Opt Express. 2021 Nov 8;29(23):38150-38167. doi: 10.1364/OE.445555.
The purpose of this work is to propose a simple, portable, and sensitive biosensor structure based on singlemode fiber-multicore fiber-multimode fiber-singlemode fiber (SMF-MCF-MMF-SMF) for the detection of creatinine in the human body. Chemical etching has been used to modify the diameter of the sensing probe to approximately 90 μm in order to generate strong evanescent waves (EWs). The sensor probe is functionalized with graphene oxide (GO), gold nanoparticles (AuNPs), molybdenum disulfide nanoparticles (MoS-NPs), and creatininase (CA) enzyme. The concentration of creatinine is determined using fiber optic localized surface plasmon resonance (LSPR). While EWs are used to enhance the LSPR effect of AuNPs, two-dimensional (2D) materials (GO and MoS-NPs) are used to increase biocompatibility, and CA is used to increase probe specificity. Additionally, HR-TEM and UV-visible spectroscopy are used to characterize and measure the nanoparticle (NP) morphology and absorption spectrum, respectively. SEM is used to characterize the NPs immobilized on the surface of the fiber probe. The sensor probe's reusability, reproducibility, stability, selectivity, and pH test results are also tested to verify the sensor performance. The sensitivity of proposed sensor is 0.0025 nm/μM, has a standard deviation of 0.107, and has a limit of detection of 128.4 μM over a linear detection range of 0 - 2000 μM.
本工作旨在提出一种基于单模光纤-多模光纤-多模光纤-单模光纤（SMF-MCF-MMF-SMF）的简单、便携、灵敏的生物传感器结构，用于检测人体中的肌酐。化学刻蚀用于修饰传感探头的直径，使其大约为 90μm，以产生强倏逝波（EWs）。传感器探头功能化有氧化石墨烯（GO）、金纳米粒子（AuNPs）、二硫化钼纳米粒子（MoS-NPs）和肌氨酸氧化酶（CA）酶。通过光纤局域表面等离子体共振（LSPR）来确定肌酐的浓度。EWs 用于增强 AuNPs 的 LSPR 效应，二维（2D）材料（GO 和 MoS-NPs）用于提高生物相容性，CA 用于提高探针的特异性。此外，高分辨透射电子显微镜（HR-TEM）和紫外-可见分光光度计分别用于纳米粒子（NP）的形态和吸收光谱的表征和测量。扫描电子显微镜（SEM）用于表征纤维探针表面固定的 NPs。还测试了传感器探头的可重复性、重现性、稳定性、选择性和 pH 值测试结果，以验证传感器性能。所提出的传感器的灵敏度为 0.0025nm/μM，标准偏差为 0.107，线性检测范围为 0-2000μM 时，检测限为 128.4μM。
