Biomolecular Filters for Improved Separation of Output Signals in Enzyme Logic Systems Applied to Biomedical Analysis

Biomolecular logic systems processing biochemical input signals and producing "digital" outputs in the form of YES/NO were developed for analysis of physiological conditions characteristic of liver injury, soft tissue injury and abdominal trauma. Injury biomarkers were used as input signals for activating the logic systems. Their normal physiological concentrations were defined as logic-0 level, while their pathologically elevated concentrations were defined as logic-1 values. Since the input concentrations applied as logic 0 and 1 values were not sufficiently different, the output signals being at low and high values (0, 1 outputs) were separated with a short gap making their discrimination difficult. Coupled enzymatic reactions functioning as a biomolecular signal processing system with a built-in filter property were developed. The filter process involves a partial back-conversion of the optical-output-signal-yielding product, but only at its low concentrations, thus allowing the proper discrimination between 0 and 1 output values

Optimization of Enzymatic Biochemical Logic for Noise Reduction and Scalability: How Many Biocomputing Gates Can Be Interconnected in a Circuit?

We report an experimental evaluation of the "input-output surface" for a biochemical AND gate. The obtained data are modeled within the rate-equation approach, with the aim to map out the gate function and cast it in the language of logic variables appropriate for analysis of Boolean logic for scalability. In order to minimize "analog" noise, we consider a theoretical approach for determining an optimal set for the process parameters to minimize "analog" noise amplification for gate concatenation. We establish that under optimized conditions, presently studied biochemical gates can be concatenated for up to order 10 processing steps. Beyond that, new paradigms for avoiding noise build-up will have to be developed. We offer a general discussion of the ideas and possible future challenges for both experimental and theoretical research for advancing scalable biochemical computing

Realization and Properties of Biochemical-Computing Biocatalytic XOR Gate Based on Enzyme Inhibition by a Substrate

We consider a realization of the XOR logic gate in a process biocatalyzed by an enzyme (here horseradish peroxidase: HRP), the function of which can be inhibited by a substrate (hydrogen peroxide for HRP), when the latter is inputted at large enough concentrations. A model is developed for describing such systems in an approach suitable for evaluation of the analog noise amplification properties of the gate. The obtained data are fitted for gate quality evaluation within the developed model, and we discuss aspects of devising XOR gates for functioning in "biocomputing" systems utilizing biomolecules for information processing

A three-valued photoelectrochemical logic device realising accept anything and consensus operations

A new application of a hybrid material exhibiting the photoelectro-chemical photocurrent switching (peps) effect in a three-valued logic device is reported. In contrast to other similar peps-based systems, the one described here is capable of performing basic ternary logic operations: gullibility and consensus

Ground and excited state properties of alizarin and its isomers

Four different alizarin dyes are studied with optical, electrochemical and quantum-chemical techniques. Despite structural similarities they show marked differences regarding both ground and excited state properties. All these dyes are characterized with strong HOMO–LUMO transitions of internal charge transfer character. These transitions, however, show different reorganization energies due to involvement of intramolecular proton transfer processes. Differences in charge redistribution upon excitation may lead to different photochemical reactivity of these species and also to different behavior in dye-sensitized solar cells and other devices.Fil: Mech, Justyna. University Of Science And Technology; PoloniaFil: Grela, Maria Alejandra. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Szacilowski, K.. University Of Science And Technology; Polonia. Jagiellonian University; Poloni

Ligand and medium controlled photochemistry of iron and ruthenium mixed-ligand complexes: prospecting for versatile systems.

Selected Fe and Ru systems, whose photochemical behaviour is sensitive to numerous parameters, are presented. These systems, containing multiple species in equilibrium, are versatile enough to be adapted to special tasks and may also be used to model the phenomena and mechanisms occurring in nature. The role of various parameters is analysed and principal emphasis is given to the ligand sphere influence on the nature of the excited state and thereby on the photochemical mode. This is crucial in the case of Fe(II) complexes of the type [Fe(CN)5L]n-, whereas in the carbolyl–cyclopentadienyl complexes, represented by [cpRu(CO)2]2, the nature of the excited state is of less importance than for pentacyanoferrates( II). The photochemistry of the carbonyl–cyclopentadienyl complexes is more susceptible to the impact of the medium and the role of the secondary processes is more significant