Effects of valinomycin doping on the electrical and structural properties of planar lipid bilayers supported on polyelectrolyte multilayers

EDUART GUTIÉRREZ PINEDA; PATRIZIA ANDREOZZI; ELEFTHERIA DIAMANTI; RAMIRO ANGUIANO; RONALD.F. ZIOLO; SERGIO E. MOYA; MARÍA JOSÉ RODRÍGUEZ PRESA; CLAUDIO A. GERVASI

BIOELECTROCHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2021 vol. 138

1567-5394

Supported Lipid Bilayers (SLBs) on Polyelectrolyte Multilayers (PEMs) have large potential as models fordeveloping sensor devices. SLBs can be designed with receptors and channels, which benefit from the biologicalenvironment of the lipid layers, to create a sensing interface for ions and biomarkers. PEMs assembledby the Layer-by-Layer (LBL) technique and used as supports for a lipid bilayer enable an easyintegration of the bilayer on almost any surface and device. For electrochemical sensors, LBL assemblyenables nanoscale tunable separation of the lipid bilayer from the electrode surface, avoiding undesiredeffects of the electrode surface on the lipid bilayers. We study the fabrication of valinomycin-doped SLBson PEMs as a model system for biophysical studies and for selective ion sensing. SLBs are fabricated fromdioleoylphosphatidylcholine (DOPC) and dioleoylphosphatidylserine (DOPS) 50:50 vesicles doped withvalinomycin, as a K+-selective carrier. SLBs were deposited on electrodes coated with poly(allyl aminehydrochloride) (PAH) and poly(styrene sodium sulfonate) (PSS) multilayers. Lipid bilayer formationwas monitored by using Quartz Crystal Microbalance with Dissipation (QCMD) technique and AtomicForce Microscopy (AFM). Electrochemical impedance spectroscopy (EIS) and potentiometric measurementswere performed to assess K+ selectivity over other ions and the potential of valinomycin-dopedSLBs for K+-sensing.