Optofluidic laser has shown great potential in biochemical sensing. Here in this review, we systematically introduced the sensing mechanism and research progress of optofluidic laser based biochemical sensors. The gain medium regulated optofluidic laser sensing mainly depends on the quantity and state of gain molecules. When the biochemical reaction or molecules change the characteristics of microcavity, the resonance condition changes accordingly, and the change can be reflected and read out in the modes, wavelength and emission direction of lasing light. Furthermore, the biochemical molecules can introduce absorption loss and scattering loss in the laser cavity, causing measurable deterioration in laser intensity. Thanks to the amplification of lasing process and optical microcavity, and the narrow linewidth of laser, the laser output characteristics are ultrasensitive to the subtle changes of biochemical process to achieve high sensitivity and high-throughput biochemical sensing.
[1] Hansch T, Pernier M, Schawlow A. Laser action of dyes in gelatin[J]. IEEE Journal of Quantum Electronics, 1971, 7(1):45-46.
[2] Hansch T W. Edible lasers and other delights of the 1970s[J]. Optics & Photonics News, 2005, 16(2):14-16.
[3] Helbo B, Kristensen A, Menon A. A micro-cavity fluidic dye laser[J]. Journal of Micromechanics and Microengineering, 2003, 13(2):307.
[4] Shivakiran-Bhaktha B N, Bachelard N, Noblin X, et al. Optofluidic random laser[J]. Applied Physics Letters, 2012, 101(15):151101.
[5] Yu J, Liu Y, Wang Y, et al. Optofluidic laser based on a hollow-core negative-curvature fiber[J]. Nanophotonics, 2018, 7(7):1307-1315.
[6] Zhou T, Tang M, Xiang G, et al. Continuous-wave quantum dot photonic crystal lasers grown on on-axis Si (001)[J]. Nature Communications, 2020, 11(1):977.
[7] Moon H J, Chough Y T, An K. Cylindrical microcavity laser based on the evanescent wave coupled gain[J]. Physical Review Letters, 2000, 85(15):3161.
[8] Kazes M, Lewis D Y, Ebenstein Y, et al. Lasing from CdSe/ZnS quantum rods in a cylindrical microcavity[J]. Advanced Materials, 2002, 14(4):317-321.
[9] Schafer J, Mondia J P, Sharma R, et al. Quantum dot microdrop laser[J]. Nano Letters, 2008, 8(6):1709-1712.
[10] Gather M C, Yun S H. Lasing from Escherichia coli bacteria genetically programmed to express green fluorescent protein[J]. Optics Letters, 2011, 36(16):3299-3301.
[11] Lee W, Kim D B, Song M H, et al. Optofluidic ring resonator laser with an edible liquid laser gain medium[J]. Optics Express, 2017, 25(13):14043-14048.
[12] Maecel S, Lewis W, Isla R M B, et al, Monitoring contractility in cardiac tissue with cellular resolution using biointegrated microlasers[J]. Nature Photonics, 2020, 14:452-458.
[13] Malte C G, Seok H Y. Single-cell biological lasers[J]. Nature Photonics, 2011, 5:406-410.
[14] Matjaž H, Seok H Y. Intracellular microlasers[J]. Nature Photonics, 2015, 9:572-576.
[15] Nicola M, Sheldon J J K, Andreas C L, et al. Wavelength-encoded laser particles for massively multiplexed cell tagging[J]. Nature Photonics, 2019, 13:720-727.
[16] Wu X, Oo M K K, Reddy K, et al. Optofluidic laser for dual-mode sensitive biomolecular detection with a large dynamic range[J]. Nature Communications, 2014, 5:3779.
[17] Mao J G, Yang X, Liu Y L, et al. Nanomaterial-enhanced fiber optofluidic laser biosensor for sensitive enzyme detection[J]. Journal of Lightwave Technology, 2020, 38(18):5205-5211.
[18] Gong C Y, Gong Y, Oo M K K, et al. Sensitive sulfide ion detection by optofluidic catalytic laser using horseradish peroxidase (HRP) enzyme[J]. Biosensors and Bioelectronics, 2017, 96:351-357.
[19] Zhang X, Lee W, Fan X. Bio-switchable optofluidic lasers based on DNA Holliday junctions[J]. Lab on a Chip, 2012, 12(19):3673-3675.
[20] Wu J Y, Fan M W, Deng G W, et al. Optofluidic laser explosive sensor with ultralow detectionlimit and large dynamic range using donor-acceptor-donor organic dye[J]. Sensors Actuators B, 2019(298):126830.
[21] Lee W, Fan X D. Intracavity DNA melting analysis with optofluidic lasers[J]. Analytical Chemistry, 2012, 84(21):9558-9563.
[22] Tang S J, Liu Z, Qian Y J, et al. A tunable optofluidic microlaser in a photostable conjugated polymer[J]. Advanced Materials (Deerfield Beach, Fla), 2018, 30(50):e1804556.
[23] Yang X, Shu W, Wang Y, et al. Turbidimetric inhi-bition immunoassay revisited to enhance its sensitivity via an optofluidic laser[J]. Biosensors and Bioelectronics, 2019, 131(15):60-66.
[24] Rui D, Li Y Z, He Y C, et al. Quantitative and sensitive detection of lipase using liquid crystal microfiber biosensor based on whispering-gallery mode[J]. Analyst, 2020(145):7595-7602.
[25] Yang X, Luo Y, Liu Y, et al. Mass production of thin-walled hollow optical fiber enables disposable optofluidic laser immunosensor[J]. Lab on a Chip, 2020, 20(5):923-930.
[26] Gong C Y, Gong Y, Zhao X, et al. Distributed fibre optofluidic laser for chip-scale arrayed biochemical sensing[J]. Lab on a Chip, 2018, 18(18):2741-2748.
