A Fluorescent Aptamer Sensor for Detecting Golgi Protein 73 Based on Magnetic Ferroferric Oxide@Boron, Nitrogen-Doped Graphene Quantum Dots

Biotechnol Appl Biochem. 2025 Jun 8. doi: 10.1002/bab.70006. Online ahead of print.

Abstract

In this paper, a fluorescent aptamer sensor based on magnetic ferroferric oxide@boron, nitrogen-doped graphene quantum dots (Fe3O4@B,N-GQDs) was developed to detect Golgi protein 73 (GP73). GP73 aptamer (GP73Apt) functioned with Fe3O4@B,N-GQDs (Fe3O4@B,N-GQDs-GP73Apt) and was used as the fluorescent donor, while molybdenum disulfide (MoS2) with a large surface served as the fluorescent acceptor. The fluorescence of Fe3O4@B,N-GQDs-GP73Apt was quenched by MoS2 based on the fluorescence resonance energy transfer (FRET) principle. However, in the presence of GP73, Fe3O4@B,N-GQDs-GP73Apt could specifically bind to GP73, forming a Fe3O4@B,N-GQDs-GP73Apt-GP73 complex. This binding event caused Fe3O4@B,N-GQDs-GP73Apt to move away from the surface of MoS2, thus blocking the FRET process and recovering the fluorescence. Under optimal conditions, a linear relationship was established between the fluorescence recovery and the concentration of GP73 within the range of 10-1000 ng/mL (R2 = 0.9918), and the limit of detection was 7.37 ng/mL. Additionally, when the sensor was applied to test actual samples, the recovery rates were in the range of 98.80%-101.18%, and the relative standard deviations were between 0.29%-3.04%. These findings demonstrated the excellent detection performance of the proposed fluorescent aptamer sensor.

Keywords: fluorescence resonance energy transfer; fluorescent aptamer sensor; golgi protein 73; magnetic ferroferric oxide @boron, nitrogen‐doped graphene quantum dots; molybdenum disulfide.