Detection of catechol using mixed Langmuir-Blodgett films of a phospholipid and phthalocyanines as voltammetric sensors

The combination of metallic phthalocyanines (MPcs) and biomolecules has been explored in the literature either as mimetic systems to investigate molecular interactions or as supporting layers to immobilize biomolecules. Here, Langmuir-Blodgett (LB) films containing the phospholipid dimyristoyl phosp...

Full description

Saved in:
Bibliographic Details
Published in:Analyst (London) 2010-01, Vol.135 (1), p.2591-2599
Main Authors: Alessio, Priscila, Pavinatto, Felippe J, Oliveira Jr, Osvaldo N, De Saja Saez, Jose Antonio, Constantino, Carlos J. L, Rodríguez-Méndez, Maria Luz
Format: Article
Language:English
Subjects:
Analytical chemistry
Biomolecules
Catechol
Catechols - analysis
Chemistry
Electrochemical methods
Electrochemical Techniques - methods
Electrodes
Exact sciences and technology
Ferrous Compounds - chemistry
General, instrumentation
Glycerophospholipids - chemistry
Indium tin oxide
Indoles - chemistry
Kinetics
Langmuir-Blodgett films
Phospholipids
Sensors
Spectrometric and optical methods
Spectroscopy, Fourier Transform Infrared
Stability
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The combination of metallic phthalocyanines (MPcs) and biomolecules has been explored in the literature either as mimetic systems to investigate molecular interactions or as supporting layers to immobilize biomolecules. Here, Langmuir-Blodgett (LB) films containing the phospholipid dimyristoyl phosphatidic acid (DMPA) mixed either with iron phthalocyanine (FePc) or with lutetium bisphthalocyanine (LuPc 2 ) were applied as ITO modified-electrodes in the detection of catechol using cyclic voltammetry. The mixed Langmuir films of FePc + DMPA and LuPc 2 + DMPA displayed surface-pressure isotherms with no evidence of molecular-level interactions. The Fourier Transform Infrared (FTIR) spectra of the multilayer LB films confirmed the lack of interaction between the components. The DMPA and the FePc molecules were found to be oriented perpendicularly to the substrate, while LuPc 2 molecules were randomly organized. The phospholipid matrix induced a remarkable electrocatalytic effect on the phthalocyanines; as a result the mixed LB films deposited on ITO could be used to detect catechol with detection limits of 4.30 × 10 −7 and 3.34 × 10 −7 M for FePc + DMPA and LuPc 2 + DMPA, respectively. Results from kinetics experiments revealed that ion diffusion dominated the response of the modified electrodes. The sensitivity was comparable to that of other non-enzymatic sensors, which is sufficient to detect catechol in the food industry. The higher stability of the electrochemical response of the LB films and the ability to control the molecular architecture are promising for further studies with incorporation of biomolecules. Phospholipids and phthalocyanines processed as Langmuir-Blodgett films for modification of electrodes and voltammetric detection of catechol.
ISSN:0003-2654
1364-5528
DOI:10.1039/c0an00159g