An Enzyme-Based Half-Adder and Half-Subtractor with a Modular Design.

A half-adder and a half-subtractor have been realized using enzymatic reaction cascades performed in a flow cell device. The individual cells were modified with different enzymes and assembled in complex networks to perform logic operations and arithmetic functions. The modular design of the logic devices allowed for easy re-configuration, enabling them to perform various functions. The final output signals, represented by redox species [Fe(CN)6 ](3-/4-) or NADH/NAD(+) , were analyzed optically to derive the calculation results. These output signals might be applicable in the future for actuation processes, for example, substance release activated by logically processed signals.

Structure-to-process design framework for developing safer pesticides.

Rational design of pesticides with tunable degradation properties and minimal ecotoxicity is among the grand challenges of green chemistry. While computational approaches have gained traction in predictive toxicology, current methods lack the necessary multifaceted approach and design-vectoring tools needed for system-based chemical development. Here, we report a tiered computational framework, which integrates kinetics and thermodynamics of indirect photodegradation with predictions of ecotoxicity and performance, based on cutoff values in mechanistically derived physicochemical properties and electronic parameters. Extensively validated against experimental data and applied to 700 pesticides on the U.S. Environmental Protection Agency's registry, our simple yet powerful approach can be used to screen existing molecules to identify application-ready candidates with desirable characteristics. By linking structural attributes to process-based outcomes and by quantifying trade-offs in safety, depletion, and performance, our method offers a user-friendly roadmap to rational design of novel pesticides.