AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP35
Fabrication of a Polyallylamine-Based, Label-Free Piezoelectric Biosensor Platform

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: A. Papadopoulou-Bouraoui, European Commission-Joint Research Centre, Italy
Authors: A. Papadopoulou-Bouraoui, European Commission-Joint Research Centre, Italy
F. Bretagnol, European Commission-Joint Research Centre, Italy
M. Lejeune, European Commission-Joint Research Centre, Italy
A. Valsesia, European Commission-Joint Research Centre, Italy
J. Barrero-Moreno, European Commission-Joint Research Centre, Italy
D. Gilliland, European Commission-Joint Research Centre, Italy
G. Ceccone, European Commission-Joint Research Centre, Italy
F. Rossi, European Commission-Joint Research Centre, Italy
Correspondent: Click to Email
The Quartz-Crystal Microbalance (QCM) is a sensitive acoustic technique allowing the measurement of resonance frequency changes occurring due to changes in the total oscillating mass of the crystal. It operates as a highly sensitive weighing device. The aim of the present study was to use active amino groups provided through plasma deposition of an allylamine polymer film (PALL) towards further antibody immobilization. Two antibody immobilization routes were investigated. The first involved the use of glutaraldehyde as a crosslinker, followed by protein A (PA) or protein G (PG) for optimal antibody orientation and consecutively highly sensitive antibody-antigen interaction. The second involved the use nanometer-sized gold (20 nm) particles in combination with PA or PG. PALL films were deposited in a capacitively coupled plasma reactor onto the SiO2 covered surface of the quartz crystal and were completely characterized before antibody immobilisation. The active amino groups were quantified through evaluation of the X-Ray Photoelectron Spectroscopy (XPS) C1S high-resolution spectra of the trifluoromethylbenzaldehyde derivative. Evaluation of the stability and reactivity of all main intermediate steps was performed using the QCM in combination with other surface characterization techniques such as the Ellipsometry, Atomic Force Microscopy (AFM), Time-of-Flight Secondary Ion Mass Spectrometry and XPS. Results from this work show the possibility of producing simple, direct piezoelectric immunoprobes through appropriate antibody orientation, using PA or PG, or surface increase, using GNP, without the need for labeled compounds. The combination of surface analytical, optical and mass balance techniques is confirming the effectiveness of these immunosensor fabrication strategies. This fully characterized biosensor platform has been tested for the detection of a food allergen, ovalbumin.