@Au MNPs serve a dual functional role: (i) facilitating rapid and efficient magnetic isolation of target-bound UCNPs from human urine, thereby reducing matrix-derived background interference, and (ii) acting as localized plasmonic nanoantennas that enhance UCNPs upconversion luminescence through near-field electromagnetic coupling. By leveraging this synergistic design, the nanoplatform exhibits an exceptionally broad linear dynamic range (2.5-500 aM), an ultralow detection limit of 0.8 aM, and outstanding molecular selectivity. Clinical validation using deidentified, prospectively collected urine specimens from patients and healthy donors demonstrates that the assay accurately stratifies clinical status. In summary, this work introduces a clinically translatable nanoplatform that uniquely integrates plasmonic signal amplification, magnetic purification of native biofluids, and direct urinary miRNA analysis, thereby establishing a paradigm for noninvasive, early stage BC diagnosis and providing a versatile framework for next-generation miRNA-based cancer diagnostics.
Zhang et al. (Wed,) studied this question.