Two Detection Modes of Nanoslit Sensing Based on Planar Heterostructure of Graphene/Hexagonal Boron Nitride

Abstract

Solid-state nanopore sequencing is now confronted with problems of stochastic pore clogging and too fast speed during the DNA permeation through a nanopore, although this technique is revolutionary with long readability and high efficiency. These two problems are related to controlling molecular transportation during sequencing. To control the DNA motion and identify the four bases, we propose nanoslit sensing based on the planar heterostructure of two-dimensional graphene and hexagonal boron nitride. Molecular dynamics simulations are performed on investigating the motion of DNA molecules on the heterostructure with a nanoslit sensor. Results show that the DNA molecules are confined within the hexagonal boron nitride (HBN) domain of the heterostructure. And the confinement effects of the heterostructure can be optimized by tailoring the stripe length. Besides, there are two ways of DNA permeation through nanoslits: the DNA can cross or translocate the nanoslit under applied voltages along the y and z directions. The two detection modes are named cross-slit and trans-slit, respectively. In both modes, the ionic current drops can be observed when the nanoslit is occupied by the DNA. And the ionic currents and dwell times can be simultaneously detected to identify the four different DNA bases. This study can shed light on the sensing mechanism based on the nanoslit sensor of a planar heterostructure and provide theoretical guidance on designing devices controlling molecular transportation during nanopore sequencing.

Self-cleaning formulations of mixed metal oxide-silver micro-nano structures with spiky coronae as antimicrobial coatings for fabrics and surfaces

“…11 Recently, Lulu Huang et al have designed DNA-modified spiky gold nanoparticles and visualized the influence of spikes on myosin IIA recruitment at the cell membrane, improving the cellular uptake effectiveness. 12 From the above-mentioned studies reported in the literature, it is clear that spiky structures will interact better with the biological membrane than the spherical particles.…”

Aggregation-Enabled Electrochemistry in Confined Nanopore Capable of Complementary Faradaic and Non-Faradaic Detection

“…Dual-mode detection, integrating two independent signals from distinct rationales, permits cross-checking of mutually corroborated signals and thus delivers more reliable results. , Iontronic bioanalysis represents a nanoscopic detection technique based on directional ionic migration and analyte-dependent modulation of the ionic signals without Ohmic contacts. − By rational engineering of nanopipettes, this technique has attracted increasing attention in probing intracellular species. , For example, by nanopore confinement of PbS quantum dots within a polymeric matrix, light-induced ionic currents were utilized for cytoplasmic O 2 detection . On the other hand, photoelectrochemical (PEC) bioanalysis represents a rapidly developing bioanalytical technique using noncontact light as an excitation source, which eliminates the imposed voltage and enables zero-bias operation. − By downscaling the photoelectrodes, our recent work has repurposed traditional PEC bioanalysis, from in vitro application in bulk solutions to nanoscopic single-cell detection. , For example, an organic dye with a NiO/Ni layer was constructed on a nanopipette for photocathodic assessment of single-cell oxidative stress .…”

The Role of MXene Surface Terminations on Peptide Transportation in Nanopore Sensing

“…It is reported that altering the cation of the electrolyte , and the combination of ionic liquid and aqueous electrolyte can control and effectively slow the DNA motion. Usually, decreasing the electrical field can also largely slow down the translocation of charged molecules due to the decreased electrophoretic force. − Regarding the nanopore size and geometry, studies have shown that the ionic profile caused by geometrical variation has a great influence on the dwell time of molecules. , In addition, the heterostructure is normally used to design the moving path of molecules, , and our previous work found that the heterostructure of graphene/hexagonal boron nitride can largely reduce translocation speeds of nucleotides …”

“…20,21 In addition, the heterostructure is normally used to design the moving path of molecules, 22,25 and our previous work found that the heterostructure of graphene/hexagonal boron nitride can largely reduce translocation speeds of nucleotides. 24 MXenes (Ti n+1 C n T x ), as two-dimensional materials, can be introduced with different surface terminations to modify their surface chemistry, and thus have large applications in nanopore sensing. 26−28 In experimental studies, MXene (Ti 3 C 2 T x ) with mixed surface terminations of −O, −OH, and −F showed good applicability in DNA identification 29,30 and gas sensing, 31 but the influence of surface terminations was ambiguous.…”

“…The translocation speeds can be affected by many factors, such as the electrolytes, − external applied fields, − nanopore size and geometry, , nanopore materials, − and so on. It is reported that altering the cation of the electrolyte , and the combination of ionic liquid and aqueous electrolyte can control and effectively slow the DNA motion.…”