Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication and Application to Sensing the Extracellular H₂O₂ Released from Cells

Authors

Ping WU, Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China;
Chen-xin CAI, Jiangsu Key Laboratory of New Power Batteries, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210046, China;Follow

Corresponding Author

Chen-xin CAI(cxcai@njnu.edu.cn)

Abstract

The nanostructured attapulgite clay was employed as a support matrix for immobilizing horseradish peroxidase (HRP). FTIR and electrochemical methods demonstrated that HRP had been effectively assembled on attapulgite surface with the formation of HRP-attapulgite nanocomposites. The HRP-attapulgite hybrid was deposited on the glassy carbon (GC) electrode forming the HRP-attapulgite/GC electrode. Cyclic voltammetric results showed a pair of well-defined redox peaks, which were ascribed to direct electron transfer (DET) of HRP, with the formal potential E₀′ = -335 mV (vs. SCE) in the phosphate buffer solution (PBS, pH 7.0). The dependence of E₀′ on solution pH indicated that DET reaction of HRP was coupled with proton transfer. The developed electrode revealed a good electrocatalytical activity toward the reduction of H₂O₂. The electrocatalyic current was linear to the concentration of H₂O₂ in the concentration range of 0.3 to 75 μmol·L^-1 with high sensitivity ((53 ± 2) μA·(mmol·L^-1)^-1·cm^-2) and low detection limit ((0.10 ± 0.05) μmol·L^-1). Moreover, the HRP-attapulgite/GC electrode was used to detect the level cellular H₂O₂ released from the Macrophages cells (RAW 264.7). Therefore, an electrochemical approach for detection of cellular H₂O₂ based on HRP-attapulgite hybrid was developed. This study has not only established a novel approach to detect cellular H₂O₂, but also provided a general route for fabricating attapulgite-based biosensing platform via assembling enzymes/proteins on attapulgite surface, expanded the scope of attapulgite applications to the field of bioelectroanalytical chemistry and cellular biology.

Graphical Abstract

Keywords

horseradish peroxidase, attapulgite, hydrogen peroxide, macrophages cell

DOI Link

https://doi.org/10.13208/j.electrochem.130883

Publication Date

2014-06-28

Online Available Date

2013-09-30

Revised Date

2013-09-23

Received Date

2013-08-26

Recommended Citation

Ping WU, Chen-xin CAI. Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication and Application to Sensing the Extracellular H₂O₂ Released from Cells[J]. Journal of Electrochemistry, 2014 , 20(3): 260-265.
DOI: 10.13208/j.electrochem.130883
Available at: https://jelectrochem.xmu.edu.cn/journal/vol20/iss3/7