Aptamer-Modified Magnetic Beads in Biosensing

Abstract

Magnetic beads (MBs) are versatile tools for the purification, detection, and quantitative analysis of analytes from complex matrices. The superparamagnetic property of magnetic beads qualifies them for various analytical applications. To provide specificity, MBs can be decorated with ligands like aptamers, antibodies and peptides. In this context, aptamers are emerging as particular promising ligands due to a number of advantages. Most importantly, the chemical synthesis of aptamers enables straightforward and controlled chemical modification with linker molecules and dyes. Moreover, aptamers facilitate novel sensing strategies based on their oligonucleotide nature that cannot be realized with conventional peptide-based ligands. Due to these benefits, the combination of aptamers and MBs was already used in various analytical applications which are summarized in this article.

A Guideline for Effectively Synthesizing and Characterizing Magnetic Nanoparticles for Advancing Nanobiotechnology: A Review

“…Magnetic nanoparticles have broadly used in diverse nanosensors, especially biosensors [189]. The surface functionalization of the magnetic nanoparticles, such as aptamer-modified magnetic nanoparticles, is a critical key in biosensing as it not only enhances their biocompatibility but also their specificity [190]. The magnetic interaction between the magnetic nanoparticles is the basis of their application in biosensors granted to their large surface to volume ratio leading to very high binding affinity [191].…”

Application of high-performance magnetic nanobeads to biological sensing devices

“…For these applications, magnetic materials should be subjected to coating and conjugation with appropriate materials on the surfaces of particles [ 5 , 6 ]. With use of functionalized magnetic particles, a broad range of biosensing systems (e.g., immunoassays) for bioimaging or drug delivery have been developed [ 7 – 9 ]. Several types of magnetic particles have been developed for various biotechnological applications [ 10 , 11 ].…”

Development of Aptamer-Based TID Assays Using Thermophoresis and Microarrays

“…Since most aptamers undergo structural changes upon target-binding, their target-induced conformational reorganization can be utilized for detection strategies, e.g., in aptamer-microarrays [31] or other biosensing platforms [21]. The nucleic acid-based sequence of aptamers allows for the design of oligonucleotides which are complementary to the target-binding site of the aptamer and can compete with the target in various assays [31,32]. The target-induced dissociation (TID) of complementary oligonucleotides allows for the detection of targets without labeling the analyte [32].…”