Dual-fluorophore Raspberry-like Nanohybrids for Ratiometric pH Sensing

Isaac Acquah, Jinkyu Roh, Dong June Ahn

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


We report on the development of raspberry-like silica structures formed by the adsorption of 8-hydroxypyrene-1,3,6-trisulfonate (HPTS)@silica nanoparticles (NPs) on rhodamine B isothiocyanate (RBTIC)@silica NPs for ratiometric fluorescence-based pH sensing. To overcome the well-known problem of dye leaching which occurs during encapsulation of anionic HPTS dye in silica NPs, we utilized a polyelectrolyte-assisted incorporation of the anionic HPTS. The morphological and optical characterization of the as-synthesized dye-doped NPs and the resulting nanohybrids were carried out. The pH-sensitive dye, HPTS, incorporated in the HPTS-doped silica NPs provided a pH-dependent fluorescence response while the RBITC-doped silica provided the reference signal for ratiometric sensing. We evaluated the effectiveness of the nanohybrids for pH sensing; the ratio of the fluorescence emission intensity at 510 nm and 583 nm at excitation wavelengths of 454 nm and 555 nm, respectively. The results showed a dynamic response in the acidic pH range. With this approach, nanohybrids containing different dyes or receptors could be developed for multifunctioning and multiplexing applications.

Original languageEnglish
Pages (from-to)1724-1729
Number of pages6
JournalChemistry - An Asian Journal
Issue number14
Publication statusPublished - 2017 Jul 18


  • dual-fluorophore
  • polyelectrolyte
  • raspberry structure
  • ratiometric pH sensors
  • silica nanohybrids

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry


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