[1] Ghoneim, M. T., et al. Recent progress in electrochemical ph-sensing materials and configurations for biomedical applications. Chemical reviews 119, 5248-5297 (2019). doi: 10.1021/acs.chemrev.8b00655
[2] Gu th, U., Vonau, W. & Zosel, J. Recent developments in electrochemical sensor application and technology—a review. Measurement Science and Technology 20, 042002 (2009). doi: 10.1088/0957-0233/20/4/042002
[3] Wencel, D., Ab el, T. & McDonagh, C. Optical chemical pH sensors. Analytical chemistry 86, 15-29 (2014). doi: 10.1021/ac4035168
[4] H ou, J. T., et al. Fluorescent bioimaging of pH: From design to applications. Chemical Society reviews 46, 2076-2090 (2017). doi: 10.1039/C6CS00719H
[5] Steinegger, A., Wolfbeis, O. S. & Borisov, S. M. Optical sensing and imaging of pH values: Spectroscopies, materials, and applications. Chemical reviews 120, 12357-12489 (2020). doi: 10.1021/acs.chemrev.0c00451
[6] Zubiate, P., et al. Tunable optical fiber pH sensors based on TE and TM lossy mode resonances (LMRs). Sensors and Actuators B: Chemical 231, 484-490 (2016). doi: 10.1016/j.snb.2016.03.024
[7] Kozlovskaya, V., et al. Ultrathin layer-by-layer hydrogels with incorporated gold nanorods as pH-sensitive optical materials. Chemistry of Materials 20, 7474-7485 (2008). doi: 10.1021/cm8023633
[8] H u, P. B., et al. Photonic crystal fiber interferometric pH sensor based on polyvinyl alcohol/polyacrylic acid hydrogel coating. Applied optics 54, 2647-2652 (2015). doi: 10.1364/AO.54.002647
[9] X u, Y., et al. Optical refractive index sensors with plasmonic and photonic structures: Promising and inconvenient truth. Advanced Optical Materials 7, 1801433 (2019). doi: 10.1002/adom.201801433
[10] Loyez, M., et al. From whispering gallery mode resonators to biochemical sensors. ACS sensors 8, 2440-2470 (2023). doi: 10.1021/acssensors.2c02876
[11] Braginsky, V. B., Gorodetsky, M. L. & Ilchenko, V. S. Quality-factor and nonlinear properties of optical whispering-gallery modes. Physics Letters A 137, 393-397 (1989). doi: 10.1016/0375-9601(89)90912-2
[12] Vahala, K. J. Optical microcavities. Nature 424, 839-846 (2003). doi: 10.1038/nature01939
[13] Jiang, X. F., et al. Whispering-gallery sensors. Matter 3, 371-392 (2020). doi: 10.1016/j.matt.2020.07.008
[14] Foreman, M. R., Swaim, J. D. & Vollmer, F. Whispering gallery mode sensors. Advances in optics and photonics 7, 168-240 (2015). doi: 10.1364/AOP.7.000168
[15] C ai, L., et al. Whispering gallery mode optical microresonators: Structures and sensing applications. physica status solidi (a) 217, 1900825 (2020). doi: 10.1002/pssa.201900825
[16] Y u, D. S., et al. Whispering-gallery-mode sensors for biological and physical sensing. Nature Reviews Methods Primers 1, 83 (2021). doi: 10.1038/s43586-021-00079-2
[17] Ko ch, B., et al. Reflection-mode sensing using optical microresonators. Applied Physics Letters 95, 201111 (2009). doi: 10.1063/1.3263143
[18] Knittel, J., et al. Back-scatter based whispering gallery mode sensing. Scientific reports 3, 2974 (2013). doi: 10.1038/srep02974
[19] Ch en, Y. P., et al. Recent progress on optoplasmonic whispering–gallery–mode microcavities. Advanced Optical Materials 9, 2100143 (2021). doi: 10.1002/adom.202100143
[20] Serrano, M. P., et al. ”Grafting-To” covalent binding of plasmonic nanoparticles onto silica WGM microresonators: Mechanically robust single-molecule sensors and determination of activation energies from single-particle events. Sensors 23, 3455 (2023). doi: 10.3390/s23073455
[21] Reynolds, T., et al. Fluorescent and lasing whispering gallery mode microresonators for sensing applications. Laser & Photonics Reviews 11, 1600265 (2017).
[22] Toropov, N., et al. Review of biosensing with whispering-gallery mode lasers. Light: Science & Applications 10, 42 (2021).
[23] Ch en, W. J., et al. Exceptional points enhance sensing in an optical microcavity. Nature 548, 192-196 (2017). doi: 10.1038/nature23281
[24] Vollmer, F., et al. Protein detection by optical shift of a resonant microcavity. Applied Physics Letters 80, 4057-4059 (2002). doi: 10.1063/1.1482797
[25] Xi ao, Y. F., Gaddam, V. & Yang, L. Coupled optical microcavities: An enhanced refractometric sensing configuration. Optics express 16, 12538-12543 (2008). doi: 10.1364/OE.16.012538
[26] C ai, L., et al. Fano resonance in whispering gallery mode microcavities and its sensing applications. Optics & Laser Technology 167, 109679 (2023).
[27] Saetchnikov, A. V., et al. Deep-learning powered whispering gallery mode sensor based on multiplexed imaging at fixed frequency. Opto-Electronic Advances 3, 200048 (2020). doi: 10.29026/oea.2020.200048
[28] Saetchnikov, A. V., et al. Intelligent optical microresonator imaging sensor for early stage classification of dynamical variations. Advanced Photonics Research 2, 2100242 (2021). doi: 10.1002/adpr.202100242
[29] Özel, B., et al. Temperature sensing by using whispering gallery modes with hollow core fibers. Measurement Science and Technology 21, 094015 (2010). doi: 10.1088/0957-0233/21/9/094015
[30] S u, J., Goldberg, A. F. & Stoltz, B. M. Label-free detection of single nanoparticles and biological molecules using microtoroid optical resonators. Light: Science & Applications 5, e16001 (2016).
[31] Eryürek, M., et al. Integrated humidity sensor based on SU-8 polymer microdisk microresonator. Sensors and Actuators B: Chemical 242, 1115-1120 (2017). doi: 10.1016/j.snb.2016.09.136
[32] Saetchnikov, A. V., et al. Reusable dispersed resonators-based biochemical sensor for parallel probing. IEEE Sensors Journal 19, 7644-7651 (2019). doi: 10.1109/JSEN.2019.2916861
[33] Lemieux-Leduc, C., et al. All-polymer whispering gallery mode resonators for gas sensing. Optics express 29, 8685-8697 (2021). doi: 10.1364/OE.417703
[34] Li ao, J. & Yang, L. Optical whispering-gallery mode barcodes for high-precision and wide-range temperature measurements. Light: Science & Applications 10, 32 (2021).
[35] Ta ng, S. J., et al. Single-particle photoacoustic vibrational spectroscopy using optical microresonators. Nature Photonics 17, 951-956 (2023). doi: 10.1038/s41566-023-01264-3
[36] Nishimura, J., et al. NaCl ion detection using a silica toroid microcavity. Applied optics 54, 6391-6396 (2015). doi: 10.1364/AO.54.006391
[37] Stoian, R. I., Lavine, B. K. & Rosenberger, A. T. pH sensing using whispering gallery modes of a silica hollow bottle resonator. Talanta 194, 585-590 (2019). doi: 10.1016/j.talanta.2018.10.077
[38] Loyez, M. et al. pH-sensitive optical micro-resonator based on PAA/PVA gel swelling. In Optics and Biophotonics in Low-Resource Settings IX, Vol. 12369, 1236907 (SPIE, 2023).
[39] L i, D. Y., et al. Monitoring the pH value of an aqueous micellar solution in real-time using a fiber optofluidic laser. Journal of Lightwave Technology 41, 362-366 (2023). doi: 10.1109/JLT.2022.3205885
[40] Bisswanger, H. Enzyme assays. Perspectives in Science 1, 41-55 (2014). doi: 10.1016/j.pisc.2014.02.005
[41] Kruse, P. Review on water quality sensors. Journal of Physics D: Applied Physics 51, 203002 (2018). doi: 10.1088/1361-6463/aabb93
[42] Mitchell, A., et al. Additive manufacturing — a review of 4D printing and future applications. Additive Manufacturing 24, 606-626 (2018). doi: 10.1016/j.addma.2018.10.038
[43] L ui, Y. S., et al. 4D printing and stimuli-responsive materials in biomedical aspects. Acta biomaterialia 92, 19-36 (2019). doi: 10.1016/j.actbio.2019.05.005
[44] Ovsianikov, A., Ostendorf, A. & Chichkov, B. N. Three-dimensional photofabrication with femtosecond lasers for applications in photonics and biomedicine. Applied Surface Science 253, 6599-6602 (2007). doi: 10.1016/j.apsusc.2007.01.058
[45] Saetchnikov, A. V., et al. A laser written 4D optical microcavity for advanced biochemical sensing in aqueous environment. Journal of Lightwave Technology 38, 2530-2538 (2020). doi: 10.1109/JLT.2020.2973933
[46] Saetchnikov, A. V., et al. Detection of per- and polyfluoroalkyl water contaminants with a multiplexed 4D microcavities sensor. Photonics Research 11, A88-A96 (2023). doi: 10.1364/PRJ.496737
[47] Huang, H. Q., et al. Four-dimensional printing of a fiber-tip multimaterial microcantilever as a magnetic field sensor. ACS Photonics 10, 1916-1924 (2023). doi: 10.1021/acsphotonics.3c00347
[48] Harris, D. C. Quantitative chemical analysis. 6th edn. (New York: W. H. Freeman and Company, 2003).
[49] Loock, H. P. & Wentzell, P. D. Detection limits of chemical sensors: Applications and misapplications. Sensors and Actuators B: Chemical 173, 157-163 (2012). doi: 10.1016/j.snb.2012.06.071
[50] Gorodetsky, M. L. & Fomin, A. E. Geometrical theory of whispering-gallery modes. IEEE Journal of Selected Topics in Quantum Electronics 12, 33-39 (2006). doi: 10.1109/JSTQE.2005.862954
[51] Ilchenko, V. S., et al. Whispering gallery mode diamond resonator. Optics Letters 38, 4320-4323 (2013). doi: 10.1364/OL.38.004320
[52] Sakellari, I., et al. Diffusion-assisted high-resolution direct femtosecond laser writing. ACS nano 6, 2302-2311 (2012). doi: 10.1021/nn204454c