A homogeneous digital biosensor for circulating tumor DNA by the enumeration of a dual-color quantum dot complex. Issue 9 (31st March 2021)

• Record Type: Journal Article
• Authors: Liu, Xiaojun; Wu, Zhangjian; Lin, Xinyi; Bu, Wei; Qin, Lei; Gai, Hongwei
• Is Part Of: Analyst. Volume 146:Issue 9(2021)
• Page Start: 3034
• Page End: 3040
• Publication Date: 2021-03-31
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/d1an00299f
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : The one-step quantification of ctDNA was achieved by identifying and counting target-induced two-color QD aggregates. Abstract : Monitoring ctDNA in blood is important for cancer management. Here, a one-step single particle counting approach was developed for directly quantifying ctDNA in plasma. Hairpin DNA containing a triple helix stem was immobilized onto QD 585 as a probe. The hairpin was opened by the target, and therefore hybridized with assistant DNA on QD 655, resulting in an aggregate of QD 585 and QD 655. The two-color QD aggregate was regarded as the target. Observed under a single particle transmission grating-based spectral microscope, the two-color QD aggregate was distinguished by a unique spectral pattern of two first-order streaks, and it was counted. The difference in the responses of the probes to perfect-match DNA, single-base mismatch DNA, and non-match DNA indicated that the probe had sufficient single-base discrimination capabilities. The success in plasma recovery tests demonstrated the feasibility of carrying out the direct detection of ctDNA in plasma.