Table 1. Some physicochemical parameters of Eu-DTPA and AuNC probes.

Parameters	Eu-DTPA	AuNC@GSH	AuNC@BSA
MA (g/mol)	560.54	1.4 × 104	7.1 × 104
Particle core diameter (nm) (TEM)	—	2.1 ± 0.5	2.0 ± 0.4
Volume weighted hydrodynamic diameter (nm)	0.902	6.0 ± 1.03	12.1 ± 0.33
ζ potential (mV)	—	−1.47 ± 4.96	−7.89 ± 4.38
DAB (m2/S)1	3.36 × 10−10	1.15 × 10−10	6.68 × 10−11

¹Parameters calculated using the Polson’s equation: whereV_A is the volume of solute probe; μ_B and M_B are the viscosity and molar mass of the solvent water, respectively; T is the absolute temperature.

²The diameter of Eu-DTPA was calculated using HyperChem software.

³Data were from DLS measurement (Figure S5).