Controlled In Situ Seed-Mediated Growth of Gold and Silver Nanoparticles on an Optical Fiber Platform for Plasmonic Sensing Applications
- 30 Downloads
This study presents an in situ growth technique to develop highly sensitive plasmonic fiber optic sensors with an excellent control over the plasmonic properties of gold (AuNPs) and silver nanoparticles (AgNPs). Here, we exploit the dual functionality of the U-bent fiber optic sensor (FOS) probes, where the probe acts as, firstly, the substrate for nanoparticles’ growth and, secondly, an invaluable tool to monitor as well as control the gold and silver seed binding to the surface amine groups and subsequently their growth in real time by means of the evanescent wave absorbance (EWA) spectral response. Au and Ag seeds (< 5 nm) with a peak absorbance at 510 and 390 nm, respectively, were used. The NP growth kinetics from the probes for different seed densities with a peak EWA response of 0.05, 0.1, and 0.15 optical density (OD) were observed in the presence of the respective metal precursor, cetyltrimethylammonium bromide (CTAB), and ascorbic acid. In comparison with AuNP grown FOS, a significant anisotropic growth was observed for AgNP with a redshift and spectral width as high as 215 nm and 425 nm, respectively, for a peak EWA response of 2.0 OD. The localized surface plasmon resonance (LSPR) activity of the AuNPs and AgNP grown FOS probes was evaluated for seed density of 0.1 OD. These proof-of-the-concept studies show significantly high RI sensitivity and surface-enhanced Raman scattering (SERS) enhancement factor for AgNP probes at 15.8 ΔA/RIU (for 22 AgNPs/μm2) and 1.3 × 107, respectively, in comparison with 18.9 ΔA/RIU (for 1424 AuNPs/μm2) and 1.1 × 106, respectively, for AuNP FOS probes. In addition, these plasmonic probes were stable in organic solvent (hexane) but its stability was deteriorated in alkaline solution (1 M NaOH).
KeywordsPlasmonic fiber optic sensor Gold and silver nanoparticles Seed-mediated growth LSPR SERS Chemical stability
The authors thank Prof. A. Subrahmanyam (Department of Physics, Indian Institute of Technology Madras) for giving access to UV-visible and Raman spectrometer facility. We also acknowledge HR-SEM facility in Chemical Engineering, IIT Madras, funded by FIST grant from the Department of Science and Technology, Government of India. Hariharan Manoharan acknowledges the PhD scholarship from the Ministry of Human Resource Development, Government of India.
- 7.Huang Y, Zhu W, Li Z, Chen G, Chen L, Zhou J, Lin H, Guan J, Fang W, Liu X, Dong H, Tang J, Guan H, Lu H, Xiao Y, Zhang J, Wang H, Chen Z, Yu J (2018) High-performance fibre-optic humidity sensor based on a side-polished fibre wavelength selectively coupled with graphene oxide film. Sensors Actuators B Chem 255:57–69. https://doi.org/10.1016/j.snb.2017.08.042 CrossRefGoogle Scholar
- 10.Velázquez-González JS, Monzón-Hernández D, Moreno-Hernández D, Martínez-Piñón F, Hernández-Romano I (2017) Simultaneous measurement of refractive index and temperature using a SPR-based fiber optic sensor. Sensors Actuators B Chem 242:912–920. https://doi.org/10.1016/j.snb.2016.09.164 CrossRefGoogle Scholar
- 23.Jana NR, Gearheart L, Murphy CJ (2001) Wet chemical synthesis of silver nanorods and nanowires of controllable aspect ratio. Chem Commun:617–618. https://doi.org/10.1039/b100521i
- 28.Spasopoulos D, Kaziannis S, Karantzalis AE, Lidorikis E, Ikiades A, Kosmidis C (2017) Tailored aggregate-free Au nanoparticle decorations with sharp plasmonic peaks on a U-type optical fiber sensor by nanosecond laser irradiation. Plasmonics 12:535–543. https://doi.org/10.1007/s11468-016-0295-1 CrossRefGoogle Scholar