ORALS

SESSION: CompositeMonPM1-R8	6th Intl. Symp. on Composite, Ceramic and Nano Materials Processing, Characterization and Applications
Mon Nov, 5 2018 / Room: Grego (50/3rd)
Session Chairs: Raman Singh; Gabor Patonay; Session Monitor: TBA

14:50: [CompositeMonPM107]
How to Generate More Fluorescence with Less: Silica Nanoparticle Encapsulated Dyes
Gabor Patonay¹ ; Eman Alsolmy¹ ; Maged Henary¹ ; Walid Abdelwahab¹ ; Gala Chapman¹ ; ¹Georgia State University, Atlanta, United States;
Paper Id: 227 [Abstract]

The use of fluorescence in many chemical applications often requires extrinsic fluorophores, especially when intrinsic fluorescence of the molecule of interest is weak or in a spectral region that is prone to interference in the matrix. Introducing extrinsic fluorophores in the molecule of interest may require chemistry that utilizes a reagent that is less environmentally friendly or may require significant amounts of the fluorescent dyes. This is especially true if a fluorophore is used to authenticate the origin of industrial products, such as hydrocarbons, paints, etc. This is due to the fact that the fluorescence intensity of a single molecular label or reporting group can be relatively weak, requiring a larger amount of chemicals per unit product. Frequently the product itself may cause quenching of the fluorophore. All these concerns may be alleviated by encapsulating fluorophores in silica nanoparticles. Silica nanoparticles are biologically and environmentally friendly and can be designed for many applications. Covalently copolymerized dyes in silica nanoparticles are free from leaching; even non-covalently encapsulated dyes are often virtually free of leaching. The outside of the silica nanoparticles can be designed to mach the product chemistry, and can be hydrophobic or hydrophilic or anything between. The encapsulated dye can serve as a simple reporting label or as a sophisticated molecular probe. Due to the large number of dye molecules that can be encapsulated in a single silica nanoparticle, the number of labels are very small, requiring minimal amount of chemicals. Silica nanoparticle synthesis is conducive for the introduction of covalently copolymerized fluorescent dyes by using modified TEOS reactive analogues that are inexpensive and widely available. The outside layer of the silica nanoparticle surface that can be modified by regrowth technique can also serve as chemical reagent or sensor. This study reports how copolymerized silica nanoparticles can be made using a wide array of fluorophores and how its surface properties were modified by adding hydrophobic or hydrophilic molecules to achieve compatibility. Surface hydrophobicity controlled fluorescent silica nanoparticles are excellent candidates for many applications, including sensitive analytical detections. Copolymerization of multiple dyes or other molecules will also be discussed to achieve large Stokes' shift using fluorescence energy transfer.

References:
[1] Patonay G, Beckford G, HAänninen P. UV-Vis and NIR Fluorescence Spectroscopy, in Handbook of Spectroscopy: Second, Enlarged Edition, Wiley-VCH Verlag GmbH & Co. KGaA, Published Online: 2 APR 2014, DOI: 10.1002/ 9783527654703. ch26.
[2] Patonay G, Chapman G, Beckford G, Henary M, Ellis M. Use of Fluorescent NIR Dyes in Silica Nanoparticles and as Enzyme Substrates in Bioanalytical Applications, Proc. SPIE. 8956, 89560U /1-89560U/11 (2014).
[3] Chapman G, Solomon I, Patonay G, Henary M. Synthesis and pH-Dependent Spectroscopic Behavior of 2,4,6-Trisubstituted Pyridine Derivatives, J. of Heterocyc Chem (52) 3, 861-872 (2015).
[4] Ebeid WM, Salim MM, Elkady EF, Asmaa A, Ramzia A, El-Bagary Patonay G. Simultaneous Determination of Valsartan, Amlodipine besylate and Hydrochlorothiazide using CZE in their Combined Dosage Form, PHARMAZIE, 70, 368-373, (2015).
5. Patonay G, Henary M, Chapman G, Emer K, Crow S, Fluorescent silica nanoparticles containing covalently bound dyes for reporter, marker, and sensor applications Proc. SPIE. 97230Q; doi:10.1117/12.2217869 (2016).