Self-standing, conducting and capacitive biomimetic hybrid nanomembranes for selective molecular ion separation

Phys Chem Chem Phys. 2021 Aug 4;23(30):16157-16164. doi: 10.1039/d1cp01840j.

Abstract

Hybrid free-standing biomimetic materials are developed by integrating the VDAC36 β-barrel protein into robust and flexible three-layered polymer nanomembranes. The first and third layers are prepared by spin-coating a mixture of poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA). PVA nanofeatures are transformed into controlled nanoperforations by solvent-etching. The two nanoperforated PLA layers are separated by an electroactive layer, which is successfully electropolymerized by introducing a conducting sacrificial substrate under the first PLA nanosheet. Finally, the nanomaterial is consolidated by immobilizing the VDAC36 protein, active as an ion channel, into the nanoperforations of the upper layer. The integration of the protein causes a significant reduction of the material resistance, which decreases from 21.9 to 3.9 kΩ cm2. Electrochemical impedance spectroscopy studies using inorganic ions and molecular metabolites (i.e.l-lysine and ATP) not only reveal that the hybrid films behave as electrochemical supercapacitors but also indicate the most appropriate conditions to obtain selective responses against molecular ions as a function of their charge. The combination of polymers and proteins is promising for the development of new devices for engineering, biotechnological and biomedical applications.

MeSH terms

  • Adenosine Triphosphate / chemistry
  • Biomimetic Materials / chemistry*
  • Bridged Bicyclo Compounds, Heterocyclic / chemistry*
  • Dielectric Spectroscopy
  • Electric Conductivity
  • Ion Channels / chemistry
  • Ion Transport
  • Ions / isolation & purification
  • Lysine / chemistry
  • Nanostructures / chemistry*
  • Polyesters / chemistry*
  • Polymers / chemistry*
  • Polystyrenes / chemistry*
  • Polyvinyl Alcohol / chemistry*
  • Structure-Activity Relationship
  • Surface Properties
  • Voltage-Dependent Anion Channels / chemistry*

Substances

  • Bridged Bicyclo Compounds, Heterocyclic
  • Ion Channels
  • Ions
  • Polyesters
  • Polymers
  • Polystyrenes
  • Voltage-Dependent Anion Channels
  • poly(3,4-ethylene dioxythiophene)
  • poly(lactide)
  • polystyrene sulfonic acid
  • Adenosine Triphosphate
  • Polyvinyl Alcohol
  • Lysine