1.
Ultrasensitive Nanopore Sensing of Mucin 1 and Circulating Tumor Cells in Whole Blood of Breast Cancer Patients by Analyte-Triggered Triplex-DNA Release.
Sun, K, Chen, P, Yan, S, Yuan, W, Wang, Y, Li, X, Dou, L, Zhao, C, Zhang, J, Wang, Q, et al
ACS applied materials & interfaces. 2021;(18):21030-21039
Abstract
The characterization of circulating tumor cells (CTCs) by liquid biopsy has a great potential for precision medicine in oncology. Here, a universal and tandem logic-based strategy is developed by combining multiple nanomaterials and nanopore sensing for the determination of mucin 1 protein (MUC1) and breast cancer CTCs in real samples. The strategy consists of analyte-triggered signal conversion, cascaded amplification via nanomaterials including copper sulfide nanoparticles (CuS NPs), silver nanoparticles (Ag NPs), and biomaterials including DNA hydrogel and DNAzyme, and single-molecule-level detection by nanopore sensing. The amplification of the non-DNA nanomaterial gives this method considerable stability, significantly lowers the limit of detection (LOD), and enhances the anti-interference performance for complicated samples. As a result, the ultrasensitive detection of MUC1 could be achieved in the range of 0.0005-0.5 pg/mL, with an LOD of 0.1 fg/mL. Moreover, we further tested MUC1 as a biomarker for the clinical diagnosis of breast cancer CTCs under double-blind conditions on the basis of this strategy, and MCF-7 cells could be accurately detected in the range from 5 to 2000 cells/mL, with an LOD of 2 cells/mL within 6 h. The detection results of the 19 clinical samples were highly consistent with those of the clinical pathological sections, nuclear magnetic resonance imaging, and color ultrasound. These results demonstrate the validity and reliability of our method and further proved the feasibility of MUC1 as a clinical diagnostic biomarker for CTCs.
2.
[Separation of proteins on microchip electrophoresis and its comparison with DNA migration].
Liu, C, Xu, X, Zhang, J, Chen, J
Se pu = Chinese journal of chromatography. 2010;(3):296-300
Abstract
The efficient separation of six standard proteins on a home-made poly (dimethylsiloxane) microchip with an auto-deducting background diode laser induced fluorescence detector was accomplished within 6.4 min under the sieving matrix of 10 g/L hydroxyethyl cellulose (HEC), 1 g/L sodium dodecyl sulphonate (SDS), 40 mmol/L phosphate buffer at pH 7.0. The experimental results showed that the reproducibility of protein separation was satisfactory and the relative standard deviations (RSDs) of protein migration time were less than 10%. The migration times of the proteins are analyzed by a quantitative mathematical model of deoxyribonucleic acid (DNA) proposed by ourselves previously. The results showed that the migration character of SDS-protein complexes was similar with DNA. However, the linear relationships between the mobilities of SDS-protein complexes and their relative molecular mass as well as electric field strength became worse, which indicated the mathematical model for DNA separation should be revised before it is used for protein separation.