A potential and ion switched molecular photonic logic gate

A molecular photonic logic gate is demonstrated by integrating electrical (potential) and chemical (ionic) switching functions into molecules attached at an externally addressable semiconductor substrate.     

Resettable fluorescence logic gate based on calcein/layered double hydroxide ultrathin films

A fluorescent logic gate was fabricated based on calcein/layered double hydroxide ultrathin films (UTFs) via alternate assembly technique, which exhibits high stability, reversibility, and resettability. The logic gate was manipulated by utilizing pH value, Hg(2+) and Cl(-) ion as inputs, and the fluorescence emission of the (calcein/LDH)(16) UTF as output, serving as a three-input logic gate that combines the YES and INHIBIT operation.     

A new fluorescence chemosensor based on benzothiazole derivative for Zn2+ and its logic gate behavior

A novel benzothiazole derivative J as a fluorescent chemosensor for Zn²⁺ has been designed and synthesized. The chemosensor J exhibits high selectivity and sensitivity to Zn²⁺ as fluorescence “turn-on” behavior, which the other cations do not make sense. The detection limit calculated by fluorescence titration method was 1.64 × 10^?8 M. Furthermore, the generated J-Zn²⁺ ensemble could recover the enhanced fluorescence upon the addition of EDTA generating an “on-off-on” recycle. In addition, the test strip based on J was fabricated, which could act as a convenient and efficient Zn²⁺ test kit.     

A versatile molecular beacon-like probe for multiplexed detection based on fluorescence polarization and its application for a resettable logic gate

A versatile molecular beacon (MB)-like probe was developed for multiplexed detection based on fluorescence polarization by target-induced allosteric effect and furthermore for resettable logic gate operation.     

A parallel electromagnetic molecular logic gate

A theoretical study of transport through a three-terminal molecular ring in the presence of a magnetic field is presented. The physical principles necessary to achieve logic operations based on the Aharonov-Bohm effect are discussed. We show that a proper combination of a gate potential and a realistic magnetic field can be used to obtain parallel logic operations such as AND and AND+NOT.     

A reversible fluorescence nanoswitch based on bifunctional reduced graphene oxide: use for detection of Hg2+ and molecular logic gate operation

Herein, we demonstrate the first use of a reduced graphene oxide (rGO)-organic dye nanoswitch for the label-free, sensitive and selective detection of Hg(2+) using bifunctional rGO as an effective nanoquencher and highly selective nanosorbent. Moreover, a reversible on-off INHIBIT rGO logic gate based on a cysteine-Hg(2+) system has also been designed.     

AND logic gate application based on colorimetric screening of enzyme activity

A simple and novel DNA and gold nanoparticle (AuNPs) based colorimetric method has been developed for efficient detection of Deoxyribonuclease I (DNase-I) activity. For the detection process, the sample that contains DNase-I, which will cleave double stranded DNA into small pieces. Furthermore, the small pieces DNA sequences and water-soluble conjugated polymer cause the AuNPs aggregation (the solution change the color from red to blue). Thus, DNase-I could be detected by naked eyes or UV/Vis. Molecular substrates can be viewed as computational devices that process physical or chemical ‘inputs’ to generate ‘outputs’ based on a set of logical operators. Based on the assay, we have presented a DNA/AuNP based, multi-readout AND logic operations.     

Molecular photonic logic gates

The possibility of performing logical operations at the molecular level is being actively investigated at present with the aim of developing molecular logic gates, which can be used in information technologies. In this minireview, the design algorithm of molecular logic gates is considered and the requirements on molecular systems for use as logic gates are specified. Examples of molecular logic gates performing different logical operations are given. Attention is focused on all-photonic molecular logic gates, in which light is used as an input signal for transferring the system from one state to another and for reading the output signal by absorption or luminescence. In addition, optoelectronic devices with light as the input signal and electric current as the output signal are briefly discussed.     

A thiol-reactive fluorescence probe based on donor-excited photoinduced electron transfer: key role of ortho substitution

We designed and synthesized a novel thiol-reactive fluorescence probe based on the BODIPY fluorophore. The fluorescence of this probe is strongly quenched by donor-excited photoinduced electron transfer (d-PeT) from BODIPY to maleimide, but after reaction with thiol, the fluorescence of BODIPY is restored, affording a 350-fold intensity increase.     

A reversible fluorescent DNA logic gate based on graphene oxide and its application for iodide sensing

A simple and reliable fluorescent DNA logic gate is developed by utilizing graphene oxide as a signal transducer and mercury ions and iodide as mechanical activators.     

Optic and proton dual-control of the fluorescence of Rhodamine based on photochromic diarylethene: mimicking the performance of an integrated logic gate

A proton and optic dual-responsive fluorescence switch dyad which contains Rhodamine and photochromic diarylethene has been designed and an integrated logic circuit at the molecular level has been proposed.     

A fluorescent molecular logic gate with multiply-configurable dual outputs

A simple molecule, L, diethylenetriamine bearing anthracene fragments at both ends, behaves as a fluorescent molecular logic gate with "multiply-configurable dual outputs", capable of demonstrating five different logic functions operated by proton (H+) and transition metal cations (Mn+) as inputs.     

Lineal DNA logic gate for microRNA diagnostics with strand displacement and fluorescence resonance energy transfer

Designing molecular logic gates to operate programmably for molecular diagnostics in molecular computing still remains challenging. Here, we designed a novel linear DNA logic gates for microRNA analysis based on strand displacement and fluorescence resonance energy transfer (FRET). Two labeled strands closed each other produce to FRET through hybridization with a complementary strand to form a basic work unit of logic gate. Two indicators of heart failure (microRNA-195 and microRNA-21) were selected as the logic inputs and the fluorescence mode was used as the logic output. We have demonstrated that the molecular logic gate mechanism worked well with the construction of YES and AND gates.     

An yttrium ion-selective fluorescence sensor based on metal ion-controlled photoinduced electron transfer in zinc porphyrin-quinone dyad

A highly Y3+-selective fluorescence sensor has been developed using zinc porphyrin-CONH-quinone dyad (ZnP-CONH-Q). The selective binding of the Q moiety of ZnP-CONH-Q with Y3+ retards electron transfer from the singlet excited state (1ZnP*) to Q, leading to a remarkable enhancement of the fluorescence intensity.     

A switchable macrocycle-clip complex that functions as a NOR logic gate

We have synthesized a new molecular switch-based on a macrocycle-clip complex-whose switching behavior not only can be controlled through the use of either K+-[2,2,2]cryptand or NH4+-Et3N systems but also provides color changes that are visible to the naked eye; consequently, this system operates as a two-input NOR functioning molecular logic gate.     

A triethylenetetramine bearing anthracene and benzophenone as a fluorescent molecular logic gate with either-or switchable dual logic functions

Fluorescence behaviors of a triethylenetetramine bearing anthracene (AN) and benzophenone (BP) fragments at the respective ends, L1, have been studied in water, where effects of pH (H+) and metal cations on the emission properties have been studied in detail. L1 behaves as a fluorescent molecular logic gate driven by H+ (Input1) and metal cations (Input2) as input chemicals. The most notable feature of L1 is that this molecule expresses the "either-or" switchable dual logic functions. Operation of L1 with Cu2+ as Input2 expresses the INHIBIT logic function, where a strong AN fluorescence appears only at pH 4 (with H+) without Cu2+ [Input1(1)-Input2(0)]. In contrast, operations of L1 with all other metal cations as Input2 express the TRANSFER logic function, where the presence of H+ allows strong AN fluorescence regardless of whether the metal cation exists or not [Input1(1)-Input2(0); Input1(1)-Input2(1)]. These emission switching behaviors of L1 are driven by the difference in the coordination stability between L1 and metal cations and the photoinduced intramolecular electron and energy transfer processes: (i) a pH-induced electron transfer from unprotonated nitrogen atoms of the polyamine chain to the photoexcited AN [ELT(N-->AN*)]; (ii) a pH- and metal coordination-induced electron transfer from the photoexcited AN to the ground-state BP [ELT(AN*-->BP)]; and (iii) a Cu2+ coordination-induced energy transfer from the photoexcited AN to Cu2+ [ENT(AN*-->Cu2+)].     

A multianalyte chemosensor on a single molecule: promising structure for an integrated logic gate

A novel fluorescent probe that possess both BODIPY and Rhodamine moieties has been designed for the selective detection of Hg(2+) and Ba(2+) ions on the controlling by a logic gate. The characteristic fluorescence of the Ba(2+)-selective OFF-ON and the Hg(2+)-selective fluorescence bathochromic shift can be observed, and the concept has been used to construct a combinational logic circuit at the molecular level. These results will be useful for further molecular design to mimic the function of the complex logic gates on controlling.