The application of CdTe/CdS in the detection of carcinoembryonic antigen by fluorescence polarization immunoassay.

A novel and portable strategy based on fluorescence polarization immunoassay (FPIA) using quantum dots (QDs) was described in this study for simple, rapid, and sensitive detection of carcinoembryonic antigen (CEA). Under optimal conditions, the sensor has a wide dynamic range (from 0.5 ng/mL to 200 ng/mL) and a good correlation. The limit of detection (LOD) is 0.21 ng/mL (S/N = 3). The sensor has been applied for detection of carcinoembryonic antigen in 10 human serum samples with the range of recovery from 92.1 % to 103.6 %. Furthermore, bioconjugation of the core-shell QDs with streptavidin (SA) has been successfully applied in immunofluorescent imaging of the human hepatocellular carcinoma (HEPG2) cell line. The experimental results demonstrated the successful application of QDs-based fluorescence polarization immunoassay for detection of target proteins of biomedical importance. This strategy shows great promise for clinical diagnoses and basic discovery with high sensitivity, good specificity, simple procedures and short analysis time.