Rapid and specific detection nanoplatform of serum exosomes for prostate cancer diagnosis

Tumor exosomes that inherit specific molecules from their parent cells are emerging as ideal biomarkers in cancer diagnostics. Most currently available exosome isolation and detection methods are time-consuming and non-specific; thus, rapid and specific exosome detection methods are needed both clinically and in research. Here, a dual-functional platform is reported composed of reversible conjunction and “off-on” signal responses. Fe 3 O 4 @SiO 2 @TiO 2 particles with high affinity were applied to capture exosomes, and model exosomes could be isolated from solution within 20 min with a capture efficiency of 91.5%. An “on-off” fluorescence response PSMA aptasensor was constructed with improved selectivity to detect tumor exosomes by recording the fluorescence intensity with λ ex/em = 557/580 nm. The standard curve for detecting tumor exosomes with the aptasensor was calculated as y = 371.7 x + 66.17, ranging from 0.05 to 1 × 10 4 particles/μL, with R 2 = 0.9737, and a detection limit of 5 × 10 2 particles/μL in solution. This method was successfully applied to clinical samples, and the results showed better performance in distinguishing prostate cancer patients and healthy samples than the traditional nanoparticle-tracking analysis (NTA) method. This rapid and accurate detection method for prostate cancer may aid in rapid clinical diagnosis. Graphical abstract Integrating quickly TiO 2 -based isolation with sensitive and specific “on-off” detection of PCa exosomes.