Stimuli-Responsive Multilayered Hybrid Nanoparticle/Polyelectrolyte Capsules

✍ Scribed by Bruno G. De Geest; Andrei G. Skirtach; Thomas R. M. De Beer; Gleb B. Sukhorukov; Lieven Bracke; Willy R. G. Baeyens; Joseph Demeester; Stefaan C. De Smedt

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 333 KB
• Volume: 28
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200600631

✦ Synopsis

Abstract

Gold nanoparticles (Au~NP~) with carboxyl groups on their surface were used in combination with PAH for the layer‐by‐layer coating of CaCO~3~ microparticles, followed by the dissolution of the CaCO~3~ core. SEM, TEM, and confocal microscopy are used to characterize the hybrid nanoparticles/polyelectrolyte capsules. As the Au~NP~ have carboxyl groups on their surface, their charge density is pH dependent; therefore, the capsules exhibit a pH‐dependent swelling and can be deconstructed both at low and high pH. By covalent cross‐linking of the carboxyl groups of the Au~NP~ and the amino groups of the PAH, it is possible to suppress the pH‐responsive behavior. Au~NP~ are used as activation centers using IR light and this ability is used to release encapsulated material from the nanoparticles/polyelectrolyte capsules as well as for the enhancement of detection and imaging of such capsules by Raman microspectrosopy.

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