  An astonishingly diverse biomolecular circuitry orchestrates the functioning
machinery underlying every living cell. These biomolecules and their circuits
have been engineered not only for various industrial applications but also to
perform other atypical functions that they were not evolved for - including
computation. Various kinds of computational challenges, such as solving
NP-complete problems with many variables, logical computation, neural network
operations, and cryptography, have all been attempted through this
unconventional computing paradigm. In this review, we highlight key experiments
across three different eras of molecular computation, beginning with molecular
solutions, transitioning to logic circuits and ultimately, more complex
molecular networks. We also discuss a variety of applications of molecular
computation, from solving NP-hard problems to self-assembled nanostructures for
delivering molecules, and provide a glimpse into the exciting potential that
molecular computing holds for the future.
