Table 1.

Summary of sensing models developed here

Model	Coherent two-state dynamics	Coherent multistate dynamics (hence CR) after analyte binding	Analyte diffusion and coherent CR	Analyte diffusion and incoherent CR
Assumptions	Reversible coherent dynamics in the two-state approximation.	A localized electronic state produced by the analyte binding irreversibly relaxes to a dense manifold of states at the receptor–substrate interface.	A localized state irreversibly relaxes to two manifolds of states at the exposed surface of the receptor and at the receptor–substrate interface.	Thermal fluctuations of the atoms in the receptor lead to incoherent CR.
Special properties		Sensing exclusively based on quantum relaxation processes.	Quantum effects are incorporated in the CR between the state manifolds induced by each binding event.	Incoherent CR during the analyte diffusion erases the quantum effects. The binding of the analyte perturbs the energy differences between the two manifolds of states, thus leading to CR.
Results	A weaker coupling implies a higher sensitivity to the perturbation when the unperturbed states have similar energies.	The event of interest causes the electronic state relaxation (hence a signal in the actuator) or changes the properties of electronic relaxation produced by an external control mechanism or transient phenomenon. The timescale of the electronic relaxation characterizes the observed nanosensor output signal.	The equilibrium charge distribution between exposed surface of the receptor and receptor–substrate interface determines the signal, whereas the diffusion of the analyte dictates the timescale of the signal. Special conditions are required to apply this model to MOCSERs.	The model predicts that the actuator’s signal may increase or decrease with increasing length of the receptor molecules in a MOCSER.
Limits of applicability	Coupling to bulk states and thermal fluctuations that can break the assumption of coherent quantum dynamics are not included.	Incoherence that arises from thermal fluctuations is not included (hence needs to be negligible for the applicability of the model).	The coupling between the two manifolds of states that may induce decoherence is not included and would erase the information on the initial localization of the external perturbation.