Multiplexed optical fiber cell temperature sensing system with high sensitivity and accuracy

Yu Guo; Yanxia Shen; Xinyu Sun; Shulin Song; Haodong Wu; Xiulan Sun

doi:10.1117/1.JBO.28.4.047001

Multiplexed optical fiber cell temperature sensing system with high sensitivity and accuracy

J Biomed Opt. 2023 Apr;28(4):047001. doi: 10.1117/1.JBO.28.4.047001. Epub 2023 Apr 8.

Authors

Yu Guo^{1

2}, Yanxia Shen¹, Xinyu Sun², Shulin Song¹, Haodong Wu³, Xiulan Sun²

Affiliations

¹ Jiangnan University, School of Internet of Things Engineering, Wuxi, China.
² Jiangnan University, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, State Key Laboratory of Food Science and Technology, Wuxi, China.
³ Nanjing University, School of Physics, Nanjing, China.

Abstract

Significance: A multiplexed fiber laser sensing system for cell temperature is proposed. To the best of the authors' knowledge, this is the first multilongitudinal mode (MLM) optical fiber laser sensor array designed for cell temperature sensing.

Aim: A two-channel cell temperature sensing system with high sensitivity and real-time sensing capability is achieved. The temperature change of human hepatoellular carcinomas (HepG2) cells under the influence of exogenous chemical aflatoxin B1 (AFB1) can be monitored in real time.

Approach: A fiber laser cavity consists of a pair of fiber Bragg gratings (FBGs) with matched central wavelengths and a piece of erbium-doped fiber (EDF). The static FBG is utilized for design of fiber laser cavity and laser modes selection. In comparison, the sensing FBG is used for cell temperature sensing. The sensing FBG has a length of 10 mm and a diameter of $200 μ m$ . Beat frequency signals (BFS) are generated by MLM lasers after optical-to-electrical conversion at a photodetector. Frequency change of a BFS is closely related to the reflected wavelength change of the sensing FBG. Through frequency division multiplexing, two fiber laser cavities are designed in the sensing system for two-channel temperature sensing. Frequency shift of a BFS that represents temperature change of cells can be automatically recorded in seconds.

Results: A two-channel cell temperature sensing system is designed with high sensitivities of 101.62 and $119.82 kHz / ° C$ , respectively. The temperature change of HepG2 cells under the influence of exogenous chemical AFB1 is monitored in real time.

Conclusions: The proposed system has the advantages of simple structure, high sensitivity, and two-channel sensing capability. Our study provides a simple and effective method to design a fiber laser sensor system without complex demodulation techniques and expensive optical components.

Keywords: beat frequency signal; fiber Bragg grating; optical fiber sensing system; two-channel cell temperature sensing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Equipment Design
Fiber Optic Technology*
Humans
Optical Fibers*
Refractometry
Temperature