Nitrogen-Doped Graphene Quantum Dots@SiO2 Nanoparticles as Electrochemiluminescence and Fluorescence Signal Indicators for Magnetically Controlled Aptasensor with Dual Detection Channels

摘要: We proposed a facile method to prepare the nitrogen-doped graphene quantum dots (NGQDs) doped silica (NGQDs@SiO2) nanoparticles (NPs). The NGQDs@SiO2 NPs were further explored as versatile signal indicator for ochratoxin A (OTA) aptasensing by combination with electrochemiluminescence (ECL) and fluorescence (FL) detection. In this strategy, core-shell Fe3O4@Au magnetic beads (MBs) acted nanocarrier immobilize thiolated aptamer specific OTA, amino modified capture DNA (cDNA) was efficiently tagged NPs. multifunctional aptasensor thus fabricated assembly of onto surface MBs through high hybridization between cDNA. Upon OTA incubation, linked preferred form an aptamer-OTA complex, which resulted in partial release preloaded more molecules detection system, released into bulk solution less accumulated on electrode surface. This provided dual channel enriched solid-state ECL homogeneous FL assay exhibits wide dynamic range is reproducible due while possesses lower limit preferable using cheaper instrument. One can obtain preliminary screen from accurate result assay. Integrating virtues analytical modality, strategy well-balanced rapidity, sensitivity, range, making it promising other targets sequences.