Nanopore label‐free detection of single‐nucleotide deletion in Baxα/BaxΔ2

Abstract

Baxα, a key tumor suppressor gene, will not be expressed correctly as a result of single nucleotide mutation in its microsatellite region; Instead, BaxΔ2, an isoform of Baxα, is often produced. In addition, lack of the exon 2 due to an alternative splicing, BaxΔ2 has the same sequence as Baxα except single base deletion from eight continuous guanines (G8) to G7. Most of the currently available methods for Bax∆2 detection are inefficient and time-consuming, and/or require the use of labels or dyes. In this work, we reported a label-free nanopore sensing strategy to differentiate between Baxα and BaxΔ2 with a DNA polymer as a molecular probe based on alternative spliced sequences. Two DNA molecules were designed to selectively detect Baxα and BaxΔ2, respectively. The method was rapid, accurate, and highly sensitive: picomolar concentrations of target nucleic acids could be detected in minutes. Our developed simple and fast nanopore-based detection strategy is not only useful for distinguishing between Baxα and Bax∆2, but also provides a useful tool for detection of other single-base mutations in genetic diagnosis.

Salt-Mediated Nanopore Detection of ADAM-17

“…In addition to the salt effect, the applied voltage bias also significantly affected the performance of the nanopore sensor. 32 For this purpose, nanopore detection of ADAM-17 was further performed at +80 mV and +100 mV. As shown in Figure 3, with a decrease in the applied potential from +120 mV to +80 mV, the normalized event mean residual current for the substrate cleavage products was almost unchanged (from 48.6 ± 1.0% to 46.9 ± 0.5% of channel block), the residence time decreased by 17% (from 0.83 ± 0.02 ms to 0.71 ± 0.05 ms), while the frequency decreased by 115% (from 2.54 s −1 to 1.18 s −1 ).…”

“…In addition to the salt effect, the applied voltage bias also significantly affected the performance of the nanopore sensor . For this purpose, nanopore detection of ADAM-17 was further performed at +80 mV and +100 mV.…”

Ultrasensitive and Label-Free Detection of Copper Ions by GHK-Modified Asymmetric Nanochannels

“…Nanochannels have proven to be a sensitive and powerful tool in detecting metal ions ,, small molecules, , and biomacromolecules including DNA, RNA, , peptides, , proteins, and enzymes . The ion track-etched solid-state nanochannels have attracted increasing interest due to their unique capability of selective ionic transport based on the surface charge and conical shape .…”

Nanopore-Based Strategy for Sensing of Copper(II) Ion and Real-Time Monitoring of a Click Reaction

“…The use of nanopores is a powerful and sensitive tool for single-molecule analysis. − When a charged molecule interacts with or passes through a nanopore, the ionic current through the pore is modulated, and the resulting current changes can be recorded in real time to reveal the properties of the molecule in question . So far, nanopore sensors have been successfully employed to detect small molecules, − organic molecules, and even biomacromolecules such as DNA, − RNA, − peptides, , proteins, − and enzymes. , Since the pioneering work of Bayley et al on the simultaneous detection of divalent metal ions with an α-hemolysin (α-HL) mutant, several nanopore-based strategies have been developed for metal ion sensing, as exemplified by the use of T-Hg 2+ -T pairing, metal ion–chelator reactions, chelating probes, aptamer-modified nanomaterials combined with resistive pulse sensors, and a combination of translocation velocity with biphasic pulses . Recently, an aerolysin nanopore has been demonstrated to be extremely well suited for the discrimination of oligonucleotides with different lengths and the identification of four types of nucleotides and DNA methylation .…”