Selective functionalisation of PDMS-based photonic lab on a chip for biosensing


AU: 
Ibarlucea, B; Fernández-Sánchez, C; Demming, S; Büttgenbachb, S; Llobera, A
SO: 
Analyst
Autors del GTQ: 
IS: 
17
BP: 
3496
EP: 
3502
PY: 
2011
SN: 
0003-2654
Impact: 
3.91
Any IF: 
2010
Resum: 

A comparative study of different approaches for the selective immobilisation of biomolecules on the surface of poly(dimethylsiloxane) (PDMS) is reported. The motivation of this work is to set a robust and reliable protocol for the easy implementation of a biosensor device in a PDMS-based photonic labon- a-chip (PhLoC). A hollow prism configuration, previously reported for the colorimetric detection of analytes was chosen for this study. Here, the inner walls of the hollow prism were initially modified by direct adsorption of either polyethylene glycol (PEG) or polyvinyl alcohol (PVA) linear polymers as well as by carrying out a light chemical oxidation step. All these processes introduced hydroxyl groups on the PDMS surface to a different extent. The hydroxyl groups were further silanised using a silane containing an aldehyde end-group. The interaction between this group and a primary amine moiety enabled the selective covalent attachment of a biomolecule on the PDMS surface. A thorough structural characterisation of the resulting modified-PDMS substrates was carried out by contact angle measurements, X-ray photoelectron spectroscopic (XPS) analysis and atomic force microscopy (AFM) imaging. Using horseradish peroxidase as a model recognition element, different biosensor approaches based on each modification process were developed for the detection of hydrogen peroxide target analyte in a concentration range from 0.1 mMto 100 mM. The analytical performance was similar in all cases, a linear concentration range between 0.1 mM and 24.2 mM, a sensitivity of 0.02 a.u. mM_1 and a limit of detection around 0.1 mMwere achieved. However, important differences were observed in the reproducibility of the devices as well as in their operational stability, which was studied over a period of up to two months. Considering all these studies, the PVA-modified approach appeared to be the most suitable one for the simple fabrication of a biosensor device integrated in a PDMS PhLoC.

DT: 
Article en revistes indexades
Percentil: 
HIGH
Any Percentil: 
2010
Categoria: 
CHEMISTRY, ANALYTICAL