Single Input–Single Output Systems
Boolean YES and NOT logic gates are the simplest switchable cases with single input and single output, whereas PASS 1 and PASS 0 gates are the constant versions. Molecular YES and NOT gates which are driven by a variety of (bio)chemical inputs are collected, classified and (in many cases) quantified. These gates contain receptor sites that bind reversibly with input species. Counterparts involving irreversible interactions between device and input are also included. Less tangible entities like electric voltage, temperature and light dose also serve as inputs to a substantial number of YES and NOT gates.