基于纳米颗粒构建的酶联增敏生物传感器测定水中Cd^(2+)

Determination of Cd^(2+) in Water with Enzyme-Linked Sensitization Biosensor Based on Nanoparticles

以Fe3O4磁纳米颗粒和金纳米颗粒为载体,利用抗原-抗体的特异性识别作用,构建了乙酰胆碱酯酶(AChE)酶联增敏的生物传感器,并用于测定水中Cd^(2+)含量。对Fe3O4磁纳米颗粒进行镉-抗原功能化,对金纳米颗粒进行镉-抗体功能化和AChE修饰,功能化Fe3O4磁纳米颗粒和功能化并修饰了AChE的金纳米颗粒发生竞争性自组装形成组装体,组装体催化底物乙酰胆碱(ACh)水解产生乙酸进而引起反应体系的酸度变化,实现了Cd^(2+)的测定。Cd^(2+)的线性范围为0.001~10.0μg·L^(-1),检出限(3s/k)为0.24 ng·L^(-1)。在0.010,0.100,1.00μg·L^(-1)等3个浓度水平下进行加标回收试验,回收率为91.2%~107%,测定值的相对标准偏差(n=10)为3.5%~5.4%。

With Fe3O4 magnetic nanoparticlcs and gold nanoparticles as carricrs,acctylcholinesterase(AChE)-linked sensitization biosensor was constructed through the specific recognition of antigen-antibody to determine the content of Cd^(2+)in water.Fe3O4,magnetic nanoparticles were functionalized by Cd-antigen,and gold nanoparticles were functionalized by Cd-antibody and modified by AChE.The assembly was formed through competitive combination of functionalized Fe3O4 magnetic nanoparticles and functionalized and AChE modified gold nanoparticles.The assembly catalyzed the hydrolysis of substrate acetylcholine(ACh)to produce acetic acid,which changed the acidity of the reaction system and realized the determination of Cd^(2+).Linearity range of Cd^(2+)was found in the range of 0.001-10.0μg·L^(-1)with detection limit(3 s/k)of 0.24 ng·L^(-1).Tests for recovery were made by standard addition method at the concentration levels of 0.010,0.100,1.00μg·L^(-1),giving values of recovery and RSDs(n=10)in the ranges of 91.2%-107%and 3.5%-5.4%respectively.