Microcantilever arrays functionalised with spiropyran photoactive moieties as systems to measure photo-induced surface stress changes

SENSORS AND ACTUATORS B-CHEMICAL

卷:237

Article

Grogan, Catherine^1,2  Florea, Larisa³  Koprivica, Slavica³  Scarmagnani, Silvia³  O'Neill, Luke²  Lyng, Fiona²  Pedreschi, Fran^1,2  Benito-Lopez, Fernando^3,4  Raiteri, Roberto⁵ 

[1] Dublin Inst Technol, Sch Phys, Kevin St, Dublin 8, Ireland

[2] Dublin Inst Technol, FOCAS Inst, Kevin St, Dublin 8, Ireland

[3] Dublin City Univ, Natl Ctr Sensor Res, INSIGHT Ctr Data Analyt, Dublin 9, Ireland

[4] Univ Basque Country UPV EHU, Dept Analyt Chem, Microfluid UPV EHU Cluster, Analyt Microsyst & Mat Lab On A Chip Grp AMMa LOA, Vitoria, Spain

[5] Univ Genoa, Dept Informat Bioengn Robot & Syst Engn, Genoa, Italy

关键词: Microcantilever sensors;    Surface stress;    Nanomechanics;    Molecular switch;    Spiropyran;    Photochromism;   

DOI  :  10.1016/j.snb.2016.06.108

来源: Elsevier

【 摘 要 】

Herein we investigate the feasibility of detecting photo-induced surface stress changes using the deflection response of cantilevers. For this purpose, silicon microcantilevers have been functionalised with spiropyran photochromic molecules, using both a monolayer and a polymeric brushes approach. Upon ultraviolet light irradiation, the spiropyran unit is converted to the merocyanine form due to the photoinduced cleavage of the C-spiro-O bond. The two forms of the molecule have dramatically different charge, polarity and molecular conformations. This makes spiropyrans an ideal system to study the correlation between photo-induced molecular changes and corresponding changes in surface stress. Our investigations include monitoring the changes in static cantilever deflection, and consequently, surface stress of the spiropyran functionalised cantilevers on exposure to ultraviolet light. Cantilever deflection data reveals that ultraviolet induced conformational changes in the spiropyran moiety cause a change in compressive surface stress and this varies with the type of functionalisation method implemented. The change in surface stress response from the spiropyran polymer brushes functionalised cantilevers gives an average surface stress change of 98 Nm(-1)(n = 24) while the spiropyran monolayer coated cantilevers have an average surface stress change of about 446 Nm(-1) (n = 8) upon irradiation with UV light. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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