Surface functionalization of germanium ATR devices for use in FTIR-biosensors

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:332

Article

Devouge, Sabrina¹  Conti, Josephine²  Goldsztein, Andrea³  Gosselin, Emmanuel²  Brans, Alain⁴  Voue, Michel²  De Coninck, Joel²  Homble, Fabrice³  Goormaghtigh, Erik³  Marchand-Brynaert, Jacqueline¹ 

[1] Catholic Univ Louvain, Unite Chim Organ & Med, B-1348 Louvain, Belgium

[2] Univ Mons Hainaut, Ctr Rech & Modelisat Mol, B-7000 Mons, Belgium

[3] Univ Libre Bruxelles, Lab Struct & Fonct Membranes Biol, Ctr Biol Struct & Bioinformat, B-1050 Brussels, Belgium

[4] Univ Liege, Ctr Ingn Prot, B-4000 Sart Tilman Par Liege, Belgium

关键词: Germanium;    ATR crystal;    FTIR biosensors;    Thin film;    Phenyl azide;    Photografting;    BlaR-CTD protein;    Non-fouling surface;   

DOI  :  10.1016/j.jcis.2008.12.045

来源: Elsevier

【 摘 要 】

Biosensors based on intrinsic detection methods have attracted growing interest. The use of Fourier transform infra-red (FTIR) spectroscopy with the attenuated internal total reflection (ATR) mode, in the biodetection context, requires appropriate surface functionalization of the ATR optical element. Here, we report the direct grafting of a thin organic layer (about 20 angstrom depth) on the surface of a germanium crystal. This covering, constructed with novel amphiphilic molecules 2b (namely, 2,5,8,11,14,17,20-heptaoxadocosan-22-yl-3-(triethoxysilyl) propylcarbamate), is stable for several hours under phosphate buffered saline (PBS) flux and features protein-repulsive properties. Photografting of molecule 5 (namely, O-succinimidyl 4-(p-azidophenyl)butanoate) affords the activated ATR element, ready for the covalent fixation of receptors, penicillin recognizing proteins BlaR-CrD for instance. The different steps of the previous construction have been monitored by water contact angle (theta(w)) measurements, spectroscopic ellipsometry (covering depth), X-ray photoelectron spectroscopy (XPS) by using a fluorinated tag for the control of surface reactivity, and FTIR-ATR spectroscopy for the structural analysis of grafted molecules. Indeed, contrarily to silicon device, germanium device offers a broad spectral window (1000-4000 cm(-1)) and thus amide I and II absorption bands can be recorded. This work lays the foundations for the construction of novel FTIR biosensors. (c) 2008 Elsevier Inc. All rights reserved.

【 授权许可】

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