MRS Proceedings


Label-free Electrochemical Biosensor Based on Graphene/Ionic Liquid Nanocomposite for the Detection of Organophosphate Pesticides

2010 MRS Fall Meeting.

Tae Jung Parka1, MinHo Yanga2, Bong Gill Choia2, Nam Su Heoa1, Seok Jae Leea3, Won Hi Honga2 and Sang Yup Leea1a2a4

a1 BioProcess Engineering Research Center, Center for Systems & Synthetic Biotechnology, and Institute for the BioCentury, KAIST, Daejeon 305-701, Republic of Korea

a2 Department of Chemical & Biomolecular Engineering (BK21 program), KAIST, Daejeon 305-701, Republic of Korea

a3 NTD&I Team, National Nanofab Center, Daejeon 305-806, Republic of Korea

a4 Department of Bio & Brain Engineering, Department of Biological Sciences, and Bioinformatics Research Center, KAIST, Daejeon 305-701, Republic of Korea


The advanced electrodes for detecting organophosphate pesticides were prepared by modification of the gold (Au) electrode with the reduced graphene oxide/ionic liquid (RGO/IL) nanohybrids. Due to the cationic and anionic parts, the ILs on RGO sheets provide the amount of functional groups for dispersion of hybrids and immobilization of organophosphorus hydrolase (OPH) enzymes. After the immobilization of OPH on the RGO/IL-modified Au electrodes, the modified electrodes represent faster electron transfer than that of Au electrode, resulting in high performance of biosensor with response time (~ 10 s) and sensitivity (4.56 nA μM−1). In addition, the OPH/RGO/IL-modified Au electrode displayed good stability and reproducibility.

(Online publication March 07 2011)

Key Words:

  • electrical properties;
  • sol-gel;
  • sensor