the digital information of 0-2 according to the fluorescent signal of the result bit, extracts the next bit carry information generated by the carry computation, amplifies the signal and then adds it to the next bit computation. The application breaks through the limitation of the number of DNA computing bits through the cooperation of the ternary gate control architecture and the fuel chain amplification, can accurately calculate the ternary addition, can expand the number of bits calculated, can realize 10-bit addition operation, and can be integrated with the expansion of the multiplication logic, thereby providing a universal framework for the molecular arithmetic unit.

Description

TECHNICAL FIELD

[0001] The present application relates to DNA molecular computing technology, and in particular to a ternary addition system and a computing method based on DNA strand displacement. BACKGROUND

[0002] DNA strand displacement reaction refers to the process of replacing one single strand in a DNA molecule with another single strand through the principle of base complementary pairing. In the field of computing science and molecular information processing, the addition system is a basic operation unit and the core of the arithmetic logic unit (ALU), which provides bottom support for high-order operations (multiplication, encryption algorithm). At present, DNA adders mainly focus on binary addition. Although people have expanded the number of bits by using the minimum number of DNA strands and developing a carry transmission mechanism, the need for multiple transmissions of carry information when calculating large numbers, the loss of carry information during transmission, the resulting signal attenuation, the error results when calculating large numbers, and the limited expression ability of the binary system significantly limit the computing scale.

[0003] For example, CN111428877A discloses a logic circuit and device based on DNA strand displacement, which adopts a binary DNA logic circuit based on threshold triggered gain adjustment, but its single digit information capacity is small and its dependence on carry is high. CN111598242A discloses a logic circuit and device based on DNA molecular chain, which adopts a multi-input gate to simplify the circuit structure to improve the building efficiency of the logic circuit based on DNA molecular chain, but it cannot solve the problem of signal attenuation in long chain calculation and cannot significantly improve the calculation accuracy.

[0004] Therefore, the traditional DNA adder is limited by the binary logic and carry attenuation problem. Although some technologies optimize the logic gate structure, they cannot break through the binary framework and multi-bit number bottleneck, resulting in the widespread dependence of the addition system on binary, high dependence on carry, inability to solve long chain calculation signal attenuation, low calculation accuracy, inability to implement 10-bit ternary addition operation, limited computing scale, and inability to flexibly convert to subtraction and multiplication operation, which greatly restricts the application range of DNA operation method and system. SUMMARY

[0005] To solve the above technical problems, the present application proposes a ternary addition system and a computing method based on DNA strand displacement, which introduces a novel competitive blocking circuit to reduce the dependence on frequent carry transmission by expanding the base of the addition system. The system adopts a dual cooperative optimization strategy to realize 10-bit ternary addition operation and to make the computing scale exceed that of the prior art, thereby achieving the effects of simultaneously improving the system efficiency, accuracy, flexibility and application range.

[0006] To achieve the above object, the present application provides the technical scheme as follows:

[0007] A ternary addition system based on DNA strand displacement, characterized in that it comprises:

[0008] An input unit: used for acquiring DNA single-strand information corresponding to two inputs of addend and addend, and adding the input information to the corresponding calculation module; loading DNA single-strand input Ai, input Bj of addend and addend, i, j = 0, 1, 2;

[0009] A calculation unit: containing 00, 01, 02, 10, 11, 12, 20, 21, and 22, a total of 9 modules, each module is provided with a competitive blocking circuit GATE1 ij / GATE2 and a carry calculation gate GATE- ij / GATE1- ij , dynamically selecting result bit 1 or 2 and generating a carry signal; the competitive blocking circuit judges whether there is carry information of the previous bit, and after the calculation is completed, the calculation result is obtained by PCR fluorescence quantitative measurement, and the carry information calculation generates the information of the next bit;

[0010] In the competitive blocking circuit, the blocking rate k 2 satisfies:

[0011] k 2=(1.8∼2.3)× k 1, and k 2>10 4 M -1 s -1 .

[0012] An output unit: including an output module and an extraction module, wherein the output module outputs digital information of 0-2 according to the fluorescence signal output by the result bit, and the extraction module is used for extracting the next bit carry information generated by the carry calculation and amplifying the signal and then adding it to the next bit calculation.

[0013] A ternary addition calculation method based on DNA strand displacement, based on the aforementioned ternary addition system, comprising the following steps:

[0014] S1: selecting a calculation module according to input Ai / Bj, and generating a result bit through a competitive blocking circuit;

[0015] S2: extracting and amplifying the carry signal, and progressing to the next bit calculation until the addition of 10 bits or less is completed.

[0016] Compared with the prior art, the ternary addition system and calculation method based on DNA strand displacement provided by the application have at least the following beneficial effects:

[0017] 1. The ternary addition operation system adopted by the application first introduces a novel competitive blocking circuit, which reduces the dependence on frequent carry transmission by expanding the base of the addition system; the system adopts a double collaborative optimization strategy, which can realize 10-bit ternary addition operation and make the scale of calculation exceed that of the prior art, thereby realizing the effects of simultaneously improving the efficiency, accuracy, flexibility and application range of the system. Compared with the traditional DNA binary adder (CN111599082A) which adopts threshold trigger gain control, only supports 4-bit (success rate 87%) calculation and has a signal loss rate of 30%, the application can realize a maximum calculation bit number of 10 bits (success rate > 99%) and a signal attenuation rate of 2.1% / bit (after magnetic bead extraction), and the total time consumption of carry transmission is significantly reduced (fuel chain amplification).

[0018] 2. The competitive blocking circuit provided by the application can accurately identify and manage the carry information of previous calculation; the core of the circuit lies in the ingenious use of the difference in reaction rate constant; experiments show that the competitive blocking circuit can reliably identify whether carry occurs in previous calculation and quickly respond to the corresponding reaction path.

[0019] 3. The circuit adopted by the application comprises an input unit for obtaining the DNA single-strand information corresponding to the inputs of the addend and the addend and adding the input information to the corresponding calculation unit; the calculation unit is divided into 9 modules, each module is provided with result bit calculation and carry information calculation, the result bit calculation uses the competitive blocking circuit to distinguish whether there is carry information of the previous bit, the calculation result is obtained by putting into PCR fluorescence quantitative measurement after the calculation is completed, and the carry information generates the next bit information; the output and extraction unit comprises an output module and an extraction module; the output module: the digital information of 0-2 is output according to the fluorescence signal output by the result bit; the extraction module: the next bit carry information generated by the carry module is extracted and amplified and then added to the next bit calculation. By improving the calculation capacity of a single bit and expanding the calculated bit, larger bit operation can be realized, the performance of a complex system can be optimized, the efficiency and accuracy can be increased when calculating large numbers, and ternary addition calculation of 10 bits and less can be successfully realized.

[0020] 4. The novel ternary encoding logic and magnetic bead-fuel chain collaborative amplification adopted by the application are irreplaceable. The novel ternary encoding logic directly represents 0 / 1 / 2 by using tri-state fluorescence (ROX / FAM / VIC), thereby avoiding multi-channel cross interference (reducing the complexity by 66% compared with the traditional 6-color encoding); the magnetic bead-fuel chain collaborative amplification realizes in-situ enrichment (concentration is increased by 103 The fuel chain cycle times are greater than 100 times (see Table 4) ; the ternary molecular logic (ternary DNA AND gate) is used to perform multi-bit processing with a carry mechanism, which greatly improves the scale of calculation.

[0021] 5、The application based on the ternary architecture and the novel gate design fills the technical gap of DNA computing in the field of efficient multi-bit processing, and has a significant breakthrough and commercialization potential compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The module composition and the calculation flowchart of the ternary addition calculation method and system based on the DNA strand displacement reaction of the embodiment of the application are shown in the figure.

[0023] Figure 2 The module composition structure diagram of the calculation unit in the ternary addition calculation system based on the DNA strand displacement reaction of the embodiment of the application is shown in the figure.

[0024] Figure 3 The schematic diagram of the modular fluorescence attachment type table of the ternary addition calculation system based on the DNA strand displacement reaction of the embodiment of the application is shown in the figure.

[0025] Figure 4 The reaction process diagram of the competitive blocking circuit based on the DNA strand displacement reaction of the embodiment of the application is shown in the figure.

[0026] Figure 5 The reaction process diagram of the carry information calculation in the calculation unit of the ternary addition calculation system based on the DNA strand displacement reaction of the embodiment of the application is shown in the figure.

[0027] Figure 6 The signal amplification reaction process diagram of the extraction module in the ternary addition calculation system based on the DNA strand displacement reaction of the embodiment of the application is shown in the figure.

[0028] Figure 7 The calculation result diagram of the ternary addition system based on the DNA strand displacement reaction of the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0029] Referring to the accompanying Figures 1 to 7 The ternary addition calculation method and system based on the DNA strand displacement reaction proposed by the application will be described and verified in detail through multiple embodiments.

[0030] Basic embodiment

[0031] Referring to the accompanying Figure 1 The ternary addition system based on the DNA strand displacement provided by the embodiment includes:

[0032] Input unit 100: for obtaining the two input DNA single strand information corresponding to the addend and the addend, and adding the input information to the corresponding calculation module; load the DNA single strand input Ai, input Bj of the addend and the addend, i, j = 0, 1, 2;

[0033] The two input DNA single strand information includes: when the addend input is 0, 1, 2, the three single strands input Ai (i = 0, 1, 2) on the opposite side, when the addend input is 0, 1, 2, the three single strands input Bj (j = 0, 1, 2) on the opposite side.

[0034] The calculation unit 110 includes 00, 01, 02, 10, 11, 12, 20, 21, 22, a total of 9 modules, and each module is provided with a competitive blocking circuit GATE1 ij / GATE2 and carry calculation gate GATE- ij / GATE1- ij , dynamically select result bit 1 or 2, and generate a carry signal; the competitive blocking circuit judges whether there is a carry information of the previous bit, and after the calculation is completed, the calculation result is put into PCR fluorescence quantitative measurement to obtain the calculation result, and the carry information calculation generates the information of the next bit;

[0035] The competitive blocking circuit has a blocking rate k 2 Satisfies:

[0036] k 2=(1.8∼2.3)× k 1, and k 2>10 4 M -1 s -1 .

[0037] The competitive blocking circuit, when there is no blocking chain, carries out the first layer reaction to generate result 1;

[0038] When there is a blocking chain, the carry information chain will block the first layer reaction and trigger the second layer reaction to generate result 2;

[0039] Wherein, the first layer and the second layer reaction include three chain gate GATE1 ij And double chain gate GATE2, the three chain gate GATE1 ij For reacting with two input chains to generate result 1, the double chain gate GATE2 is used to react with the carry information chain to generate result 2 when the carry information chain blocks the three chain gate GATE1 ij ;

[0040] The carry calculation gate includes:

[0041] GATE -ij (ij=12,21,22): three-chain gate structure, responding to high-bit input to trigger carry;

[0042] GATE1 -ij (ij=02,11,20): four-chain gate structure, cooperatively processing cross-carry logic.

[0043] In the carry information calculation, two double-chain carry information conversion gates GATE-Convertb1 and GATE-Convertb2 are further included, which are used to convert pseudo-carry information generated by the reaction into carry information; ij (ij=12,21,22): three-chain gate structure, responding to high-bit input to trigger carry;

[0044] The output unit 120 includes an output module and an extraction module, wherein the output module corresponds the fluorescent signal output by the result bit to the digital information of 0-2, and the extraction module is used to extract the next-bit carry information generated by the carry calculation and join it into the next-bit calculation after amplifying the signal.

[0045] The output unit further includes a fluorescent signal conversion module ROX / FAM / VIC and a magnetic bead extraction-fuel chain amplification module.

[0046] In the magnetic bead extraction module:

[0047] The particle size of the streptavidin magnetic bead is 50-100 nm.

[0048] The fuel chain is a classic double-stranded DNA (dsDNA) for signal amplification reaction.

[0049] In the fluorescent signal conversion module:

[0050] The ROX fluorescent label corresponds to the ternary value 0.

[0051] FAM and VIC correspond to 1 and 2 respectively, and the interval between the three-channel detection wavelengths is ≥50 nm.

[0052] The fuel chain contains a phosphorothioate modification, the nucleotide replacement modification rate is ≤15%, and the modification site per chain is ≤3 (including 3 locked nucleic acid (LNA) sites).

[0053] The biotin label of the extraction module is at the 5' end of GATE-Extract, and after magnetic bead separation, ≥10 3 times of Bin signal is generated by fuel chain circulation.

[0054] A ternary addition calculation method based on DNA strand displacement, based on the system, comprising the following steps:

[0055] S1: select the calculation module according to input Ai / Bj, generate the result bit through the competitive blocking circuit;

[0056] S2: extract the carry signal and amplify it, and progress to the next bit calculation until the 10-bit addition is completed.

[0057] The ternary addition system and calculation method based on DNA strand displacement provided by the embodiment, through the cooperation of the input unit, the calculation unit (containing 00-22 module), and the output unit (fluorescence conversion and carry extraction module), uses the competitive blocking circuit to dynamically select the result bit, and amplifies the carry signal through the fuel chain, breaks through the limitations of the prior art, and can realize the effects of 10-bit maximum calculation (success rate > 99%), signal attenuation rate 2.1% / bit (after magnetic bead extraction), reduced carry transmission time, fuel chain amplification, and the like.

[0058] The embodiment of the application creates a ternary architecture: breaking through the binary limitation of traditional DNA calculation, the single digit information capacity is improved by 50%.

[0059] Modular division: the carry logic is divided into 9 independent modules to avoid signal crosstalk and support high parallel calculation (example 1 verifies 10-bit addition).

[0060] The embodiment solves the problem of bit limitation caused by signal attenuation in the traditional scheme (the prior art only supports 4 bits), and the embodiment can support 10 bits.

[0061] Precise kinetics control is adopted to limit the blocking rate range (see example 3 gradient experiment verification) to ensure the stability of the result bit selection (error rate < 5%).

[0062] Example 1

[0063] Based on the basic embodiment, the embodiment provides a ternary addition system based on DNA strand displacement, which specifically comprises:

[0064] The input unit 100 is used to obtain the DNA single-strand information corresponding to the two inputs of the addend and the addend, and add the input information to the corresponding calculation unit;

[0065] The calculation unit 110 is divided into 9 calculation modules, each module is provided with result bit calculation and carry information calculation, the result bit calculation uses the competitive blocking circuit to participate in the calculation, the circuit can distinguish whether there is carry information of the previous bit, and after the calculation is completed, the calculation result is obtained by PCR fluorescence quantitative measurement, and the carry information generates the information of the next bit;

[0066] An output unit 120, which comprises an output module and an extraction module, the output module corresponds the digital information of 0-2 to the fluorescent signal outputted by the result bit, and the extraction module extracts the next bit carry information generated by the carry calculation and adds it to the next bit calculation unit after amplifying the signal. In the embodiment of the application, the input signal single strand refers to the DNA molecule chain, and the addend and the addend are respectively inputted as DNA single strands input A i , input B j (i=0, 1, 2; j=0, 1, 2) indicates that the output signal uses the fluorescent signal as the output (ROX corresponds to the result bit 0, FAM corresponds to the result bit 1, and VIC corresponds to the result bit 2)

[0067] Referring to Figure 2 The ternary truth table and the calculation unit are divided into nine calculation modules 00, 01, 02, 10, 11, 12, 20, 21, and 22. The DNA molecules in each module adopt different sequences according to the difference of the module and the difference of the input single strand, but the molecular structure is the same, and different fluorescent adhesions are adopted according to the result that should be outputted Figure 3 . Assuming that the 01 module, FAM is used to adhere to the triple-stranded gate GATE1 01 , and VIC is used to adhere to the double-stranded gate GATE2.

[0068] Referring to Figure 4 The calculation unit of the addition system outputs the result bit, and a competitive blocking circuit (CB) is used, which is composed of two logic gates, referred to as GATE1 ij and GATE2, representing two reaction levels. The circuit has two input signals, represented as input A i and input B j , and has a blocking signal B in . The signal B in may be in a logic state of existence or non-existence, indicating whether it participates in the reaction. Here, i, j ∈ {0, 1, 2} indicates the ternary number involved in the addition operation, and B in represents the carry information generated by the previous bit in the addition operation. When B in is in a non-existent state, the circuit receives input A i and input B j to activate the first-level reaction: , generating the result SUM1 Figure 4 (the left reaction in the figure). On the contrary, when B in exists, it reacts with GATE1 ij , effectively consuming GATE1 ij , thereby inhibiting GATE1 ijwith input inputA i and inputB j : the first order reaction: . In addition, the presence of B in can activate the second order reaction: , resulting in a different output signal in response to GATE2, denoted as SUM 2 ( Figure 4 , the right side reaction in (SUM 2 ). This indicates that in the presence of B in , it will preferentially and quickly bind to GATE1 ij , thus effectively inhibiting the first order reaction. After that, B in continues to react with GATE2. Conversely, when B in is not present, the CB circuit will continue the first order reaction.

[0069] Figure 5 The carry information calculation of the addition system described above, type a involves the generation of carry through a three-input AND gate, including cases 6, 10 and 14 in the truth table, in which the carry is generated only when B in is present. This indicates that the generation of carry information depends on input inputA i and inputB j and B in . Therefore, we use a three-input AND gate to achieve this function (GATE1- ij , where ij ∈{02, 11, 20}). The structure of GATE1- ij includes four single strands, which form a stable structure through base pairing in toehold regions t a and t b and longer domains a i , b j and c. At the same time, it exposes toehold t a *and longer domain r. When all three inputs, input inputA i and inputB j and B in are present, this gate generates a c r carrying information chain. The specific reaction mechanism is described in (a) of Figure 5 .

[0070] Type b is the generation of carry through a two-input AND gate and a conversion gate, including cases 11, 12, 15, 16, 17 and 18 in the truth table, in which the carry will be generated for the next bit regardless of the carry input B in . This indicates that the carry information only depends on input inputA i and inputB jWe use a two-input AND gate (GATE). -ij (where ij ∈ {12, 21, 22}) to implement these cases. GATE- ij The structure consists of three single chains, connected by toehold t b and long domain a i and b j Base pairing is stable. This exposes toehold t. a * and the longer field r. When inputA i and inputB j When both conditions are met, the gate produces an output. The specific reaction mechanism is as follows: Figure 5 As shown in (b). When inputA i and inputB j When both exist, b j The single chain containing r is replaced. Further, we use GATE-Convertb... j (j = 1, 2, GATE-Convertb) j The structure consists of two single chains, one of which contains the carry information to be passed to the next bit (to transfer b). j r is converted into carry information cr single chain.

[0071] Furthermore, we use the carry information extractor GATE-Extract (see reference) in the extraction module. Figure 5 In the middle (c), the structure forms a hairpin shape through self-complementary base pairing between the structural domains c and c′, where the foothold t r Embedded within a hairpin, with biotin attached to its 5' end. When carry information is present in the test tube, the hairpin's structural domain r' undergoes a chain substitution reaction with the structural domain r of the information chain cr. This reaction opens the hairpin structure, exposing the toehold t. r The extended long domain c is called CC. The extractor, combined with carry information, places streptavidin magnetic beads to extract the CC. The streptavidin magnetic beads can bind tightly to biotin and can be attracted by a magnetic frame.

[0072] The specific working steps of the extraction module are as follows: The completed reaction system is placed on a magnetic rack. The GATE-Extract, bound to streptavidin magnetic beads, will be magnetically adsorbed to the bottom of the test tube. After discarding the supernatant, refer to... Figure 6 A dual-chain signal amplification gate (GATE-amplifier) ​​and a fuel chain are added for signal amplification. The carry information (Bin) is extracted from the gate via a chain substitution reaction between the CC and GATE-amplifier, simultaneously exposing the toehold t within the gate. xThe generated products then react with toehold t in the fuel chain. x By combining, the opened GATE-Extract is re-displaced through a chain substitution reaction, allowing it to continue reacting with the GATE-amplifier to generate more B. in This amplifies the signal, and after another magnetic separation, the supernatant is added to the next calculation module.

[0073] This embodiment provides high stability for long-chain computation, achieved through modular carry separation (… Figure 6 The signal strength retention rate remains at 78.5% even at the 10th bit (compared to 31% at the 6th bit in traditional schemes); energy consumption is significantly reduced, with a computational energy consumption of 0.3nJ per bit, which is only 0.02% of that of the optical quantum computing chip (IBM Q System One); and it has technical advantages, as shown in the graph comparing the number of computation bits and the signal attenuation rate (data:image / png;base64 and simulated line graph). In this embodiment, the attenuation rate is only 21% when performing 10-bit computation, while the attenuation rate of the prior art exceeds 30% when performing 4-bit computation.

[0074] Example 2

[0075] Based on the basic embodiment and embodiment 1, this embodiment further verifies the performance of 10-bit ternary addition.

[0076] To evaluate the feasibility of a ternary addition system based on DNA strand substitution, a 10-bit ternary addition calculation (1012212101+2211220122) was implemented. First, input A1 and input B2 were added to designated test tubes in the 12-module. Then, the result bit in the test tube was calculated using a competitive blocking circuit. The fluorescence signal of the result was measured by PCR, and subsequently extracted using an extractor in the extraction module. The carry information was calculated and amplified. After a round of magnetic separation, the supernatant, along with the input for the next bit, was transferred to the next bit calculation module (input A0 and input B2). The output from the fluorescence reporter gate was then recorded. This process continued until all bits were calculated, and the result was recorded. Figure 7 The figure shows that the gray, red, and blue curves correspond to the fluorescence signals of ROX, FAM, and VIC, representing values ​​of 0, 1, and 2, respectively. The total result shown in the figure is 11001210000, thus confirming the feasibility and accuracy of the design.

[0077] Test case: 1012212101 + 2211220122 = 11001210000

[0078] Quantification results are shown Figure 5 :

[0079] Bit error rate: 7th bit FAM signal drift <5% (error correction after meeting the standard).

[0080] Example 3

[0081] This embodiment is based on the basic embodiment and examples 1-2, and this embodiment further carries out dynamic parameter adjustment optimization. The fuel chain concentration gradient experimental parameters are shown in Table 4.

[0082] Table 4

[0083]

[0084] Conclusion: 100nM reaches the optimal balance (amplification factor and stability are positively correlated).

[0085] Example 4

[0086] This embodiment is based on the basic embodiment and examples 1-3, and this embodiment further carries out mixed logic operation integration.

[0087] The ternary addition system based on DNA strand displacement, the competitive blocking circuit and the AND gate are integrated to form a ternary multiplication unit, and the input chain contains a multi-target calibration bit sequence; the system supports ternary subtraction operation by adjusting the concentration ratio of GATE1 ij in the range of 1: (0.2~5).

[0088] Ternary multiplication verification: 2x2=11 (ternary), experimental data shows:

[0089] The success rate of NAND gate cooperative operation is 91%, which is 40% higher than single addition.

[0090] Maximum support for 6-bit ternary multiplication.

[0091] From the above embodiments, it can be found that the logic circuit based on DNA strand displacement adopted by the present application can accurately calculate ternary addition through the input unit, the calculation unit and the output unit, and can also expand the number of bits calculated by adjusting the concentration ratio. The invention breaks through the limitation of DNA calculation bits through the cooperation of ternary gate control architecture and fuel chain amplification. The above embodiments verify the optimization of dynamic parameter adjustment on signal stability, and realize the expansion and integration of multiplication logic, providing a universal framework for molecular arithmetic units.

[0092] Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A ternary addition system based on DNA strand substitution, characterized in that, It includes: Input unit: Used to obtain the DNA single-strand information of the two inputs, the addend and the augend, and add the input information to the corresponding calculation module; load the DNA single strands of the addend and the augend: input Ai, input Bj, i,j=0,1,2; Computing Unit: Contains 9 computing modules (00, 01, 02, 10, 11, 12, 20, 21, 22), each containing a competitive blocking circuit (GATE1). ij / GATE2 and carry calculation gate GATE- ij / GATE1- ij The result is dynamically selected as 1 or 2, and a carry signal is generated. The competitive blocking circuit determines whether there is carry information from the previous bit. After the calculation is completed, the result is obtained by PCR fluorescence quantitative measurement. The carry information is used to generate the information for the next bit. Output unit: includes an output module and an extraction module. The output module outputs the fluorescent signal corresponding to the result bit and outputs digital information of 0-2. The extraction module is used to extract the carry information of the next bit generated by the carry calculation, amplify the signal and add it to the next bit calculation. The carry calculation gate includes: GATE- ij (ij=12,21,22): Three-chain gate structure, responding to high-order input to trigger carry; GATE1- ij (ij=02,11,20): Four-chain gate structure, coordinating the handling of cross-carry logic; The competitive blocking circuit of the computing unit performs the first-level reaction when there is no blocking chain, producing result 1; When a blocking chain exists, the carry information chain will block the first-level reaction and trigger the second-level reaction, resulting in result 2; The first and second layer reactions include a triple-gate GATE1 ij And the double-chain gate GATE2, the triple-chain gate GATE1 ij The double-chain gate GATE2 is used to generate result 1 by reacting with two input chains. It is used to block the triple-chain gate GATE1 when there is a carry information chain. ij At that time, the result 2 is generated in response to the carry information chain.

2. The ternary addition system based on DNA strand substitution according to claim 1, characterized in that, In the competitive blocking circuit, the blocking rate k 2 satisfy: k 2 = (1.8 ~ 2.3) × k 1, and k 2>10 4 M -1 s -1 .

3. The ternary addition system based on DNA strand substitution according to claim 1, characterized in that, The output unit also includes a fluorescence signal conversion module ROX / FAM / VIC and a magnetic bead extraction-fuel chain amplification module; In the magnetic bead extraction-fuel chain amplification module: The particle size of streptavidin magnetic beads is 50-100 nm; The fuel chain is a double-stranded DNA, used for signal amplification reactions; In the fluorescence signal conversion module: The ROX fluorescent marker corresponds to the ternary value 0; FAM and VIC correspond to 1 and 2 respectively, and the wavelength interval of the three channels is ≥50nm; The fuel chain contains thiophosphate modification, and each chain has ≤3 modification sites; The biotin in the extraction module is labeled at the 5' end of the GATE-Extract. After separation by magnetic beads, it is recycled through the fuel chain to generate ≥10 3 The Bin signal is twice as strong.

4. The ternary addition system based on DNA strand substitution according to claim 1, characterized in that, The carry information calculation also includes two double-chain carry information conversion gates, GATE-Convertb1 and GATE-Convertb2. These double-chain carry information conversion gates are used to convert the carry information of the triple-chain gate GATE-Convertb1 into a single carry information. ij The pseudo-carry information generated by the reaction is converted into carry information.

5. The ternary addition system based on DNA strand substitution according to claim 1, characterized in that, The two input DNA single-strand information include: when the addend input is 0, 1, 2, the three single strands inputAi (i=0, 1, 2) are respectively opposite to each other; when the addend input is 0, 1, 2, the three single strands inputBj (j=0, 1, 2) are respectively opposite to each other.

6. The ternary addition system based on DNA strand substitution according to claim 1, characterized in that, The competitive blocking circuit is integrated with the AND gate to form a ternary multiplication unit, and the input chain contains a multi-target positioning sequence.

7. The ternary addition system based on DNA strand substitution according to any one of claims 1-6, characterized in that, By adjusting GATE1 within the range of 1: (0.2~5) ij The concentration ratio supports ternary subtraction operations.

8. A ternary addition calculation method based on DNA strand substitution, characterized in that, The ternary addition system according to any one of claims 1-7 includes the following steps: S1: Select the calculation module based on input Ai / Bj, and generate the result bit through a competitive blocking circuit; S2: Extract the carry signal and amplify it, then proceed to the next bit for calculation until the addition of 10 bits or less is completed.

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