A comparative study of in-flow and micro-patterning biofunctionalization protocols for nanophotonic silicon-based biosensors
González-Guerrero, Ana Belén (Institut Català de Nanociència i Nanotecnologia)
Alvarez, Mar (Institut Català de Nanociència i Nanotecnologia)
García Castaño, Andrés (Institut de Microelectrònica de Barcelona)
Dominguez, Carlos (Institut de Microelectrònica de Barcelona)
Lechuga, Laura M (Institut Català de Nanociència i Nanotecnologia)

Data:	2013
Resum:	Reliable immobilization of bioreceptors over any sensor surface is the most crucial step for achieving high performance, selective and sensitive biosensor devices able to analyze human samples without the need of previous processing. With this aim, we have implemented an optimized scheme to covalently biofunctionalize the sensor area of a novel nanophotonic interferometric biosensor. The proposed method is based on the ex-situ silanization of the silicon nitride transducer surface by the use of a carboxyl water soluble silane, the carboxyethylsilanetriol sodium salt (CTES). The use of an organosilane stable in water entails advantages in comparison with usual trialkoxysilanes such as avoiding the generation of organic waste and leading to the assembly of compact monolayers due to the high dielectric constant of water. Additionally, cross-linking is prevented when the conditions (e. g. immersion time, concentration of silane) are optimized. This covalent strategy is followed by the bioreceptor linkage on the sensor area surface using two different approaches: an in-flow patterning and a microcontact printing using a biodeposition system. The performance of the different bioreceptor layers assembled is compared by the real-time and label-free immunosensing of the proteins BSA/mAb BSA, employed as a model molecular pair. Although the results demonstrated that both strategies provide the biosensor with a stable biological interface, the performance of the bioreceptor layer assembled by microcontact printing slightly improves the biosensing capabilities of the photonic biosensor. © 2012 Elsevier Inc.
Nota:	Authors acknowledge financial support from M. Botín foundation. The authors also would like to acknowledge Dr. Daniel Ruiz Molina and Pablo González from Nanostructured Functional Materials Group, CIN2 (Barcelona), for assistance in AFM experiments and data analysis.
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Matèria:	Aqueous-silane ; Biofunctionalization ; CTES ; Micro-patterning ; Photonic biosensors ; Silicon interferometers
Publicat a:	Journal of colloid and interface science, Vol. 393 (March 2013) , p. 402-410, ISSN 1095-7103

DOI: 10.1016/j.jcis.2012.10.040

Postprint 21 p, 1.1 MB

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