Analyte‐Triggered DNA‐Probe Release from a Triplex Molecular Beacon for Nanopore Sensing

Abstract

A new nanopore sensing strategy based on triplex molecular beacon was developed for the detection of specific DNA or multivalent proteins. The sensor is composed of a triplex-forming molecular beacon and a stem-forming DNA component that is modified with a host-guest complex. Upon target DNA hybridizing with the molecular beacon loop or multivalent proteins binding to the recognition elements on the stem, the DNA probe is released and produces highly characteristic current signals when translocated through α-hemolysin. The frequency of current signatures can be used to quantify the concentrations of the target molecules. This sensing approach provides a simple, quick, and modular tool for the detection of specific macromolecules with high sensitivity and excellent selectivity. It may find useful applications in point-of-care diagnostics with a portable nanopore kit in the future.

Aerolysin, a Powerful Protein Sensor for Fundamental Studies and Development of Upcoming Applications

“…Only a few studies have been published on the detection of biomarkers model using protein nanopores. Most of those studies indirectly detect biomarkers by DNA assisted sensing [126][127][128] . To our knowledge, there are only a few articles on direct detection of biomarkers from serum for normal biological process 107,129 and human disease 34 .…”

Cucurbiturils in nucleic acids research

“…Since 2015, H.-C. Wu and co-workers are developing a versatile method for nanopore sensing of biologically related analytes based on DNA-CB [7] host-guest probes. [75][76][77][78][79][80][81][82][83] In the method developed by H.-C. Wu and co-workers, introduction of the analyte leads to the release or in situ formation of the single-stranded DNA (ssDNA) bearing a ferrocene-CB [7] or adamantane-CB [7] complex, referred to as a DNA probe. Threading of the DNA probe through the a-hemolysin (aHL) nanopore results in the dissociation of the host-guest complex and liberation of CB [7] (Fig.…”

“…Subsequent trapping and oscillation of free CB [7] in the vestibule of aHL produces a unique pattern of the current signature events that endows the detection with very high confidence at the single molecule level. The application of this strategy allowed to detect a large range of analytes of different size and nature, such as vascular endothelial growth factor (VEGF), thrombin, cocaine, 75 ssDNA, mono-/multivalent antibodies, 76 microRNA, 77 and cancer biomarkers, 78,79 with high levels of sensitivity. Selective epigenetic modification of 5-methylcytosine, 5-hydroxymethylcytosine 80 and 8-oxo-2 0 -deoxyguanosine 81 by attachment of the ferrocene-CB[7] 80 or adamantane-CB [7] 81 complexes allowed to apply the CB-based aHL nanopore sensing to detect the presence of these nucleobases in single-stranded DNA oligonucleotides.…”

Enzyme and AIEgens Modulated Solid‐State Nanochannels: In Situ and Noninvasive Monitoring of H2O2 Released from Living Cells

“…When functional molecules are modified into nanochannels, targets bond with these functional molecules and form covalent or noncovalent interactions specifically. These interactions between functional molecules and targets will alter the properties of nanochannel surface, which change ionic transmission and thus affect ionic current . Generally speaking, the analysis principle based on solid‐state nanochannels can be summarized as follows: 1) targets go across the solid‐state nanochannels or react with inner surface of the solid‐state nanochannels, adjust the effective radius of the nanochannels; 2) influence the surface charge density along with 3) the wettability of the confined space of the nanochannels, resulting in transmembrane ionic current change which can be monitored …”