(An) aptamer-based platform to identify target protein utilizing graphene oxide and hybridization chain reaction

Abstract

Herein, we developed a target protein detection platform based on the aptamer using graphene oxide and hybridization chain reaction techniques. This platform consists of one hairpin probe based on aptamer sequence that specifically binds to a target protein, and two hairpin probes that perform a hybridization chain reaction by triggering a single-stranded sequence exposed to a structural change in the aptamer probe's presence. Confirmation of the reaction results is designed to modify the G-quadruplex sequence within a hybridization chain reaction hairpin probe to form a G-quadruplex structure when a chain reaction occurs, and then measures fluorescence signals emitted by coupling with the fluorescent dye thioplavin T. For the verification of this technique, platelet-derived growth factors were selected as target proteins, and graphene oxide was used to suppress non-specific fluorescence signals and improve signal-to-noise ratio. As a result, the platelet-derived growth factor was detected with lmit of detection (LOD) of 4.53 pM, and the high selectivity was confirmed by successfully separating other proteins. As a result, the detection of platelet-derived growth factors within human serum was also conducted to demonstrate its practicality as a clinical analysis technology for cancer cell biosensor and molecular diagnosis.