Molecules, semiconductors, light and information: Towards future sensing and computing paradigms

Over the last few years we have witnessed a great progress in the research devoted to unconventional computing - an unorthodox approach to information handling. It includes both novel algorithms and computing paradigms as well as completely new elements of circuitry: whole organisms (e.g., Physarum species), DNA, enzymes, various biomolecules, molecular and nanoparticulate materials. One of the biggest challenges in this field is the realisation of in-materio computing - i.e., the utilisation of properties of pristine materials, instead of high-tech structures - for advanced information processing. In this review we present recent achievements in the design of logic devices (binary, ternary and fuzzy) implemented in molecular and nanoscale components, photoelectrochemical chemosensing, photoactive memristive devices and reservoir computing systems. A common denominator for all these devices is the involvement of molecular species, semiconducting nanoparticles and light in information processing.