Temperature Controlled Fluorescence on Au@Ag@PNIPAM-PTEBS Microgels: Effect of the Metal Core Size on the MEF Extension

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• 作者：Rafael Contreras-Caceres ; Paulino Alonso-Cristobal ; Diego Mendez-Gonzalez ; Marco Laurenti ; Ana Maldonado-Valdivia ; Francisco Garcia-Blanco ; Enrique L贸pez Cabarcos ; Antonio Fernandez-Barbero ; Jos茅 Manuel Lopez-Romero ; Jorge Rubio-Retama
• 刊名：Langmuir
• 出版年：2014
• 出版时间：December 30, 2014
• 年：2014
• 卷：30
• 期：51
• 页码：15560-15567
• 全文大小：462K
• ISSN：1520-5827

文摘

In this work, we present a novel method to produce thermoresponsive, monodisperse microgels which display temperature-dependent photoluminescence. The system is based on bimetallic cores of Au@Ag encapsulated within thermoresponsive poly(N-isopropylacrylamide) microgels and coated with a photoluminescent polymer (poly[2-(3-thienyl)ethoxy-4-butylsulfonate] (PTEBS) using the Layer-by-Layer technique. The electromagnetic radiation used to excite the PTEBS induces a local electromagnetic field on the surface of the bimetallic cores that enhances the excitation and emission rates of the PTEBS, yielding a metal enhanced fluorescence (MEF). This effect was studied as a function of the bimetallic core size and the separation distance between the PTEBS and the bimetallic cores. Our results permit evaluation of the effect that the metallic core size of colloidal particles exerts on the MEF for the first time, and prove the relevance of the metallic cores to extend the effect far away from the metallic surface.