[1] R. Bellanti, S. Keddie, M. Lunn et al. Ultrasensitive assay technology and fluid biomarkers for the evaluation of peripheral nerve disease. J. Neurol. Neurosurg. Psych., 95, 114(2023).

[2] J. Chen, J. Zhao, J. Feng et al. Photoelectrochemical immunosensor based on a 1D Fe2O3/3D Cd-ZnIn2.2Sy heterostructure as a sensing platform for ultrasensitive detection of neuron-specific enolase. Anal. Chem., 94, 17396(2022).

[3] Q. Wang, P. Liu, Q. He et al. Characteristics comparison of photoacoustic signal of glucose solution in time domain and frequency domain. Opt. Precision Eng., 28, 2421(2020).

[4] M. K. E. Annika, G. S. Thomas, O. Jeankun et al. Raman spectroscopy for noninvasive glucose measurements. J. Biomed Opt., 10, 031114(2005).

[5] R. Falciai, A. G. Mignani, A. Vannini. Long period gratings as solution concentration sensors. Sens. Actuators B, 74, 74(2001).

[6] J. Rao, R. Yang, H. Yuan et al. Ultrasensitive trace detection of dye molecules based on scanning microsphere-coupled surface-enhanced Raman spectroscopy. J. Phys. Chem. C, 128, 8418(2024).

[7] D. Traversi, S. Villa, E. Lorenzi et al. Application of a real-time qPCR method to measure the methanogen concentration during anaerobic digestion as an indicator of biogas production capacity. J. Environ. Manage., 111, 173(2012).

[8] R. de la Rica, M. M. Stevens. Plasmonic ELISA for the detection of analytes at ultralow concentrations with the naked eye. Nat. Protoc., 8, 1759(2013).

[9] F. Akhter, H. R. Siddiquei, M. E. E. Alahi et al. Recent advancement of the sensors for monitoring the water quality parameters in smart fisheries farming. Computers, 10, 26(2021).

[10] X. Yang, H. Wang, H. Liu et al. Fully integrated sensor array for additives, permittivity, and pH monitoring for fishery. J. Hazard. Mater., 479, 135660(2024).

[11] A. I. Zia, A. R. M. Syaifudin, S. C. Mukhopadhyay et al. Electrochemical impedance spectroscopy based MEMS sensors for phthalates detection in water and juices. J. Phys., 439, 012026(2013).

[12] J. Hu, C.-H. T. Yew, X. Chen et al. Paper-based capacitive sensors for identification and quantification of chemicals at the point of care. Talanta, 165, 419(2017).

[13] Y. Su, S. Yang, W. Liu et al. Visible light photoelectrochemical sulfide sensor based the use of TiO2 nanotube arrays loaded with Cu2O. Microchim. Acta, 184, 4065(2017).

[14] H. Zhang, F. Liang, S. Li et al. A high-performance photoelectrochemical sensor based on CdS–Au composite nanomaterials and localized surface plasmon resonance for ultrasensitive detection of ascorbic acid. Anal. Methods, 16, 1175(2024).

[15] D. Qi, A. J. Berger. Chemical concentration measurement in blood serum and urine samples using liquid-core optical fiber Raman spectroscopy. Appl. Opt., 46, 1726(2007).

[16] Y. Zhao, Z.-Q. Deng, Q. Wang. Fiber optic SPR sensor for liquid concentration measurement. Sensors Actuators B: Chem., 192, 229(2014).

[17] B. Han, Y. Ma, H. Wu et al. Random Raman Fiber Laser as a Liquid Refractive Index Sensor. Photon. Sensors, 14, 240121(2023).

[18] Y. Lu, H. Li, X. Qian et al. Beta-cyclodextrin based reflective fiber-optic SPR sensor for highly-sensitive detection of cholesterol concentration. Opt. Fiber Technol., 56, 102187(2020).

[19] W. Zheng, B. Han, Y.-N. Zhang et al. An in-fiber sensor for simultaneous measurement of cholesterol concentration and temperature based on SPR and MMI. Anal. Chim. Acta, 1287, 342043(2024).

[20] X. Wu, S. Si, W. Tan et al. Preparation of magnetic mesoporous metal-phenolic coordination spheres for extraction of crystal violet and leuco-metabolites in fish. J. Chromatogr. A, 1636, 461776(2021).

[21] R. B. Inamuddin, G. Kaur, A. M. Asiri, H. Singh, J. Singh. Chapter 2 - UV-vis spectrophotometry for environmental and industrial analysis. Green Sustainable Process for Chemical and Environmental Engineering and Science, 49(2021).

[22] D. Jinru, F. Zilin, S. Xueyi et al. Detection of crystal violet in environmental water by a handheld Raman spectrometer combined with bimetallic Au@AgNPs aggregates. Chin. J. Anal. Lab., 43, 364(2024).

[23] S. Zhao, W. Tao, Q. He et al. A non-invasive photoacoustic and ultrasonic method for the measurement of glucose solution concentration. AIP Adv., 7, 035313(2017).

[24] D. Samanta, P. Narumbam, A. Paramanick et al. Quantitative photoacoustic microscopy for methylene blue concentration mapping in agar phantoms at multiple wavelengths. BiOS(2024).

[25] S.-J. Tang, S. Liu, X.-C. Yu et al. On-chip spiral waveguides for ultrasensitive and rapid detection of nanoscale objects. Adv. Mater., 30, 1800262(2018).

[26] X.-C. Yu, S.-J. Tang, W. Liu et al. Single-molecule optofluidic microsensor with interface whispering gallery modes. Proc. Natl. Acad. Sci., 119, e2108678119(2022).

[27] S. Tang, M. Zhang, S. Jialve et al. Single-particle photoacoustic vibrational spectroscopy using optical microresonators. Nat. Photonics, 17, 951(2023).

[28] F. H. Tian, Y. M. Liu, R. L. Ma et al. Properties of PMN-PT single crystal piezoelectric material and its application in underwater acoustic transducer. Appl. Acoust., 175, 107827(2021).

[29] S. J. Z. Wong, K. Roy, C. Lee et al. Thin-film piezoelectric micromachined ultrasound transducers in biomedical applications: a review. IEEE Trans. Ultrasonics Ferroelectrics Freq. Control, 71, 622(2024).

[30] A. Paramanick, K. Roy, S. Paul et al. Photoacoustic imaging with single-element, low-frequency thin-film PMUT. IEEE Sensors Lett., 8, 6002304(2024).

[31] K. Roy, K. Kalyan, A. Ashok et al. A PMUT integrated microfluidic system for fluid density sensing. J. Microelectromech. Syst., 30, 642(2021).

[32] R. Kaustav, S. Vijayendra, K. Akshay et al. A PMUT based photoacoustic system as a microfluidic concentration detector. Proc. SPIE, 119603, 1196013(2022).

[33] K. Roy, A. Thomas, S. Paul et al. An optofluidic dye concentration detector based on the pulsed photoacoustic effect. BiOS(2021).

[34] C. Zhang, T. Ling, S. Chen et al. Ultrabroad bandwidth and highly sensitive optical ultrasonic detector for photoacoustic imaging. ACS Photonics, 1, 1093(2014).

[35] J. Sun, S. Tang, J. Meng et al. Whispering-gallery optical microprobe for photoacoustic imaging. Photonics Res., 11, A65(2023).

[36] Z. Ding, J. Sun, C. Li et al. Broadband Ultrasound Detection Using Silicon Micro-Ring Resonators. J. Lightwave Technol., 41, 1906(2023).

[37] R. Docampo, S. N. Moreno. The metabolism and mode of action of gentian violet. Drug Metab. Rev., 22, 161(1990).

[38] A. Mittal. Adsorption kinetics of removal of a toxic dye, Malachite Green, from wastewater by using hen feathers. J. Hazard. Mater., 133, 196(2006).

[39] I. A. Rahman, B. Saad, S. Shaidan et al. Adsorption characteristics of malachite green on activated carbon derived from rice husks produced by chemical–thermal process. Bioresour. Technol., 96, 1578(2005).

[40] S. J. Culp, L. R. Blankenship, D. F. Kusewitt et al. Toxicity and metabolism of malachite green and leucomalachite green during short-term feeding to Fischer 344 rats and B6C3F1 mice. Chem. Biol. Interact., 122, 153(1999).

[41] S. J. Culp, P. W. Mellick, R. W. Trotter et al. Carcinogenicity of malachite green chloride and leucomalachite green in B6C3F1 mice and F344 rats. Food Chem. Toxicol., 44, 1204(2006).

[42] T. Schmid, U. Panne, R. Niessner et al. Optical absorbance measurements of opaque liquids by pulsed laser photoacoustic spectroscopy. Anal. Chem., 81, 2403(2009).

[43] N. Sanjarani, M. Rahmani. Exploration of supramolecular solvent-based microextraction for crystal violet detecting in water samples. Heliyon, 10, e38884(2024).

[44] D. Xu, Y. Zhang, S. Zhang et al. Ultrasensitive SERS detection of crystal violet and malachite green based on high surface roughness copper nanocorns prepared via solid-state ionics method. Sens. Actuators A, 331, 113042(2021).

[45] L. Dai, C. Su, Y. Ma et al. Measurement of methylene blue concentration in water by LPFG based on surface modification of calcium alginate hydrogel. Measurement, 251, 117351(2025).

[46] A. Perez, F. Del, C. Ortegón et al. Analysis of photoacoustic signals of crystal violet dye solutions. Colloquium Spectroscopicum Internationale XLI(2019).