Gold Sputtered U-Bent Plastic Optical Fiber Probes as SPR- and LSPR-Based Compact Plasmonic Sensors
- 336 Downloads
This study describes fabrication of highly sensitive surface plasmon resonance (SPR) as well as localized SPR (LSPR) dominant fiber optic plasmonic probes by controlled sputtering of gold thin films on the fiber core surface. Compact U-bent probes of 750 μm plastic optical fibers (made of poly(methylmethacrylate) (PMMA)) were used for efficient evanescent wave excitation of plasmonic substrates to achieve high sensitivity. U-bent probes with 2.25-mm bend diameter were sputter coated for deposition times of 30, 60, 90, and 120 s to obtain gold thin films with nanovoids on the U-bent region. As deposition time increased, a significant transition from LSPR to SPR characteristics was observed in the overall UV-visible spectral characteristics with a clear shift in the plasmon peak from 520 to 650 nm. Probes sputtered for 30 and 120 s show excellent LSPR- and SPR-based characteristics with a sensitivity of 15.5 ∆Abs/RIU and 1040 nm/RIU, respectively (for refractive index variation from 1.333 to 1.361 RIU). The high sensitivity of the probes in addition to other advantages, including ease of fabrication, cost-effectiveness, and suitability for in situ monitoring, demonstrates their potential for bio/chemical sensing applications.
KeywordsU-bent fiber optic sensors Gold sputtering Plasmonic nanostructures Plastic optical fiber Refractive index sensing
We thank Mitsubishi Rayon Co., Ltd., Japan, for providing POF samples. We acknowledge the SEM facility in the Department of Chemical Engineering, IIT Madras for EDX spectra; SEM facility in Department of Mechanical Engineering, York University, Toronto, for SEM images; and INUP, IIT Bombay, for profilometer measurements.
Compliance with Ethical Standards
The authors declare that they have no competing interests.
- 7.Zeni L, Auria SD, Pesavento M et al (2015) Sensing platforms exploiting surface plasmon resonance in polymeric optical fibers for chemical and biochemical applications. Adv Photonics:6–8Google Scholar
- 14.Pesavento M, Cennamo N, Donà A, et al. (2014) A new approach for selective optical fiber sensors based on localized surface plasmon resonance of gold nanostars in molecularly imprinted polymer. In: Recent Adv. Biomed. Chem. Eng. Mater. Sci. Venice, Italy, March 15‐17, 2014. pp 71–75Google Scholar
- 15.He Y, Fu J, Zhao Y (2014) Oblique angle deposition and its applications in plasmonics. Front Phys 9(1):47–59. doi: 10.1007/s11467-013-0357-1
- 16.Siegel J, Kvítek O, Kolská Z, Slepička P, Švorčík V (2012) Gold nanostructures prepared on solid surface. Metall - Adv Mater Process:44–70. doi: 10.5772/51617
- 21.Freund LB, Suresh S (2004) Modes of film growth by vapor deposition. In: Thin film materials: stress, defect formation and surface evolution Cambridge University Press, New York. pp 15–29Google Scholar
- 30.Brito PCA, Souza TXR, Gomes RF et al (2011) Au/Ag nanostructures on PMMA surface. Sci Plena 7:2–6Google Scholar
- 31.Cole RM, Baumberg JJ, Abajo FJG De, et al. (2007) Understanding plasmons in nanoscale voids. Nano letters 7(7):2094–2100Google Scholar
- 33.Cennamo N, Zeni L (2014) Bio and chemical sensors based on surface plasmon resonance in a plastic optical fiber. In: Opt. Sensors - New Dev. Pract. Appl. Intech. Rijeka, Intech. pp 119–140Google Scholar
- 34.Jun S, Leong C, Gyu H et al (2013) Optical fiber sensor for refractive index measurement based on localized surface Plasmon resonance. Conf Lasers Electro-Optics Pacific Rim WPF-20:2–3Google Scholar
- 39.Cao J, Galbraith EK, Sun T, Grattan KT V (2012) Cross-comparison of surface plasmon with different coating structures 12:2355–2361.Google Scholar
- 41.Christopher CGC, Vasanthakumari P, Annasamy G, et al. (2016) SERS based sandwich immunosensing with plasmonically active plastic optical fiber sensor probes. In: Adv. Photonics 2016 (IPR, NOMA, Sensors, Networks, SPPCom, SOF). Optical Society of America, p SeW3E.7Google Scholar