pH-Sensitive Dye-Based Nanobioplatform for Colorimetric Detection of Heterogeneous Circulating Tumor Cells

Abstract

The efficient capture and sensitive detection of circulating tumor cells (CTCs) play a vital role in cancer diagnosis and prognosis. However, CTCs in the peripheral blood are very rare and heterogeneous, which make them difficult to isolate and detect. Herein, a novel colorimetric nanobioplatform was successfully developed for the highly efficient capture and highly sensitive detection of heterogeneous CTCs, which consisted of two parts: the multivalent aptamer-modified gold nanoparticles as the capture unit and two kinds of aptamer-functionalized pH-sensitive allochroic dyes (thymolphthalein and curcumin) @ molybdenum disulfide nanoflakes (MoS 2 NFs) acting as the visual simultaneous detection of heterogeneous CTCs. Using MCF-7 and HeLa cells as the CTC models, the capture unit can effectively isolate the CTCs due to the multivalent probe with improved affinity. The two allochroic dyes can display obvious color changes under alkaline conditions (pH 12.5) in the presence of MCF-7 and HeLa cells, which provided a rapid and sensitive strategy for visualizing simultaneous detection of heterogeneous CTCs as low as 5 cells mL −1 . This nanoplatform possessed a high sensitivity toward CTC detection owing to high dye loading capacity of MoS 2 NFs and allochroic dyes with excellent pH sensitivity. It can successfully distinguish and quantitatively detect the targeted heterogeneous CTCs from numerous interfering cells in diluted whole blood. It can also be used to detect CTCs from lysed blood samples from cancer patients, indicating promising application for cancer diagnosis.

Recent Development of Nanomaterials-Based Cytosensors for the Detection of Circulating Tumor Cells

“…Nanomaterials with a large surface area can load plenty of chromogenic compounds and controllably release them for signal amplification. A pH-sensitive allochroic dye-based nanobioplatform was proposed for simultaneous capture and colorimetric detection of two heterogeneous CTCs (MCF-7 and HeLa) [96]. As shown in Figure 4, polyacrylic acid (PAA)-modified molybdenum disulfide nanoflakes (MoS 2 NFs) were utilized to load two kinds of aptamers (SYL3C and C−9S) and pH indicators (thymolphthalein (TP) and curcumin (CUR)).…”

What the Microscale Systems “See” In Biological Assemblies: Cells and Viruses?

“…Cancer is considered one of the most threatening diseases to human beings, and various treatment approaches have been utilized in the clinical diagnosis and therapy. − Because circulating tumor cells (CTCs) can provide sufficient information related to the cancer metastasis degree, the CTC assay is helpful for early cancer diagnosis. − CTCs are rare cells that exist in blood, and it is important to develop methods for enriching cells with high recovery. − Single-cell separation techniques have attracted increasing attention. , Microfluidic devices are considered an efficient technique for single-cell analysis. − Traditional cell isolation on a single chip involves complicated operation processes. Novel integrated microchips were designed to analyze CTCs. , For instance, an integrated microchip was developed for the efficient capture, noninvasive release, and mutation analysis of CTCs (Figure A).…”

Aptamer Embedded Arch-Cruciform DNA Assemblies on 2-D VS2 Scaffolds for Sensitive Detection of Breast Cancer Cells

“…Therefore, it is necessary to develop alternative molecular biological methods with high sensitivity, high accuracy and low cost for breast cancer diagnosis. There are numerous methods to detect MCF-7, including electrochemistry [15], electrochemiluminescence [16], colorimetry [17] and photoelectrochemical methods [18]. Aptamers, which are single-stranded DNA or RNA analogues to antibodies [19], have been attracting a lot of interest due to their advantages over traditional recognition molecules.…”