Transcript Diapositive 1

SensorART
BioMEMs Specifications and Development: Biosensors for early
detection of VAD-related complications
INTRODUCTION
SensorART aims to provide a set of technologies for heart assistance, supporting patients with
chronic heart failure, treated at home without renouncing to access high medical expertise, and
healthcare professionals, keeping under control the performance of cardiovascular implanted
Ventricular Assist Devices (VAD) by tele-control services.
Recent advances in cardiac surgery have decreased cardiac morality, but a high number of
postoperative deaths can be attributed to inappropriate myocardial protective techniques
applied during the operative phase of extracorporeal circulation or to the a cytokine storm that
is a potentially fatal immune reaction consisting of a positive feedback loop between cytokines
and immune cells, with highly elevated levels of various cytokines. Therefore, the development
of a rapid procedure for assessing concentrations of inflammatory biomarkers would be a
valuable tool for diagnosis and therapy evaluation in comparison to ELISA-based techniques.
One of the new approaches in the SensorART project was to improve the response by
impedancemetric measurements, whereby the immobilization of the specific antibodies on gold
microelectrodes were analyzed against different types of antigens associated with both pro &
anti-inflammatory biomarkers (Tumor Necrosis Factor-α, Interleukin-1α, Interleukin-6,
Interleukin 10, and Interleukin 1 receptor antagonist).
Biosensor Production on Polyimide
Fabrication of Silicon Master Molds
(a)
(b)
(c)
(d)
Silicon molds were developed by standard micro-optical lithography masks for the
fabrication of the (a) microelectrodes and (b) microfluidic system. Eight working
electrodes (WE’s) were developed for multiplex detection. This included a counter
electrode (CE) and two reference electrodes (RE’s). (c) The alignment of the
microelectrodes and microfluidic body. (d) The final concept for microelectrodes on
polyimide (PI) and the microfluidic system in polydimethylsiloxane (PDMS).
Biorecognition and Lab-on-Chip
Electrochemical Impedance Spectroscopy (EIS) for the Detection of Cytokines
(ai)
(a) Schematic biorecognition on the gold WE, (b) IL-10 detection on
the WE’s, (c) modified diazonium-mAb’s on the gold WE’s with an
integrated Ag/AgCl RE’s, and (d) TNF-α detection with nonfluorescence attributable to the negative test.
The fabrication of gold microelectrode on PI: (a) casting of PDMS
on the silicon mold, (b, c) peeling of the PDMS stamp from the
silicon mold with microelectrode geometry, (d) inking the PDMS
stamp with octadecylthiol (ODT), (e) microcontact printing (µCP)
of the inked stamp with the gold substrate, (f) self-assembled
monolayer (SAMs) formation onto the gold layer, (g) wet etching
of gold not protected with SAMs, and (h) optical image of the chip
based on a PI substrate.
(aii)
(bi)
(bii)
(ci)
(cii)
Nyquist plot of EIS on modified gold microelectrodes for human cytokine detection
ranging from 1 pg/mL to 15 pg/mL with: (Top) (a) IL-6, (b) IL-1β, and (c) IL-10, and
(Bottom) Normalization of the curves with interferences attributable to non-specific
binding of inactive proteins.
PDMS microfluidic system
chemically bonded to the PI
substrate.
The completed
SensorART Lab-on-aChip.
GENERAL INFORMATION
The UCBL Team
Starting date: 01/03/2010
Duration in months: 48
Call (part) identifier: FP7-ICT-2009-4
Budget: 8,500.000.00 €
Coordinator: IFC-CNR
Prof. Abdelhamid Errachid:
[email protected]
Dr Nicole Jafreeiz-Renault, Dr Nadia Zine,
Dr Carole Chaix-Bauvais, Dr Monique
Siguad, Dr Abdellatif Baraket, Dr Michael
Lee, and Alvaro Gracia-Cruz
ELISA versus EIS measurements for LVAD patient plasma IL-10 cytokine levels