选择性测量H_(2)O_(2)浓度的光纤倏逝波生物传感器

Fiber-Optic Evanescent Wave Biosensor for Selective Detection of H_(2)O_(2) Concentration

为了实现对H_(2)O_(2)浓度选择性、准确的检测,研制了一种基于辣根过氧化物酶(HRP)的光纤倏逝波生物传感器。首先采用氢氧化钠溶液对去除部分纤芯的抗紫外石英光纤进行羟基化,接着利用3-氨基丙基三乙氧基硅烷进行硅烷化,其次将光纤浸入戊二醛溶液中进行醛基交联,再次将光纤移入对H_(2)O_(2)具有选择催化性的HRP溶液中进行HRP分子固定,最后将固定有HRP的光纤在室温下晾干,即可获得HRP固定化光纤生物传感器。实验研究了戊二醛、HRP的浓度和固定时间、H_(2)O_(2)溶液的温度对传感器灵敏度的影响,测试了传感器的响应时间、选择敏感性及检测下限,建立了传感器的理论模型。研究结果表明,传感器对H_(2)O_(2)有高选择敏感性,在4~20μmol·L^(-1)的H_(2)O_(2)浓度范围内传感器的输出信号与浓度间具有线性关系,灵敏度达到-8.164×10^(-4)μmol^(-1)·L,相对误差为7.59%,检测下限达到4μmol·L^(-1)。

In order to realize the selective and accurate detection of H_(2)O_(2) concentration,a fiber-optic evanescent wave biosensor based on horseradish peroxidase(HRP)is developed.First,the ultraviolet resistant quartz fiber with partial core removal is hydroxylated with sodium hydroxide solution and silanized with 3-aminopropyl triethoxysilane,then the fiber is immersed in glutaraldehyde solution for aldehyde cross-linked,and the fiber is moved into HRP solution with selective catalysis for H_(2)O_(2) to fix HRP molecules.Finally,the fiber with HRP is dried at room temperature.The optical fiber biosensor immobilized on HRP can be obtained.The effects of the concentration and fixed time of glutaraldehyde and HRP and the temperature of H_(2)O_(2) solution on the sensitivity of the sensor are studied experimentally.The response time,selection sensitivity,and detection limit of the sensor are tested,and the theoretical model of the sensor is established.The results show that the sensor has a high selective sensitivity to H_(2)O_(2),and the output signal of the sensor has a linear relationship with the concentration of H_(2)O_(2) in the range of 4--20μmol·L^(-1),the sensitivity is-8.164×10^(-4)μmol^(-1)·L,the relative error is 7.59%,and the detection limit is 4μmol·L^(-1).