Influence of Adsorption on Proteins and Amyloid Detection by Silicon Nitride Nanopore

Abstract

For the past 2 decades, emerging single-nanopore technologies have opened the route to multiple sensing applications. Besides DNA sensing, the identification of proteins and amyloids is a promising field for early diagnosis. However, the influence of the interactions between the nanopore surface and proteins should be taken into account. In this work, we have selected three proteins (avidin, lysozyme, and IgG) that exhibit different affinities with the SiNx surface, and we have also examined lysozyme amyloid. Our results show that the piranha treatment of SiNx significantly decreases protein adsorption. Moreover, we have successfully detected all proteins (pore diameter 17 nm) and shown the possibility of discriminating between denatured lysozyme and its amyloid. For all proteins, the capture rates are lower than expected, and we evidence that they are correlated with the affinity of proteins to the surface. Our result confirms that proteins interacting only with the nanopore surface wall stay long enough to be detected. For lysozyme amyloid, we show that the use of the nanopore is suitable for determining the number of monomer units even if only the proteins interacting with the nanopore are detected.

Identification of single amino acid differences in uniformly charged homopolymeric peptides with aerolysin nanopore

“…Pioneering studies were devoted to the dynamics of peptides transport 9 , 10 , 13 , 14 , 16 , 30 , and then to the dynamics of unfolded proteins transport 18 , 31 , 48 through the nanopore. Others studies focused on protein-antibodies complex 32 , 41 , 42 , on intrinsically disordered proteins 49 , on enzymatic reactions 15 , 17 , 23 , 60 , 61 and on the aggregation of amyloidogenic peptides 36 , 47 , 55 . The unfolding of proteins was investigated, either in the presence of an unfolding agent 12 , 31 , 44 , or by varying temperature 24 , or with an electrical force 50 , 62 , or with a molecular motor such as an unfoldase 27 .…”

Single molecule sensing of amyloid-β aggregation by confined glass nanopores

“…Benetting from the advantages of single molecule characterization, nanopore-based analytics has been employed for the sensing of individual amyloid particles 22 such as a synuclein, 23,24 lysozyme, 25,26 amyloid b, [27][28][29] etc. For example, solid state nanopores were used to enable the translocation of amyloid b aggregates and further measure the size of individual oligomers in solution without chemical modication.…”

“…3e). The adsorption of protein aggregates onto the nanopore has been investigated 25 and great effort has been made to prevent nonspecic adsorption. 26,[29][30][31] Herein, only the Ab1-42 oligomers showed an obvious adsorption, which could be conrmed by the increase in the ion current rectication ratio.…”

Microfluidic and Nanofluidic Resistive Pulse Sensing: A Review

“…The silicon-based nanopore is another popular nanopore which can be fabricated by using the electron beam writing method [ 124 , 125 , 126 ]. The diameter of such a nanopore can be smaller than 10 nm [ 125 ].…”