Translocation of Specific DNA Nanocarrier through an Ultrasmall Nanopipette: Toward Single-Protein-Molecule Detection with Superior Signal-to-Noise Ratio

Abstract

The use of functional DNA nanostructures as carriers to ship proteins through solid-state nanopores has recently seen substantial growth in single-protein-molecule detection (SPMD), driven by the potential of this methodology and implementations that it may enable. Ultrasmall nanopores have exhibited obvious advantages in spatiotemporal biological detection due to the appropriate nanoconfined spaces and unique properties. Herein, a 6.8 nm DNA tetrahedron (TDN) with a target-specific DNA aptamer (TDN-apt) was engineered to carry the representative target of acetylcholinesterase (AChE) through an ultrasmall nanopipet with a 30 nm orifice, underpinning the advanced SPMD of AChE with good performance in terms of high selectivity, low detection limit (0.1 fM), and especially superior signal-to-noise ratio (SNR). The kinetic interaction between TDN-apt and AChE was studied and the practical applicability of the as-developed SPMD toward real samples was validated using serum samples from patients with Alzheimer’s disease. This work not only presented a feasible SPMD solution toward low-abundance proteins in complex samples and but also was envisioned to inspire more interest in the design and implementation of synergized DNA nanostructure–ultrasmall nanopore systems for future SPMD development.

The Modification and Applications of Nanopipettes in Electrochemical Analysis

“…Due to the stable reference potential, Ag/AgCl is usually used as the working and reference electrodes. [16] The [17] with the permission of American Chemical Society. (b) self-referenced nanopipette for electrochemical analysis of hydrogen peroxide in the nucleus of a single living cell.…”

“…Xu et al developed a synergized DNA nanostructure-ultrasmall nanopore system using the single-nanopipette for the singleprotein-molecule detection with a superior signal-to-noise ratio. [17] Recently, a self-referenced nanopipette was reported for electrochemical analysis of hydrogen peroxide in the nucleus of a single living cell. [18] The self-referenced nanopipette was assembled by incorporating a reference electrode inside the nanopipette, with a Pt layer at the tip, which solved the problem that the single-nanopipette might interrupt the cellular activity (Figure 1b).…”

“…(a) single nanopipette for the single-protein-molecule detection with a superior signal-to-noise ratio. Reproduced from Ref [17]. with the permission of American Chemical Society.…”

Constraints on Knot Insertion, Not Internal Jamming, Control Polycatenane Translocation Dynamics through Crystalline Pores

“…The translocation of polymers through pores is ubiquitous in biology, and it is driving new advances in contemporary nano- and biotechnology. − In biological settings, translocation processes include the passage of mRNA and DNA through pore complexes and the transport of proteins through membrane channels, including during viral infection . Polymer translocation also has broad practical applications in biotechnology, spanning polymer characterization and separation, , gene therapy, DNA sequencing, , and controlled drug delivery .…”

Alkaline Phosphatase-Mediated Bioetching of CoOOH/BiVO4 for Signal-On Organic Photoelectrochemical Transistor Bioanalysis

“…For example, Liu et al introduced energy transfer-based PEC sensors for in vivo monitoring neurochemicals in the brain; Fu and Zhang reported a synergistic resonance-mediated PEC system to real time recognize tumor cells in the mouse tail; and Dai et al constructed a switchable dual-modal colorimetric and PEC biosensing platform for DNA analysis . More recently, we engineered nanopipettes − into nanoscale PEC electrodes , toward intracellular probing down to single-cell levels. However, one major problem was still concentrated on its intrinsic inability to amplify signals.…”