A simple and reproducible method was developed to synthesize a novel class of Co-B/SiO2/dye/SiO2 composite core/shell particles. Using a single cobalt core, Rhodamine 6G of organic dye molecules was entrapped in a silica shell, resulting in core/shell particles of similar to 200 nm diameter. Analyses using a variety of techniques such as transmission electron microscopy, X-ray photoelectron spectroscopy, vibration sample magnetometry, confocal laser scanning microscopy, and fluorescence intensity demonstrated that dye molecules were trapped inside the core/shell particles. A photoluminescence investigation showed that highly luminescent and photostable core/shell particles were formed. Such core/shell particles can be easily suspended in water. The synthesized magnetic particles could be used to detect fluorescence on glass substrate arrays for bioassay and biosensor applications. (C) 2012 Elsevier Ltd. All rights reserved.