Nucleic acid hybridization on an electrically reconfigurable network of gold-coated magnetic nanoparticles enables microRNA detection in blood

Abstract

There is intense interest in quantifying the levels of microRNA because of its importance as a blood-borne biomarker. The challenge has been to develop methods that can monitor microRNA expression both over broad concentration ranges and in ultralow amounts directly in a patient's blood. Here, we show that, through electric-field-induced reconfiguration of a network of gold-coated magnetic nanoparticles modified by probe DNA (DNA-Au@MNPs), it is possible to create a highly sensitive sensor for direct analysis of nucleic acids in samples as complex as whole blood. The sensor is the first to be able to detect concentrations of microRNA from 10 aM to 1 nM in unprocessed blood samples. It can distinguish small variations in microRNA concentrations in blood samples of mice with growing tumours. The ultrasensitive and direct detection of microRNA using an electrically reconfigurable DNA-Au@MNPs network makes the reported device a promising tool for cancer diagnostics.

CRISPR/Cas13a‐Powered Electrochemical Microfluidic Biosensor for Nucleic Acid Amplification‐Free miRNA Diagnostics

“…Today, there are a few reports tackling these challenges, for example, by improving current detection methods, using electrochemical assays or developing pH‐based POC tests . However, these approaches still need error‐prone amplification steps prior to the miRNA detection, have rather tedious preparation steps, or are limited by the design of suitable primers .…”

High‐Performance Nucleic Acid Sensors for Liquid Biopsy Applications

“…DNAnanostructured-based electrochemical assays have been developed for miRNAa nalysis, [41] and graphenebased electrochemical methods are also compatible with this analyte. [43] [43] …”

Advances in Electrochemical (Bio)Sensing Targeting Epigenetic Modifications of Nucleic Acids

“…Reprinted from [54] (a) and [55] (b) with permission. Tavallaie et al [29] have proposed recently an attractive electrochemical sensor for the determination of miRNAs based on the use of an electrically reconfigurable DANN-gold-coated magnetic nanoparticles (Au@MNPs) network (DNA-Au@MNPs). In this method, Au@MNPs were modified with a thiolated and methylene blue (MB) dually labelled DNA probe complementary to the target miRNA (miRNA-21), incubated with the sample for hybridization with the target miRNA, and magnetically captured on the surface of a gold electrode (Figure 6a-c).…”

“…Accordingly, tremendous research (2), magnetic collection of the DNA-Au@MNPs on the surface of a gold microelectrode (3) and SWV signals obtained in the absence and in the presence of the target miRNA-21 (4). Reprinted and adapted from [29] with permission. efforts are being devoted to the development of methodologies that could bring a new era to the epigenetic research [13].…”