One-step Circulating Tumor DNA Microfluidic Sensing Based on Toehold-mediated Entropy-driven Bipedal DNA Walker and Dendritic Hybridization Chain Reaction
10.19756/j.issn.0253-3820.231448
- VernacularTitle:基于立足点介导的熵驱动双足DNA步行器及树枝状杂交链式反应的一步式循环肿瘤DNA微流控传感研究
- Author:
Mei YANG
1
;
Yu FU
;
He ZHANG
;
Wen-Jie MA
;
Yu-Hao DOU
;
Xin FU
;
Man-Xia LI
;
Chao-Ran ZENG
Author Information
1. 湖南工程学院材料与化工学院,湖南省环境催化与废弃物再生化重点实验室,湘潭411104
- Keywords:
DNA walker;
Entropy-driven strand displacement reaction;
Microfluidic chip;
8-17 DNAzyme;
Dendritic hybridization chain reaction
- From:
Chinese Journal of Analytical Chemistry
2024;52(11):1755-1765
- CountryChina
- Language:Chinese
-
Abstract:
Circulating tumor DNA (ctDNA) in blood,present at low abundance,serves as a critical biomarker for cancer. Precise detection of ctDNA is of great significance for early diagnosis,disease monitoring,and prognosis evaluation. In this study,a microfluidic chip-based entropy-driven bipedal DNA walker combined with dendritic hybridisation chain reaction was designed as a cascade signal amplification strategy for detection of ctDNA in blood in a microfluidic chip. In the presence of the target,toehold A interacted with target and triggerd a bidirectional strand displacement reaction with the aid of fuel strand F,thereby releasing the target and the 8-17 DNAzyme active centre. Among them,the released target was recycled in a new round of entropy-driven chain replacement reaction. Meanwhile,8-17 DNAzyme active center activated by Pb2+would act on the cleavage site of the substrate hairpin at the microbead surface,exposing the capture probes on the surface of the microbead. The numerous capture probes induced a dendritic hybridization chain reaction,which resulted in fluorescent signals being concentrated on the surface of the microbeads. With the breast cancer mutant gene PIK3CAE545K as the target model,under the optimal experimental conditions,the linear range of sensor was 50-10000 fmol/L,the detection limit was 0.94 fmol/L (LOD,3σ),and the regression equation was y=31.65 lgCT+474.08 (CT is the concentration mutant gene PIK3CAE545K sequence,fmol/L). This method showed spiked recoveries between 98.8％ and 106.5％ when applied to detection of mutant gene PIK3CAE545K in human serum. Characterized by its sensitivity,specificity,anti-interference capability,high throughput,and one-step operation,this method was ideally suited for the rapid analysis of complex samples.
