Single Cigar-Shaped Nanopores Functionalized with Amphoteric Amino Acid Chains: Experimental and Theoretical Characterization

详细信息    查看全文

• 作者：Mubarak Ali ; Patricio Ramirez ; Hung Quoc Nguyen ; Saima Nasir ; Javier Cervera ; Salvador Mafe ; Wolfgang Ensinger
• 刊名：ACS Nano
• 出版年：2012
• 出版时间：April 24, 2012
• 年：2012
• 卷：6
• 期：4
• 页码：3631-3640
• 全文大小：645K
• 年卷期：v.6,no.4(April 24, 2012)
• ISSN：1936-086X

文摘

We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current鈥搗oltage (I鈥揤) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurable diode showing different rectifying behaviors by applying chemical and electrical signals. The remarkable characteristics of the new nanopore are the sharp response observed in the I鈥揤 curves, the improved tunability (with respect to previous designs of symmetric nanopores) which is achieved because of the direct external access to the nanostructure mouths, and the broad range of rectifying properties. The results concern both fundamental concepts useful for the understanding of transport processes in biological systems (ion channels) and applications relevant for tunable nanopore technology (information processing and drug controlled release).

Keywords:

cigar-shaped nanopore; amphoteric amino acid chains; current鈭抳oltage curves; logic functions