Improving the Performance of Selective Solid-State Nanopore Sensing Using a Polyhistidine-Tagged Monovalent...

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Biology

Background:

• Solid-state (SS-) nanopore sensing offers label-free detection but suffers from limited selectivity.
• Previous SS-nanopore assays used monovalent streptavidin (MS) for selective nucleic acid quantification.
• Enhanced sensitivity is crucial for detecting low-abundance molecular targets.

Purpose of the Study:

• To improve the sensitivity and selectivity of SS-nanopore assays for nucleic acid biomarker detection.
• To investigate the impact of incorporating a polyhistidine-tagged MS (hMS) on nanopore sensing performance.
• To expand the applicability of SS-nanopore technology for quantitative molecular analysis.

Main Methods:

• Developed a modified SS-nanopore assay utilizing a polyhistidine-tagged monovalent streptavidin (hMS).
• Investigated the influence of buffer pH, salt concentration, and SS-nanopore diameter on assay performance.
• Assessed the assay's sensitivity and selectivity using miRNA spiked into human plasma.

Main Results:

• Incorporating hMS significantly improved measurement sensitivity and selectivity compared to previous MS-based assays.
• The study identified optimal buffer and device parameters for enhanced nanopore sensing.
• Successfully detected as low as 1 nM miRNA in human plasma samples.

Conclusions:

• The hMS-modified SS-nanopore assay provides a substantial advancement in quantitative molecular biomarker analysis.
• This improved method broadens the potential applications of SS-nanopores in diagnostics and research.
• The findings pave the way for more sensitive and selective detection of low-abundance targets.