An immunofluorescence assay based on quantum dots determination of Alpha fetal protein: Immunofluorescence assay for AFP

Semiconductor quantum dots (QDs) have drawn considerable attention since its emergence because they have high brightness and a long luminous time. Our aim is to develop a new assay based on QDs to determine Alpha fetal protein (AFP) by immunofluorescence assay (IFA). Two different monoclonal antibodies of anti-AFP were labeled by QDs and the magnetic beads. After combination with AFP antigen, the fluorescence intensity of QDs was detected by the fluorospectrophotometer. The method was linear to 400 ng/mL AFP with a detection limit of 1.2 ng/mL. The intra-assay imprecision of two different level serums were 5.81% and 5.53%; the inter-assay imprecision values were 6.26% and 6.15%. The proposed method may be applied in the clinical lab.