Abstract:
Objective To develop a biotin-streptavidin system (BAS)-mediated folate receptor (FR)-targeted quantum dot (QD) fluorescent probe and preliminarily validate the targeting ability and signal amplification effect of the probe.
Methods Streptavidin (SA) was covalently coupled with QD through the active ester method; the physical characteristics of the prepared QD-SA were verified. Biotinylated folate was synthesized through the carrier bovine serum albumin using the same method and then reacted with QD-SA to form the special probe. The probe was used to identify SKOV3 cells and FR-negative A549 cells to verify its targeting specificity. QD-SA was used as the contrast. SKOV3 cells were imaged using the BAS-mediated FR-targeted QD probe with a biotinylated folate incubation time of 1 or 4 h. Various reaction times were also tested between the probe and the QD-FA that was formed without BAS mediation.
Results The BAS-mediated FR-targeted QD probe specifically recognized FR-positive SKOV3 cells. The probe obtained higher fluorescent intensity after 4 h than after 1 h of biotinylated folate incubation. The BAS-mediated FR-targeted QD probe also had a stronger fluorescent signal than the QD-FA probe.
Conclusion The proposed probe presents a great potential in the early diagnosis of ovarian cancer because of its high specificity and sensitivity.