Construction of magnetically separated quantum dot fluorescent aptasensor and its application in MUC1 detection

Abstract

Tumor markers, produced due to genetic alterations, are vital for cancer detection, diagnosis, treatment, and prognosis. Quantum dots (QDs), a novel luminescent nanomaterial, exhibit unique chemical and optical properties. Integrating QDs with biosensing technology enables highly sensitive and selective detection of target molecules, offering significant potential in biomedicine. This study developed a g-CNQDs-Apt/WS₂/Fe₃O₄ magnetically separated fluorescent aptasensor based on fluorescence resonance energy transfer (FRET) for detecting the tumor marker mucin 1 (MUC1). Magnetic separation enhanced fluorescence recovery, reduced background interference, and improved the linear detection range for MUC1. The system demonstrated a strong linear correlation (R² = 0.9926) between MUC1 concentration and fluorescence recovery, with a detection limit of 0.89 ng/mL, relative standard deviations of 3.24%–4.68%, and recoveries of 94.99%–112.39%. These findings provide valuable insights for developing fluorescent aptasensors for other tumor markers and biomedical targets.