Cutting-Edge Aptasensing Approaches for Electrochemical Detection of Exosomes Utilizing MXenes

Abstract

Herein, the basic properties, composition, and isolation methods for the separation of exosomes are described, since they can be a rich source of disease biomarkers. Then an introduction to MXenes, a novel class of 2D nanomaterials with interesting properties applicable in numerous fields including biosensing is provided. Also, aptamers are described as an alternative to antibodies for the robust biorecognition of analytes of interest. The final part of the article gives examples in which these three key components are integrated for sensitive isolation and/or electrochemical detection of exosomes. The conclusion provides a summary of these initial achievements and also an outlook for future discoveries in exosome aptasensing using advanced nanomaterials, i.e., MXenes. MXenes have a promising outlook for affinity-based biosensing, being hydrophilic and rich in surface functional groups. In addition, the free plasmons present in MXenes can be used for covalent grafting of biorecognition elements using diazonium moieties. This is an especially interesting approach for the immobilization of DNA/RNA aptamers, which can be readily modified by diazonium moieties.