1. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Flow chart of the basic synthesis procedure of fabricating composite xerogel with embedded Ru(dpp) 3 2+ and dye-entrapped core- shell silica nanoparticles. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

2. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. TEM image of Ru(dpp) 3 2+ -entrapped core-shell silica particle. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

3. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Schematic diagram of experimental arrangement used for characterization. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

4. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Electronic circuits of proposed portable optical oxygen sensor. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

5. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Photograph of the sensor module in the proposed portable oxygen sensor. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

6. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Calibration curve obtained for oxygen concentrations of 0 to 100%. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

7. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Stern–Volmer plots of proposed portable optical oxygen sensor for oxygen concentrations of (a) 0 to 100% and (b) 0 to 60%. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112

8. Date of download: 9/18/2016 Copyright © 2016 SPIE. All rights reserved. Effects of aging on the average response stability. Figure Legend: From: Portable optical oxygen sensor based on Ru(II) complex and dye entrapped core- shell nanoparticles embedded in sol-gel matrix coated on a photodiode Opt. Eng. 2011;50(5):054404-054404-6. doi:10.1117/1.3581112