Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

Sensors

Kee-Shyuan Loh¹  Yook Heng Lee¹  Ahmad Musa¹  Abdul Aziz Salmah² 

[1] School of Chemical Sciences and Food Technology, Faculty of Science and Technology, University Kebangsaan Malaysia, Bangi, 43000, Selangor, Malaysia; E-mails:;Biotechnology Research Centre, Malaysian Agriculture Research & Development Institute (MARDI), P.O. BOX 12301, GPO Kuala Lumpur, Malaysia; E-mails:

关键词: Screen-printer biosensor;    alkaline phosphatase;    Fe₃O₄ nanoparticles;    2;    4-dichlorophenoxyacetic acid;   

DOI  :  10.3390/s8095775

来源: mdpi

【 摘 要 】

Magnetic nanoparticles of Fe₃O₄ were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe₃O₄ nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe₃O₄ nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P). The incorporation of the Fe₃O₄ nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM) and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The use of Fe₃O₄ nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL^-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg²⁺, Cu²⁺, Ag²⁺ and Pb²⁺. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method.

【 授权许可】

CC BY   
© 2008 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.