An easy-operation aptasensor for simultaneous detection of multiple tumor-associated exosomal proteins based on multicolor fluorescent DNA nanoassemblies

As a promising liquid biopsy biomarker, exosomes have demonstrated great potential and advantages in the noninvasive tumor diagnosis. However, an accurate and sensitive method for tumors-associated exosomes detection is scarce. Herein, we presented an easy-operation aptasensor which simultaneously detect multiple exosomal proteins by using multicolor fluorescent DNA nanoassemblies (FDNs) and CD63 aptamer-modified magnetic beads (MNPs-AptCD63). In this system, the FDNs were firstly constructed by encapsulating different quantum dots (QDs) into rolling circle amplification (RCA) products that contained different aptamer sequences. Thus, the FDNs could selectively recognize the different exosomal proteins captured by the MNPs-AptCD63, and achieve the multiplex and sensitive detection according to the fluorescence of QDs. Benefiting from the signal amplification capacity and high selectivity of FDNs, this aptasensor not only could detect exosomes as low as 650 particles/μL, but also showed accurate analysis in clinical samples. In addition, we can also achieve point-of-care testing (POCT) due to the simple analysis steps and naked-eye observable fluorescence of QDs under the ultraviolet irradiation. We believe that our aptasensor could provide a promising platform for exosomes-based personalized diagnosis and precise monitoring of human health. [Display omitted] •This aptasensor has shortened analysis time and simplified analysis process by integrating the signal unit (QDs) and recognized unit (aptamer) into one nanoparticle.•The aptasensor showed high sensitivity by using FDNs and excellent anti-interference ability due to the magnetic isolation of MNPs-AptCD63.•This aptasensor could simultaneously quantify the multiple exosomal proteins, thus improving the accuracy of tumor diagnosis.