Gold Nanoparticles-Based Multipedal DNA Walker for Ratiometric Detection of Circulating Tumor Cell

Abstract

Sensitive and accurate quantification of circulating tumor cell (CTC) can provide new insights for early diagnosis and prognosis of cancers. Herein, we have developed a multipedal DNA walker for ultrasensitive detection of CTC for the first time. Generally, a number of walker strands are simply modified on gold nanoparticle (AuNPs). The integrated aptamer sequence can specially interact with the transmembrane receptor protein of CTC and facilitate the enrichment of AuNPs on the surface of cells. After a low speed centrifugation, the complex of CTC and AuNPs could be precipitated and the supernate represents decreased UV–vis absorbance response of AuNPs. On the other hand, since multiple walker strands are modified on a single AuNP, hybridization with several tracks on the electrode occurs simultaneously for the following nicking endonuclease-catalyzed cleaving. Experimental results verify that the rate of multipedal walking is much faster. In addition, TCEP-mediated electrochemical amplification is employed to further enhance the electrochemical signal. By comparing the variations of electrochemical and UV–vis absorbance responses, ultrahigh sensitivity for CTC assay is achieved. The limit of detection is down to 1 cell/mL. The results of selectivity confirmation and blood sample test are also satisfactory. This AuNPs-based multipedal DNA walker offers a speedy analysis of CTC and shows great potential use for early clinical diagnosis and treatment of cancers.

Rapid measurement of waterborne bacterial viability based on difunctional gold nanoprobe

“…Nucleic acids have been reported to induce the aggregation of GNPs to develop a color-changing reaction. 36–38 These results demonstrated the feasibility of the proposed method in measuring bacterial viability.…”

Recent Advances in Aptamer-Based Biosensors for Global Health Applications

“…For instance, a cell-SELEX-originated EC aptasensor was developed by Shangguan et al (96) to identify CCRF-CEM (leukemia) cells and used Ramos (human Burkitt's lymphoma) cells as experimental controls. Other groups fabricated EC aptasensors to detect CTCs from serum samples with a LOD of 1 to 100 cells/mL and from clinical samples with a LOD of 3 cells/mL (97)(98)(99). In addition, they conjugated a TD05 aptamer derived by the cell-SELEX process with magnetic nanocomposites, which exhibited specific binding capability to Ramos cells in the presence of other CTCs such as A549 (lung), MCF-7 (breast), and SKBR3 (breast) (99).…”

Detection and clinical significance of circulating tumor cells in colorectal cancer

“…High sensitivity and anti-interference ability. DNA probes ALL > 96.3 – – [ 43 ] Biophysical Properties Microfluidic A spiral microchannel with inherent centrifugal force. Taking advantage of two phenomena: Dean migration and inertial focusing.…”

“…This saccharide-sensitive biomimetic microplatform could release CTCs via a molecular exchange mechanism with low damage and achieved high cell capture (85%) and release (93%) efficiencies. Peng et al developed a gold nanoparticle-based multiple DNA walker for the ultrasensitive detection of CTCs for the first time (capture rate > 96.3%) [ 43 ]. By modifying a number of walker strands on gold nanoparticles (AuNPs), the integrated aptamer sequence can specifically bind to the transmembrane receptor protein of CTCs.…”