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A New Electrochemical Biosensor for Early Cancer Detection

The novel biosensor can detect exosomes with high accuracy and sensitivity, overcoming the limitations of previous quantitative technologies.

Lung cancer is the leading cause of cancer-related deaths worldwide. Early monitoring and diagnosis of cancer is key to improve patient survival rate. Liquid biopsy was presented as a ground-breaking tool for early cancer screening as it is non-invasive and can fully represent biological information about cancer cells or tissues.

It is known that exosomes, which are membrane-bound extracellular vesicles, have a lot of potential as a biomarker for early cancer diagnosis and to monitor highly metastatic cancer cells. These small extracellular vesicles were derived from tumour cells and are around 30-150 nm in size that can be detected by electrochemical biosensors. Electrochemical biosensors might be thought of as an appropriate analytical platform for exosome measurement because they are highly sensitive, selective, have a broad linear range, and are inexpensive.

Published in Biosensors and Bioelectronics, a team of scientists at the Suzhou Institute of Biomedical Engineering and Technology (SIBET) of the Chinese Academy of Sciences proposed a unique electrochemical biosensor for the sensitive identification and detection of target exosomes. The biosensor exhibited a wide linear range, high sensitivity for exosome sensing, and satisfactory repeatability.

Here, the team chose MXene nanosheets, a two-dimensional material with a large surface area, high electrical conductivity, and catalytic ability, as the components of MXene membrane preparation via simple vacuum filtration. Gold nanoarrays were then introduced and grown on the MXene membranes in situ.”

“The obtained combination of MXene membrane showed excellent conductivity, a large active site for aptamer immobilisation, and accelerated charge transfer,” said You Qiannan, the first author of the study and doctoral candidate from SIBET.

The composite membrane modified by EpCAM-recognised aptamer can specifically capture target exosomes. The target exosomes anchored with CD63 aptamer could fill unbound active sites, which raises the biosensor’s accuracy and sensitivity.

The team’s gold-MXene membrane platform-based biosensor used the features of large-scale preparation and MXene membrane reducibility to achieve good accuracy and stability in exosome determination. This work expands the use of two-dimensional materials in the field of biosensing and offers a novel platform with great sensitivity for precise exosome detection. [APBN]

Source: You et al. (2022). Hierarchical Au nanoarrays functionalized 2D Ti2CTx MXene membranes for the detection of exosomes isolated from human lung carcinoma cells. Biosensors and Bioelectronics, 114647.