Point-dipole model for metal-enhanced fluorescence

A simple analytical model for calculating the Purcell factor in metal-enhanced fluorescence (MEF) may replace its difficult precise calculations involving either the Green function of a plasmonic nanoantenna (NA) or the resonator mode volume. The model considers the NA as a point dipole. It was previously introduced conceptually, but was applied for only two special cases having no practical importance for nanosensing. In this Letter, we show that this model has a predictive power for practical schemes of MEF which is an important tool of nanosensing.