Molecular sensors, often referred to as chemosensors or probes, are molecular or supramolecular structures designed to detect specific analytes by converting molecular recognition events into measurable signals. Unlike traditional macroscopic instruments, these sensors operate at the fundamental limit of chemical interaction, relying on host–guest chemistry to monitor chemical species in real-time within complex environments like biological tissues or waste effluents.

Fundamental Design and Mechanisms

1. Recognition Moiety (Receptor): The "host" unit that selectively binds the specific analyte ("guest") through non-covalent forces such as hydrogen bonding or electrostatic attraction.

2. Signaling Moiety (Transducer): The unit responsible for converting the binding event into a physical signal, most commonly optical (fluorescence ...