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Fabrication of Tyrosinase Biosensor Based on Multiwalled Carbon Nanotubes‐Chitosan Composite and Its Application to Rapid Determination of Coliforms
Author(s) -
Cheng Yuxiao,
Liu Yajun,
Huang Jingjing,
Xian Yuezhong,
Zhang Zhonghai,
Jin Litong
Publication year - 2008
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200704195
Subject(s) - biosensor , chitosan , detection limit , tyrosinase , nuclear chemistry , carbon nanotube , composite number , chemistry , electrode , materials science , chemical engineering , nanotechnology , chromatography , organic chemistry , composite material , enzyme , engineering
Abstract A tyrosinase (Tyr) biosensor was fabricated by immobilizing Tyr on the surface of multiwalled carbon nanotubes (MWNTs)‐chitosan (Chit) composite modified glassy carbon electrode (GCE). The MWNTs‐Chit composite film provided a biocompatible platform for the Tyr to retain the bioactivity and the MWNTs possessed excellent inherent conductivity to enhance the electron transfer rate. The Tyr/MWNTs‐Chit/GCE biosensor showed high sensitivity (412 mA/M), broad linear response (1.0×10 −8 –2.8×10 −5 M), low detection limit (5.0 nM) and good stability (remained 93% after 10 days) for determination of phenol. The biosensor was further applied to rapid detection of the coliforms, represented by Escherichia coli ( E. coli ) in this work. The current responses were proportional to the quantity of coliforms in the range of 10 4 –10 6 cfu/mL. After 5.0 h of incubation, E. coli could be detected as low as 10 cfu/mL.