A MoS₂–MWCNT based fluorometric nanosensor for exosome detection and quantification

Abstract

A MoS2-MWCNT based fl uorometric nanosensor for exosome detection and quantifi cationExosome detection and quantifi cation as an invaluable source of biomarkers can off er a non-invasive method for the early detection of diseases such as cancer. This work shows an effi cient and cost-eff ective method to quantify sub-populations of exosomes based on a fl uorometric technique. Utilizing multiwall carbon nanotubes coated with molybdenum disulfi de (MoS2-MWCNT) as a fl uorescence quenching material and an exosome protein biomarker (CD63) as a target element, this work demonstrates a highly selective mechanism to quantify exosomes. This new approach involves minimal complexity and is amenable to exosome biomarkers of interest.Circulating exosomes in body fluids are involved in many diseases and have important roles in pathophysiological processes. Specifically, they have emerged as a promising new class of biomarkers in cancer diagnosis and prognosis because of their high concentration and availability in a variety of biological fluids. The ability to quantitatively detect and characterize these nano-sized vesicles is crucial to make use of exosomes as a reliable biomarker for clinical applications. However, current methods are mostly technically challenging and time-consuming which prevents them from being adopted in clinical practice. In this work, we have developed a rapid sensitive platform for exosome detection and quantification by employing MoS 2 -multiwall carbon nanotubes as a fluorescence quenching material.This exosome biosensor shows a sensitive and selective biomarker detection. Using this MoS 2 -MWCNT based fluorometric nanosensor to analyze exosomes derived from MCF-7 breast cancer cells, we found that CD63 expression could be measured based on the retrieved fluorescence of the fluorophore with a good linear response range of 0-15% v/v. In addition, this nanosensing technique is able to quantify exosomes with different surface biomarker expressions and has revealed that exosomes secreted from MCF-7 breast cancer cells have a higher CD24 expression compared to CD63 and CD81.

Recent Progress on the Isolation and Detection Methods of Exosomes

“…The recognition and analysis of exosomes are the premise and guarantee in clinical research. [40] Therefor, the quantitative analysis of exosomes is of great significance. In order to improve the efficiency, sensitivity and reliability of exosomes analysis, many researchers proposed new analysis methods by specific recognition of exosomes, such as nucleic acid information, specific proteins, lipid recognition, surface modification recognition and overall recognition, etc., as shown in Figure 3.…”

“…Previous researches found that exosomes had an important impact on tumorigenesis, tumor metastasis and targeted therapy. The recognition and analysis of exosomes are the premise and guarantee in clinical research [40] . Therefor, the quantitative analysis of exosomes is of great significance.…”

Advanced Nanotechnologies for Extracellular Vesicle‐Based Liquid Biopsy

“…The fluorescent antibodies would detach from MWCNTs when they bind to EVs, providing an LoD of 1480 EVs μL −1 . [113] In addition to fluorescence quenching based on carbon nanostructures, nucleic acid base pairing can also control fluorescent signals. A molecular beacon is a hairpin-shaped single-stranded DNA with an internally quenched fluorophore.…”

Nanoparticle-based biosensors for detection of extracellular vesicles in liquid biopsies

“…6b). 139,173,[176][177][178] Finally, polymeric NPs such as lanthanide chelate-doped polystyrene beads are also being used as sensing platforms. Islam et al used these NPs with long-lifetime fluorescence when compared with the fluorescence of highly effective markers, such as europium, to develop a NP-based time resolved fluorescence immunoassay (NP-TRFIA).…”