Enzyme functionalized nanoparticles for electrochemical biosensors: a comparative study with applications for the detection of bisphenol A.

We developed electrochemical biosensors based on enzyme functionalized nanoparticles of different compositions for the detection of bisphenol A. We utilized for the first time magnetic nickel nanoparticles as an enzyme immobilization platform and electrode material to construct screen-printing enzyme biosensors for bisphenol A. We compared the analytical performance of these sensors with those based on iron oxide (Fe(3)O(4)) and gold nanoparticles. The proposed biosensor format exhibited fast and sensitive amperometric responses to bisphenol A with a response time of less then 30s. Among the three configurations, nickel provided comparable or better characteristics in terms of detection limit and sensitivity than Fe(3)O(4) and gold nanoparticles. The biosensors were characterized by good reproducibility, stability of more than 100 assays (residual activity for nickel was 98%) and a wide linear range which spanned from 9.1 × 10(-7) to 4.8 × 10(-5)M for nickel, 2.2 × 10(-8) to 4.0 × 10(-5)M for Fe(3)O(4) and 4.2 × 10(-8) to 3.6 × 10(-5)M for gold. The highest sensitivity was obtained with nickel. The detection limits for the three types of biosensors were: 7.1 × 10(-9), 8.3 × 10(-9) and 1 × 10(-8)M for nickel, Fe(3)O(4) and gold nanoparticles in that order, respectively. These results demonstrate that nickel nanoparticles can be successfully used in the construction of electrochemical enzyme sensors for the detection of phenolic compounds. Copyright 2010 Elsevier B.V. All rights reserved.