Logic Gates Research Articles

Heterocyclic-based Optical Responsive Chemosensors for the detection of Arsenite and Phosphate in semi-aqueous medium: Application in Logic gate operations, RGB tool, and DFT studies

Highly selective and sensitive organic chemosensors S2R1-S2R3 were synthesized using thienyl-substituted pyridine derivative and characterized by various spectroscopic techniques. The effect of substituents on selectivity is observed in the chemosensors S2R1 through S2R3, with the rate of reactivity toward ions following the trend as -NO2 > -CN > -OCH3 group. The chemosensor S2R1 exhibited selectivity towards arsenite and phosphate, achieving a Limit of Detection (LOD) of 0.2672 ppm and 0.5042 ppm, respectively, in 30% aq. (CH3)2SO solution. It was also observed that S2R2 was selective for PO43− ions in 100% (CH3)2SO solution with an LOD of 0.521 ppm. The spectral redshifts observed in the organo-aqueous media potentializes the sensor to be colorimetrically active. The probe S2R1 showed the lowest LOD and high binding constant with AsO2− and PO43− ions. Other characterization techniques, such as electrochemical studies, 1H-NMR titration, UV-visible titration, and DFT experiments, demonstrated the sensing mechanism of arsenite and phosphate ions with the chemosensors through an intermolecular hydrogen bonding and intermolecular charge transfer (ICT) process followed by its practical applicability for real world-sensing.

A Click-generated chalcone allied triazole sensor for Co (II) with INHIBIT logic gate construction and its antioxidant properties

A Click-generated chalcone allied triazole sensor for Co (II) with INHIBIT logic gate construction and its antioxidant properties

Device Applications Enabled by Bandgap Engineering Through Quantum Dot Tuning: A Review.

Quantum dots (QDs) are becoming essential materials for future scientific and real-world applications, owing to their interesting and distinct optical and electrical properties compared to their bulk-state counterparts. The ability to tune the bandgap of QDs based on size and composition-a key characteristic-opens up new possibilities for enhancing the performance of various optoelectronic devices. These advances could extend to cutting-edge applications such as ultrawide-band or dual-band photodetectors (PDs), optoelectronic logic gates, neuromorphic devices, and security functions. This paper revisits the recent progress in QD-embedded optoelectronic applications, focusing on bandgap tunability. The current limitations and challenges in advancing and realizing QD-based optoelectronic devices are also discussed.

Four‐State Electrochromism in Tris(4‐aminophenyl)amine‐ terephthalaldehyde‐based Covalent Organic Framework

AbstractCovalent organic frameworks (COFs) are of massive interest due to their potential application spanning diverse fields such as gas storage and separation, catalysis, drug delivery systems, sensing, and organic electronics. In view of their application‐oriented quest, the field of electrochromism marked a significant stride with the reporting of the first electrochromic COF in 2019 [J. Am. Chem. Soc. 2019, 141, 19831–19838]. Since then, new and novel COF structures with electrochromic features (denoted as ecCOFs) have been searched continuously. Yet, only a handful of ecCOFs have been constructed to date. A closer look at these reports suggests that multielectrochromism (showing at least three redox color states) in a COF assembly has only been achieved once, manifested through three‐state electrochromism [Angew. Chem. 2021, 133, 12606–1261]. Herein, we report four‐state electrochromism in tris(4‐aminophenyl)amine‐terephthalaldehyde (TAPA‐PDA)‐based COF constructed through the metal‐catalyst free Schiff base approach. The four‐state (orange, pear, green, and cyan) electrochromism demonstrated by the TAPA‐PDA ecCOF opens several futuristic avenues for ecCOF′s end use in flip‐flop logic gates, intelligent windows, decorative displays, and energy‐saving devices.

Design and Optimization of the 4-Bit Absolute Value Logic Gate Circuits

Absolute value computation of binary numbers has important applications in digital signal processing and arithmetic operations, but conventional circuit designs usually face high latency and energy consumption problems. In order to improve computational efficiency, this paper proposes an optimization method based on logic gate circuits aimed at reducing the number of physical components and simplifying the circuit structure. By using a truth table for logic simplification, a more efficient 4-bit absolute value calculation circuit is designed in this study. Experimental results show that the optimised circuit performs significantly in reducing latency and power consumption and maintains the accuracy of the operation. The results of the study provide a better implementation of digital circuit design for application scenarios that require efficient computation.

New Approach in Booth Decoder/Encoder and 5-2 Compressor for Multipliers

This paper proposes two novel approaches: a signed–unsigned modified Booth decoder/encoder that is used for the production of partial products and a 5-2 compressor for the addition stage of partial products. The improvement of a circuit can be done at the transistor level and the gate level. To improve the circuits at the gate level for the modified Booth decoder/encoder, a new table was designed and also the 5-2 compressor was obtained by changing the truth table. Speed, power consumption and area were improved in the proposed structures. In this paper, at the transistor level, the gate diffusion input (GDI) technique was used to implement logical gates and the gate-level delay of the GDI structures was also calculated. The results indicated that the proposed 5-2 compressor had a delay of 119 ps with a power consumption of 65[Formula: see text][Formula: see text]W, which shows a 23.5% improvement in power delay product (PDP) compared to the best structure in the comparison table, whereas the proposed Booth decoder/encoder had a delay of 257 ps with a power consumption of 61.74[Formula: see text][Formula: see text]W and shows a 63.7% improvement in PDP compared to previous studies. By using the proposed structures in the multiplier, a 22% improvement in PDP was observed. To simulate the obtained structures, the TSMC 0.18 and 0.09[Formula: see text][Formula: see text]m technologies and the HSPICE software were used. Cadence software was used to implement the layouts of the proposed structures.

Optoelectronic Reconfigurable Logic Gates Based on Two-Dimensional Vertical Field-Effect Transistors.

Optoelectronic reconfigurable logic gates are promising candidates to meet the multifunctional and energy-efficient requirements of integrated circuits. However, complex device architectures need more power and hinder multifunctional device applications. Here, we design vertical field-effect transistors (VFET) based on the two-dimensional (2D) graphene/MoS2/WSe2/graphene van der Waals heterojunction forming ohmic and Schottky contact. The modulation of the Schottky barrier via gate bias enables the device to switch between positive and negative photocurrents, which can effectively achieve optoelectronic reconfigurable logic gates (XNOR, NOR, NAND, AND, OR, and Inhibit) in a single device. Particularly, the transistor number is reduced by 75% for ("XNOR", "NOR", "NAND") and 83% for ("AND", "OR") gates compared to traditional logic circuits. This work provides a promising route for using a single device to realize optoelectronic reconfigurable logic gates, which can advance the development of high-speed, high-throughput, and intricate data processing in future optical computing applications.

Thermal modelling and layout optimization of GaN half-bridge IC with integrated drivers and power HEMTs

The paper presents the results of thermal modeling of a half-bridge monolithic integrated circuit (IC) with integrated drivers and enhanced mode power high electron mobility transistors, based on a GaN-on-SOI heterostructure. It had been established that the main heat sources in the IC were the half-bridge GaN HEMTs. The heat from the half-bridge GaN HEMTs propagates in the chip and leads to heating of the logic block and gate drivers. Heating of half-bridge GaN HEMTs leads to increased channel resistance and IC output current drop. Heating of the gate drivers reduces driving current, as a result, increases the switching time of the half-bridge GaN HEMTs. Heating of the logic block increases the rise and fall times of the generated control signals, which worsens the dynamic characteristics of the IC. A comparative analysis of heat propagation for IC dies based on GaN-on-SOI and GaN-on-Si heterostructures showed that GaN-on-SOI structure has a 40% greater junction-to-backside thermal resistivity compared to GaN-on-Si structure. In this case, the specific thermal resistance in the direction of heat propagation from the hotspot of the transistor to the backside of the die for the GaN-on-SOI structure is almost two orders of magnitude greater than in the direction of its propagation to the frontside of the chip. The results obtained were used for IC layout optimization. The rearrangement of GaN-on-SOI IC functional blocks, as well as to introduction of additional heat-spreading elements on the frontside of chip were carried out during the optimization.

OPTIMIZATION PROBLEM FOR NUMBER OF LOGIC GATES NEEDED TO IMPLEMENT MULTIPLE BOOLEAN FUNCTIONS USING DECODER

Abstract. Background. Computer circuits enable almost every piece of electronics to function. An opportunity for their optimization was found in one of the ways to implement a circuit, which involves a decoder. Decoders are basic circuit components whose behavior makes it easy to implement multiple Boolean functions. Functions are just rules by which informational signals are being processed in the circuit. To implement a function Logic gatEs (LEs) are used. LEs group multiple input signals and process them using binary logic operators like AND or NOR. Purpose. Develop a computer program that, based on provided functions, will find a solution associated with approximately minimal number of logic gates. Relevance. Prevalence of circuits increases the value of small optimizations, since any improvement gets multiplied by millions of circuits produced. Optimization at the logic level is being explored, which will retain value regardless of the physical properties of the circuit. Additionally, the theory of optimizing LE usage for circuits built on decoders is examined, which will alleviate future research. Methods. Development of the theory arose from an understanding that input signals can be grouped using LEs consciously. This way, LE outputs can be used in more than one function, which results in reduction of total number of LEs. It becomes evident that the problem can be restated in terms of sets. Similarity to known NP-hard problems emerges, which prompts usage of existing solution approaches. Among them, the greedy algorithm is chosen for its simplicity in program implementation. The connection between the problem and digital circuitry is weakened by the introduction of special evaluation functions that work with sets. So, the problem is reduced to several mathematical rules, which then are used as the appropriate parts of the greedy algorithm. Development of knowledge necessary to create the target program is thus concluded. Results. The target program is successfully implemented and can be seen in full at https://github.com/Gleb-05/MakeFuncForDC. A test is conducted on 1000 sets of four pseudorandom eight-term functions. It is estimated that the implementations proposed by the program require on average 0.75 of the initial number of LEs. The average running time is estimated at 2 milliseconds. In contrast, brute-force search for the same problem is theorized to run for years. Conclusions. A working program that finds an almost optimal solution is successfully created and tested. Its performance makes it potentially useful in the industrial scale of circuit manufacturing. Since the program essentially offers workload management, its possible applications go beyond the domain of digital electronics. Additionally, the theory of optimizing the use of LEs is presented for the first time. It can be used as the basis for future research on the implementation of multiple Boolean functions using decoder.

Anisotropic nonlinear optical responses of Ta2NiS5 flake towards ultrafast logic gates and secure all-optical information transmission

Abstract Optical logic gates based on nonlinear optical property of material with ultrafast response speed and excellent computational processing power can break the performance bottleneck of electronic transistors. As one of the layered 2D materials, Ta2NiS5 exhibits high anisotropic mobility, exotic electrical response, and intriguing optical properties. Due to the low-symmetrical crystal structures, it possesses in-plane anisotropic physical properties. The optical absorption information of Ta2NiS5 is investigated by anisotropic linear absorption spectra, femtosecond laser intensity scanning (I-scan), and non-degenerate pump-probe technology. The I-scan results show a distinct maximum of ∼4.9 % saturable absorption (SA) and ∼4 % reverse saturable absorption (RSA) at different polarization directions of the incident laser. And, these unique nonlinear optical (NLO) properties originate from the anisotropic optical transition probability. Furthermore, the novel Ta2NiS5-based all-optical logic gates are proposed by manipulating the NLO absorption processes. And, the all-optical OR and NOR logic gates possess an ultrafast response speed approaching 1.7 THz. Meanwhile, an all-optical information transmission method with higher security and accuracy is achieved, which has promising potential to avoid the disclosure of information. This work provides a new path for designing versatile and novel optical applications based on Ta2NiS5 materials.

CRISPR-based molecule-regulatory expression platform for specific immunotherapy of cancer.

Cancer is still a major challenge of human health. The abnormality of intracellular cancer-related signal pathways is an important mechanism for the occurrence of cancer. We used a molecular-senor to act on the endogenous signal molecules within the cell to redirect the abnormal signal flows in the cell to treat cancer. Based on CRISPR-dCas12f procedures, we combined aptamers and ribozymes to construct riboswitches, which served as molecular switches to reprogram sgRNAs, so that CRISPR-dCas12f redirected the intracellular anti-cancer signal flows after sensing specific input signal molecules. In addition, the activated molecular sensors and the inhibitory molecular sensors were constructed by combining transcription factors (VP64) and transcription inhibitors (KRAB) to specifically activate and inhibit target genes of interest. Our experimental results showed that the molecular sensors that we designed and constructed specifically sensed the endogenous signal molecules and then redirect the cancer related signal networks of cancer cells. In addition, corresponding logic gates were constructed to distinguish cancer cells from normal cells and redirect anticancer signal flows to trigger specific cancer immunotherapy. The constructed molecular sensors constructed specifically recognized the signal molecules within the cell and redirected the endogenous signal pathway to reprogram the fate of cancer cells.

Continuously tunable single-photon level nonlinearity with Rydberg state wave-function engineering

Extending optical nonlinearity into the extremely weak light regime is at the heart of quantum optics, since it enables the efficient generation of photonic entanglement and implementation of photonic quantum logic gate. Here, we demonstrate the capability for continuously tunable single-photon level nonlinearity, enabled by precise control of Rydberg interaction over two orders of magnitude, through the use of microwave-assisted wave-function engineering. To characterize this nonlinearity, light storage and retrieval protocol utilizing Rydberg electromagnetically induced transparency is employed, and the quantum statistics of the retrieved photons are analyzed. As a first application, we demonstrate our protocol can speed up the preparation of single photons in low-lying Rydberg states by a factor of up to∼40. Our work holds the potential to accelerate quantum operations and to improve the circuit depth and connectivity in Rydberg systems, representing a crucial step towards scalable quantum information processing with Rydberg atoms.

Modular Plasmonic Nanopore for Opto‐Thermal Gating

AbstractSolid‐state nanopore gating inspired by biological ion channels is gaining increasing traction due to a large range of applications in biosensing and drug delivery. Integration of stimuli‐responsive molecules such as poly(N‐isopropylacrylamide) (PNIPAM) inside nanopores can enable temperature‐dependent gating, which so far has only been demonstrated using external heaters. In this work, plasmonic resonators are combined inside the nanopore architecture with PNIPAM to enable optical gating of individual or multiple nanopores with micrometer resolution and a switching speed of a few milliseconds by thermo‐plasmonics effects. A temperature change of 40 kelvin per millisecond is achieved and demonstrates the efficacy of this method using nanopore ionic conductivity measurements that enable selective activation of individual nanopores in an array. Moreover, the selective gating of specific nanopores in an array can set distinct ionic conductance levels: low, medium, and high (i.e., “0,” “1,” and “2”), which can be exploited for logical gating with optical signal control. Such selective optical gating in nanopore arrays marks a breakthrough in nanofluidics, as it paves the way toward smart devices that offer multifunctional applications including biosensing, targeted drug delivery, and fluidic mixing.

Ultrafast Charge Transfer-Induced Unusual Nonlinear Optical Response in ReSe2/ReS2 Heterostructure.

Ultrafast charge transfer in van der Waals heterostructures can effectively engineer the optical and electrical properties of two-dimensional semiconductors for designing photonic and optoelectronic devices. However, the nonlinear absorption conversion dynamics with the pump intensity and the underlying physical mechanisms in a type-II heterostructure remain largely unexplored, yet hold considerable potential for all-optical logic gates. Herein, two-dimensional ReSe2/ReS2 heterostructure is designed to realize an unusual transition from reverse saturable absorption to saturable absorption (SA) with a conversion pump intensity threshold of approximately 170 GW/cm2. Such an intriguing phenomenon is attributed to the decrease of two-photon absorption (TPA) of ReS2 and the increase of SA of ReSe2 with the pump intensity. Based on the characterization results of X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, femtosecond transient absorption spectrum, Kelvin probe force microscopy, and density functional theory calculation, a type-II charge-transfer-energy level model is proposed combined with the TPA of ReS2 and SA of ReSe2 processes. The results reveal the critical role of ultrafast interfacial charge transfer in tuning the unusual nonlinear absorption and improving the SA of ReSe2/ReS2 under different excitation wavelengths. Our finding deepens the understanding of nonlinear absorption physical mechanisms in two-dimensional heterostructure materials, which may further diversify the nonlinear optical materials and photonic devices.

Dynamic Nanostructure-Based DNA Logic Gates for Cancer Diagnosis and Therapy.

DNA logic gates with dynamic nanostructures have made a profound impact on cancer diagnosis and treatment. Through programming the dynamic structure changes of DNA nanodevices, precise molecular recognition with signal amplification and smart therapeutic strategies have been reported. This enhances the specificity and sensitivity of cancer theranostics, and improves diagnosis precision and treatment outcomes. This review explores the basic components of dynamic DNA nanostructures and corresponding DNA logic gates, as well as their applications for cancer diagnosis and therapies. The dynamic DNA nanostructures would contribute to cancer early detection and personalized treatment.

Selective Detection of Divalent Cations (Cu2+, Zn2+, Pb2+) and Anions (SO42-, S2-, CO32-) Using a pH-Sensitive Multi-functional Schiff Base inNeutralMedium.

A new Schiff base-based multi-cation/anion probe (L) has been synthesized and characterized using HR-MS, FT-IR, 1H, and 13C NMR techniques. The Schiff base motif provides specific binding sites that detect cations and anions by generating distinct optical output signals upon interaction. A noticeable color change of the probe solution was observed from pale yellow to various shades of yellow upon adding cations such as Cu2+, Zn2+, and Pb2+ and anions such as CO32⁻, S2⁻, and SO42⁻. This color change results from forming complexes like M3L2 with metal ions. Whereas origin of color in presence of anion were attributed due to the deprotonation of acidic proton in the ligand. Moreover, the complexes formed by Zn2+, S2/CO32⁻ ion with L are fluorescent, enabling the detection of Cu2+ and SO42⁻ using the Stern-Volmer plot, with a limit of detection (LODs) of 8.48µM and 10.47µM, respectively. Additionally, increasing the pH of the probe solution above 8 reveals a significant enhancement of fluorescence intensity due to the deprotonation of phenolic -OH and amide -NH in the presence of hydroxide ions. This emission in the basic medium is quenched by Cu2+ ions and restored when Cu2+ is complexed with EDTA. A logic gate has also been constructed for understanding the TURN-OFF-TURN-ON mechanism involving Cu2+ ions and EDTA. Overall, the versatile performance of a single probe L opens up new possibilities as a multifunctional sensor, making it highly suitable for practical applications.

Translating weighted probabilistic bits to synthetic genetic circuits.

Synthetic genetic circuits in plants could be the next technological horizon in plant breeding, showcasing potential for precise patterned control over expression. Nevertheless, uncertainty in metabolic environments prevents robust scaling of traditional genetic circuits for agricultural use, and studies show that a deterministic system is at odds with biological randomness. We analyze the necessary requirements for assuring Boolean logic gate sequences can function in unpredictable intracellular conditions, followed by interpreted pathways by which a mathematical representation of probabilistic circuits can be translated to biological implementation. This pathway is utilized through translation of a probabilistic circuit model presented by Pervaiz that works through a series of bits; each composed of a weighted matrix that reads inputs from the environment and a random number generator that takes the matrix as bias and outputs a positive or negative signal. The weighted matrix can be biologically represented as the regulatory elements that affect transcription near promotors, allowing for an electrical bit to biological bit translation that can be refined through tuning using invertible logic prediction of the input to output relationship of a genetic response. Failsafe mechanisms should be introduced, possibly through the use of self-eliminating CRISPR-Cas9, dosage compensation, or cybernetic modeling (where CRISPR is clustered regularly interspaced short palindromic repeats and Cas9 is clustered regularly interspaced short palindromic repeat-associated protein 9). These safety measures are needed for all biological circuits, and their implementation is needed alongside work with this specific model. With applied responses to external factors, these circuits could allow fine-tuning of organism adaptation to stress while providing a framework for faster complex expression design in the field.

Investigation of metal-insulator-metal waveguides with elliptical-nanodisk resonator for high contrast ratio all-optical logic gates

Abstract This research focuses on the design and analysis of all-optical Exclusive OR(XOR), NOT, and OR logic gates based on metal-insulator-metal waveguides with elliptical-nanodisk resonators. The functionality of the proposed optical logic gates is determined by constructive and deconstructive signals which are applied to the input ports and control ports. To show the logic 0 (low) and logic 1 (high) output states, the limit of threshold transmission is 1.775 × 10−13 ∼0. The transmission (T) and contrast ratio (CR) are obtained to present the performance of the optical logic gates via the method of finite-difference time-domain. The maximum transmission is reached for the OR gate as 1.38 and the highest contrast ratio is 124.75 dB for the XOR and NOT logic gates. The designed logic devices are promising for improving more efficient optical signal information processing devices.

Selective Chromogenic Chemosensors for Arsenite Anion: A Facile Approach to Analyzing Arsenite in Honey, Milk, and Water Samples.

In this study, two chemosensors, N5R1 and N5R2, based on 5-(4-nitrophenyl)-2-furaldehyde, with varying electron-withdrawing groups, were synthesized and effectively employed for the colorimetric selective detection of arsenite anions in a DMSO/H2O solvent mixture (8 : 2, v/v). Chemosensors N5R1 and N5R2 exhibited a distinct color change upon binding with arsenite, accompanied by a spectral shift toward the near-infrared region (Δλmax exceeding 200 nm). These chemosensors established stability between a pH range 6-12. Among them, N5R2 displayed the lowest detection limit of 17.63 ppb with a high binding constant of 2.6163×105 M-1 for arsenite. The binding mechanism involved initial hydrogen bonding between the NH binding site and the arsenite anion, followed by deprotonation and an intramolecular charge transfer (ICT) mechanism. The mechanism was confirmed through UV and 1H NMR titrations, cyclic voltammetric studies, and theoretical calculations. The interactions between the sensor and arsenite anions were further analyzed using global reactivity parameters (GRPs). Practical applications were demonstrated through the utilization of test strips and molecular logic gates. Real water samples, honey, and milk samples were successfully analyzed by both chemosensors for the sensing of arsenite.

Shrinkable muscular crystal with chemical logic gates driven by external ion environment

Biomimetic chemical logic gates that can reversibly transform their shape and physical properties in response to their environment are an important research field. Most artificial chemical logic gates, however, rely on changes in the microscopic properties of molecules and ions in solution. Hence, developing chemical logic gates that influence macroscopic properties, such as crystal structures and magnetic and electrical properties, is essential for mimicking in vivo phenomena more accurately. Here, we develop a reset-set flip-flop circuit based on a single crystal that reversibly transforms in the presence of Ca2+ ions in aqueous solutions and is analogous to the chemical logic gate in muscles. During the crystal transformation, the lattice volume undergoes ~39% shrinkage, and the magnetic and electrical properties change considerably. Compared with existing products, the constructed crystalline system more closely resembles the function of actual muscles, which is promising for advancing the field of biomimetics.