A cost-effective and novel hybrid biosensor using the combination of antibody and DNA aptamer was developed for the early diagnosis of breast cancer. 1,1’-oxalyldiimidazle chemiluminescence (ODI-CL) was applied as a detector of the hybrid biosensor. The antibody immobilized on the surface of polystyrene strip-well rapidly captured the carcinoembryonic antigen (CEA), which is a breast cancer marker, within 20 min at 37 C. DNA aptamer-linked hemin aptamer was added in the strip-well washed with PBST. After a 1-hr incubation of mixuture in the strip-well at 37 C, hybrid complex (antibofy-CEA-DNA aptamer-linked hemin aptamer) was formed. Hemin was added in the strip-well to form horseradish peroxidase (HRP)-mimicking DNAzyme (complex of hemin and hemin aptamer) for a 5-min incubation at 37 C. Substrates (e.g., Amplex Red, H2O2) of HRP-mimicking DNAzyme added in the strip-well after the washing with PBST was incubated for 10 min at room temperature (21 ± 2 C) to produce resorufin, which is a luminophore. Finally, CL emission was observed when H2O2 and ODI were consecutively added in the strip-well. The brightness of CL was proportionally enhanced with the increase of CEA. The limit of detection (LOD = 3/slope) of hybrid biosensor was as low as 0.55 ng/ml.
Journal: TechConnect Briefs
Volume: 1, Advanced Materials: TechConnect Briefs 2015
Published: June 14, 2015
Pages: 298 - 301
Industry sector: Advanced Materials & Manufacturing
Topic: Nanoparticle Synthesis & Applications