Premium
Label‐Free Pyrophosphate Recognition with Functionalized Asymmetric Nanopores
Author(s) -
Ali Mubarak,
Ahmed Ishtiaq,
Ramirez Patricio,
Nasir Saima,
Niemeyer Christof M.,
Mafe Salvador,
Ensinger Wolfgang
Publication year - 2016
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201600160
Subject(s) - pyrophosphate , nanopore , molecular recognition , nanotechnology , materials science , chemistry , biochemistry , organic chemistry , molecule , enzyme
The label‐free detection of pyrophosphate (PPi) anions with a nanofluidic sensing device based on asymmetric nanopores is demonstrated. The pore surface is functionalized with zinc complexes based on two di(2‐picolyl)amine [bis(DPA)] moieties using carbodiimide coupling chemistry. The complexation of zinc (Zn 2+ ) ion is achieved by exposing the modified pore to a solution of zinc chloride to form bis(Zn 2+ –DPA) complexes. The chemical functionalization is demonstrated by recording the changes in the observed current–voltage ( I–V ) curves before and after pore modification. The bis(Zn 2+ –DPA) complexes on the pore walls serve as recognition sites for pyrophosphate anion. The experimental results show that the proposed nanofluidic sensor has the ability to sense picomolar concentrations of PPi anion in the surrounding environment. On the contrary, it does not respond to other phosphate anions, including monohydrogen phosphate, dihydrogen phosphate, adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate. The experimental results are described theoretically by using a model based on the Poisson–Nernst–Planck equations.