A series of fluorescent silica nanoparticle (SNP) chemosensors were produced in three to four synthetic steps by various chemically activating surface modifiers, such as APTES with poly(amidoamine) (PAMAM) dendrimers in order to anchor fluorescent dyes. The architecture and size of the nanoparticle surface determined the density of functional sites and dispersibility, while the PAMAM dendrimers provided both non-covalent and covalent binding sites for some analytes and aided in the dispersibility of SNPs in polar solvents. Two types of SNPs were created: SNP-Dye1-Dendrimer-Dye2 and SNP-Dendrimer-Dye. These particles were isolated using centrifugation and lyophilization. The SNPs were then characterized via Ninhydrin assay (amine density), dye loading, and Forster Resonance Energy Transfer (FRET) between dyes using spectrophotometry and fluorimetry respectively. The double dye SNP employs the dendrimer as a spacer to separate the dyes for applications of FRET quenching (by an acceptor such as Cu2+) or ratiometric sensing. We will present results for characterization and quenching studies along with preliminary results from FRET studies.

Synthesis, characterization, and application of dendrimer coated silica nanoparticles as fluorescent chemosensors

253rd National Meeting (2017)

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