Solid‐state Nanopores: Chemical Modifications, Interactions, and Functionalities

Abstract

Nanopore technology is a burgeoning detection technology for single-molecular sensing and ion rectification. Solid-state nanopores have attracted more and more attention because of their higher stability and tunability than biological nanopores. However, solid-state nanopores still suffer the drawbacks of low signal-to-noise ratio and low resolution, which hinder their practical applications. Thus, developing operatical and useful methods to overcome the shortages of solid-state nanopores is urgently needed. Here, we summarize the recent research on nanopore modification to achieve this goal. Modifying solid-state nanopores with different coating molecules can improve the selectivity, sensitivity, and stability of nanopores. The modified molecules can introduce different functions into the nanopores, greatly expanding the applications of this novel detection technology. We hope that this review of nanopore modification will provide new ideas for this field.

Mapping the Acetylamino and Carboxyl Groups on Glycans by Engineered α-Hemolysin Nanopores

“…25−27 However, due to its low signal-to-noise ratio and low resolution, the solid-state nanopores cannot fully discriminate between individual monosaccharides or polysaccharides. 28 Three biological nanopore, Mycobacterium smegmatis porin A (MspA), aerolysin (AeL), and α-hemolysin (α-HL) nanopore permit the detection of glycans. 29−33 Phenylboronic acid-appended hetero-octameric MspA nanopore has recently been exploited for the detection of nine types of monosaccharides and the identification of polyol sweeteners.…”

“…Few studies have been reported on the nanopore detection of glycans, suggesting that nanopores have great potential to manage this task. For example, solid-state nanopores have been applied to detect the glycosaminoglycans, polysaccharides, and glycoproteins. − However, due to its low signal-to-noise ratio and low resolution, the solid-state nanopores cannot fully discriminate between individual monosaccharides or polysaccharides . Three biological nanopore, Mycobacterium smegmatis porin A (MspA), aerolysin (AeL), and α-hemolysin (α-HL) nanopore permit the detection of glycans. − Phenylboronic acid-appended hetero-octameric MspA nanopore has recently been exploited for the detection of nine types of monosaccharides and the identification of polyol sweeteners. , Engineered α-HL has been used to detect isomers of d -glucose, d -fructose, or cyclodextrins. − To the best of our knowledge, mapping the functional groups of glycans and identifying oligosaccharides via functional group patterns using nanopores have not been reported.…”

Functional Nanopores Enabled with DNA

“…The passage of small analytes through the large lumen of a solid‐state nanopore can occur too rapidly to yield measurable signals. To overcome this issue, molecular modifications [75] and nanobeads [76] have been incorporated in the pores to slow translocation. A further limitation of solid‐state nanopores is associated with the wide lumen and inconsistent lumen geometry which hinders the generation of reproducible signals.…”

Solid-State Nanopore Sensors with Enhanced Sensitivity through Nucleic Acid Amplification

“…The ion current rectification ratio has been widely used as a signal output for the qualitative and quantitative detection of various analytes. Despite many attempts to reduce noise and improve resolution, solid-state nanopore sensors still have lower sensitivity and poorer selectivity than biological nanopore sensors …”