Metal-Enhanced Fluorescence and FRET in Multilayer Core-Shell Nanoparticles

Table 2

Fluorescence lifetime data for CCP in solution and as CCP/SiO₂, CCP/Ag@SiO₂, and CCP/Ag@SiO₂@SiO₂ + FiTC nanoparticles (reprinted with permission from [40], Copyright 2011 American Chemical Society).

	𝜏 1; (ns)	𝐴 1; (%)	𝜏 2; (ns)	𝐴 2; (%)	𝜏 av; (ns)	𝜒^2
Free in solution^a	0.188	100			0.188	1.008
CCP/SiO2^b	0.119	100			0.119	1.003
CCP/Ag@SiO2^b	0.028	100			0.028	1.009
CCP/Ag@SiO2@SiO2 + FiTC^b	0.014	99.98	0.81	0.02	0.014	1.020

^a𝜆 _ex = 405 nm; 𝜆_em = 530 nm; ^b𝜆_ex = 405 nm; 𝜆_em = 490 nm.
Definition of headers: 𝜏₁, 𝐴₁, 𝜏₂, 𝐴₂ are the lifetime and amplitude values for the first and second fitting components, respectively; 𝜏_av is the averaged lifetime value and 𝜒² is the “goodness of fit” parameter.