Figure 5.

a) Calibration curve for the CEA assay in synthetic saliva based on Eu₂O₃ NCs through TRPL assay. b) Correlation of CEA values measured using Eu₂O₃ NCs and commercial Eu³⁺‐DTTA DELFIA kit for 20 human saliva samples. c) Correlation of CEA values between saliva and serum samples from 33 volunteers, measured by Eu₂O₃ NCs based bioassay system. d) Mean CEA levels (ng mL⁻¹) in serum and saliva samples of healthy people and oral cancer patients, respectively. All the saliva and serum samples were diluted ten times with 0.1 m PBS (pH 7.4) for the assay. Three independent experiments were carried out to yield the average value and deviation. The experiments involving human subjects were approved by the Animal Ethics Committee of Fujian Medical University.