Fluorescence dye-functionalized Janus particles were synthesized for the asymmetric particle self-assembly and the reversible Forster Resonance Energy Transfer (FRET) A Janus particle cored with a 500 nm silica colloid was bi-functionalized with the amino-silane on one of its hemispheric surface and a fluorescence dye Marina Blue attached to this hemispheric surface These Janus particles in the submicron scale were carefully fabricated and characterized following the prior works Commercially-available polyacrylonitrile (PAN) nanobeads with 80 nm in diameter and carboxylic surface-functionalities were employed as the self-assembly counterpart These PAN nanobeads also contained a fluorescence dye Chromeon 470 to be utilized as the FRET acceptor while the Marina Blue Janus particles served as the FRET donor Self-assembly of these two particles in an aqueous solution was performed by the positively-charged asymmetric 500 nm Janus particles and the negatively-charged 80 nm PAN nanobeads The sizes of the assembled clusters were monitored by the dynamic light scattering (DLS) Successful FRET was confirmed by the 365 nm excitation to the Marina Blue Janus particles accompanied by the 611 nm emission of Chromeon 470 nanobeads Variation of the particle ratios also resulted in the proportional FRET effects Reversible particle self-assembly was also investigated by the introduction of ultrasonic treatment that separated the assembled clusters Time-resolved FRET and DLS with the reversible particle self-assembly and the assembly correlation time revealed the asymmetric particle self-assembly from Janus particles and the assembly-dependent FRET performance
Reversible FRET Induced by the Self-assembly of Dye-functionalized Janus Particles
祖瑞, 梁. (Author). 2014 8月 26
學生論文: Master's Thesis