[1] Wang, Z. J., Li, Z. Y., Jiang, T. T., Xu, X. R. & Wang, C. Ultrasensitive hydrogen sensor based on Pd0-loaded SnO2 electrospun nanofibers at room temperature. ACS Appl. Mater. Interfaces 5, 2013-2021 (2013). doi: 10.1021/am3028553
[2] Schutter, F. D. et al. Proton conductivity in strontium cerates for hydrogen gas sensors in coal gasification systems. Solid State Ion. 57, 77-81 (1992). doi: 10.1016/0167-2738(92)90066-X
[3] Hübert, T., Boon-Brett, L., Black, G. & Banach, U. Hydrogen sensors - a review. Sens Actuators B: Chem. 157, 329-352 (2011). doi: 10.1016/j.snb.2011.04.070
[4] Yu, S. F. et al. Fabrication of palladium nanotubes and their application in hydrogen sensing. Chem. Mater. 17, 3445-3450 (2005). doi: 10.1021/cm048191i
[5] Favier, F., Walter, E. C., Zach, M. P., Benter, T. & Penner, R. M. Hydrogen sensors and switches from electrodeposited palladium mesowire arrays. Science 293, 2227-2231 (2001). doi: 10.1126/science.1063189
[6] Yang, F., Taggart, D. K. & Penner, R. M. Fast, sensitive hydrogen gas detection using single palladium nanowires that resist fracture. Nano. Lett. 9, 2177-2182 (2009). doi: 10.1021/nl9008474
[7] Jeon, K. J., Lee, J. M., Lee, E. & Lee, W. Individual Pd nanowire hydrogen sensors fabricated by electron-beam lithography. Nanotechnology 20, 135502 (2009). doi: 10.1088/0957-4484/20/13/135502
[8] Zeng, X. Q. et al. Networks of ultrasmall Pd/Cr nanowires as high performance hydrogen sensors. ACS Nano 5, 7443-7452 (2011). doi: 10.1021/nn2023717
[9] Lee, E., Lee, J. M., Koo, J. H., Lee, W. & Lee, T. Hysteresis behavior of electrical resistance in Pd thin films during the process of absorption and desorption of hydrogen gas. Int. J. Hydrog. Energy 35, 6984-6991 (2010). doi: 10.1016/j.ijhydene.2010.04.051
[10] Lee, E. et al. Hydrogen gas sensing performance of Pd-Ni alloy thin films. Thin. Solid. Films. 519, 880-884 (2010). doi: 10.1016/j.tsf.2010.07.122
[11] Lee, J., Shim, W., Lee, E., Noh, J. S. & Lee, W. Highly mobile palladium thin films on an elastomeric substrate: Nanogap‐based hydrogen gas sensors. Angew. Chem. Int Ed. 50, 5301-5305 (2011). doi: 10.1002/anie.201100054
[12] Lee, J. et al. Cracked palladium films on an elastomeric substrate for use as hydrogen sensors. Int. J. Hydrog. Energy 37, 7934-7939 (2012). doi: 10.1016/j.ijhydene.2012.01.067
[13] Vargas, W. E., Rojas, I., Azofeifa, D. E. & Clark, N. Optical and electrical properties of hydrided palladium thin films studied by an inversion approach from transmittance measurements. Thin. Solid. Films. 496, 189-196 (2006). doi: 10.1016/j.tsf.2005.08.346
[14] Fortunato, G., Bearzotti, A., Caliendo, C. & D'Amico, A. Hydrogen sensitivity of Pd/SiO2/Si structure: a correlation with the hydrogen-induced modifications on optical and transport properties of α-phase Pd films. Sens Actuators 16, 43-54 (1989). doi: 10.1016/0250-6874(89)80004-6
[15] Chtanov, A. & Gal, M. Differential optical detection of hydrogen gas in the atmosphere. Sens Actuators B: Chem. 79, 196-199 (2001). doi: 10.1016/S0925-4005(01)00875-9
[16] Zhao, Z., Carpenter, M. A., Xia, H. & Welch, D. All-optical hydrogen sensor based on a high alloy content palladium thin film. Sens Actuators B: Chem. 113, 532-538 (2006). doi: 10.1016/j.snb.2005.03.070
[17] Villatoro, J. & Monzón-Hernández, D. Fast detection of hydrogen with nano fiber tapers coated with ultra thin palladium layers. Opt. Express 13, 5087-5092 (2005). doi: 10.1364/OPEX.13.005087
[18] Pasturel, M. et al. Stabilized switchable "black state" in Mg2NiH4∕Ti∕Pd thin films for optical hydrogen sensing. Appl. Phys. Lett. 89, 021913 (2006). doi: 10.1063/1.2221412
[19] Slaman, M. et al. Fiber optic hydrogen detectors containing Mg-based metal hydrides. Sens Actuators B: Chem. 123, 538-545 (2007). doi: 10.1016/j.snb.2006.09.058
[20] Nasir, M. E., Dickson, W., Wurtz, G. A., Wardley, W. P. & Zayats, A. V. Hydrogen detected by the naked eye: optical hydrogen gas sensors based on core/shell plasmonic nanorod metamaterials. Adv. Mater. 26, 3532-3537 (2014). doi: 10.1002/adma.201305958
[21] Tittl, A. et al. Palladium-based plasmonic perfect absorber in the visible wavelength range and its application to hydrogen sensing. Nano. Lett. 11, 4366-4369 (2011). doi: 10.1021/nl202489g
[22] Bagheri, S. et al. Large-Area low-cost plasmonic perfect absorber chemical sensor fabricated by laser interference lithography. ACS Sens 1, 1148-1154 (2016). doi: 10.1021/acssensors.6b00444
[23] Liu, N., Tang, M. L., Hentschel, M., Giessen, H. & Alivisatos, A. P. Nanoantenna-enhanced gas sensing in a single tailored nanofocus. Nat. Mater. 10, 631-636 (2011). doi: 10.1038/nmat3029
[24] Shegai, T., Johansson, P., Langhammer, C. & Käll, M. Directional scattering and hydrogen sensing by bimetallic Pd-Au nanoantennas. Nano. Lett. 12, 2464-2469 (2012). doi: 10.1021/nl300558h
[25] Langhammer, C., Larsson, E. M., Kasemo, B. & Zorić, I. Indirect nanoplasmonic sensing: ultrasensitive experimental platform for nanomaterials science and optical nanocalorimetry. Nano. Lett. 10, 3529-3538 (2010). doi: 10.1021/nl101727b
[26] Jiang, R. B., Qin, F., Ruan, Q. F., Wang, J. F. & Jin, C. J. Ultrasensitive plasmonic response of bimetallic Au/Pd nanostructures to hydrogen. Adv. Funct. Mater. 24, 7328-7337 (2014). doi: 10.1002/adfm.201402091
[27] Tang, M. L., Liu, N., Dionne, J. A. & Alivisatos, A. P. Observations of shape-dependent hydrogen uptake trajectories from single nanocrystals. J. Am. Chem. Soc. 133, 13220-13223 (2011). doi: 10.1021/ja203215b
[28] Chiu, C. Y. & Huang, M. H. Polyhedral Au-Pd core-shell nanocrystals as highly spectrally responsive and reusable hydrogen sensors in aqueous solution. Angew. Chem. Int Ed. 52, 12709-12713 (2013). doi: 10.1002/anie.201306363
[29] Yanik, A. A. et al. Seeing protein monolayers with naked eye through plasmonic Fano resonances. Proc. Natl Acad. Sci. USA 108, 11784-11789 (2011). doi: 10.1073/pnas.1101910108
[30] Hoang, A. T., Cho, Y. B., Park, J. S., Yang, Y. & Kim, Y. S. Sensitive naked-eye detection of gaseous ammonia based on dye-impregnated nanoporous polyacrylonitrile mats. Sens Actuators B: Chem. 230, 250-259 (2016). doi: 10.1016/j.snb.2016.02.058
[31] Ngene, P. et al. Seeing hydrogen in colors: low‐cost and highly sensitive eye readable hydrogen detectors. Adv. Funct. Mater. 24, 2374-2382 (2014). doi: 10.1002/adfm.201303065
[32] Baldi, A. et al. Quasifree Mg-H thin films. Appl. Phys. Lett. 95, 071903 (2009). doi: 10.1063/1.3210791
[33] Pivak, Y. et al. Effect of the substrate on the thermodynamic properties of PdHx films studied by hydrogenography. Scr. Mater. 60, 348-351 (2009). doi: 10.1016/j.scriptamat.2008.11.012
[34] Shen, Y., She, X. Y. & Jin, C. J. Mechanically reconfigurable Pd nanogroove array: an ultrasensitive optical hydrogen detector. ACS Photonics 5, 1334-1342 (2018). doi: 10.1021/acsphotonics.7b01323
[35] Wang, Y. et al. Wearable and Highly Sensitive Graphene Strain Sensors for Human Motion Monitoring. Adv. Funct. Mater. 24, 4666-4670 (2014). doi: 10.1002/adfm.201400379
[36] Yao, S. S. & Zhu, Y. Wearable multifunctional sensors using printed stretchable conductors made of silver nanowires. Nanoscale 6, 2345-2352 (2014). doi: 10.1039/c3nr05496a
[37] Gong, S. et al. A wearable and highly sensitive pressure sensor with ultrathin gold nanowires. Nat. Commun. 5, 3132 (2014). doi: 10.1038/ncomms4132
[38] Pang, C., Lee, C. & Suh, K. Y. Recent advances in flexible sensors for wearable and implantable devices. J. Appl. Polym. Sci. 130, 1429-1441 (2013). doi: 10.1002/app.39461
[39] Fuard, D., Tzvetkova-Chevolleau, T., Decossas, S., Tracqui, P. & Schiavone, P. Optimization of poly-di-methyl-siloxane (PDMS) substrates for studying cellular adhesion and motility. Microelectron. Eng. 85, 1289-1293 (2008). doi: 10.1016/j.mee.2008.02.004
[40] Silkin, V. M., Diez Muiño, R., Chernov, I. P., Chulkov, E. V. & Echenique, P. M. Tuning the plasmon energy of palladium-hydrogen systems by varying the hydrogen concentration. J. Phys: Condens Matter 24, 104021 (2012). doi: 10.1088/0953-8984/24/10/104021
[41] Chu, T. X. et al. Comparison between measurements of elasticity and free amino group content of ovalbumin microcapsule membranes: Discrimination of the cross-linking degree. J. Colloid Interface Sci. 355, 81-88 (2011). doi: 10.1016/j.jcis.2010.11.038
[42] Manchester, F. D., San-Martin, A. & Pitre, J. M. The H-Pd (hydrogen-palladium) system. J. Phase Equilib. 15, 62-83 (1994). doi: 10.1007/BF02667685
[43] Qin, D., Xia, Y. N. & Whitesides, G. M. Soft lithography for micro-and nanoscale patterning. Nat. Protoc. 5, 491-502 (2010). doi: 10.1038/nprot.2009.234