Fig. 4

Fluorescence of Eu-VSOP. Fluorescence intensity of doped Eu-VSOP-7 (60 nmol/L) increased over time (measured every 2 min for 6 h; n = 3) with the HEE solution, while it drastically decreased after ~ 2 h with the DELFIA^® enhancer solution. The SD of the mean fluorescence signal for HEE variates between 0.8 and 9.4% and between 0.84 and 5.86% for DELFIA^®