A molecular logic gate is a molecule that performs a logical operation based on one or more physical or chemical inputs and a single output. The field has advanced from simple logic systems based on a single chemical or physical input to molecules capable of combinatorial and sequential operations such as arithmetic operations (i.e. moleculators and memory storage algorithms). Molecular logic gates work with input signals based on chemical processes and with output signals based on spectroscopic phenomena.
Logic gates are the fundamental building blocks of electrical circuits. They can be used to construct digital architectures with varying degrees of complexity by a cascade of a few to several million logic gates. Logic gates are essentially physical devices that produce a singular binary output after performing logical operations based on Boolean functions on one or more binary inputs. The concept of molecular logic gates, extending the applicability of logic gates to molecules, aims to convert chemical systems into computational units. Over the past three decades, the field has evolved to realize several practical applications in molecular electronics, biosensing, DNA computing, nanorobotics, and cell imaging, among others.