Yao and Shiu constructed a mediator type glucose sensor based on the immobilization of GOx at electropolymerized poly film on CNTs modified GCE. Poly provided the polymer matrices to maintain the sensing activity and served as a redox mediator for enzymatic glucose oxidation. This biosensor showed enhanced current response at low potential and therefore common interferences from AA, UA, and acetaminophen could be avoided. Zhu and coworkers IC-87114 suggested a Prussian Blue based amperometric glucose biosensor by assembling the PB nanoparticles on the surface of MWCNTs modified GCE followed by immobilization of GOx. It showed good sensitivity, fast response with a detection limit of 12.7 mM. Similar PB based glucose biosensors were also prepared by immobilizing GOx in a film of LBL assembly of CS and MWCNTs and on the nanocomposite film of PB nanoparticles/MWCNTs/poly. Manesh et al.
fabricated a glucose biosensor based on the immobilization of GOx into an electrospun composite membrane consisting of polymethylmethacrylate dispersed with MWCNTs wrapped by a cationic PDDA polymer. This nanofibrous electrode exhibited excellent electrocatalytic activity towards H2O2 with a pronounced oxidation current at 100 mV. Glucose was detected amperometrically BMY 7378 with this nanofibrous electrode with a detection limit of 1 M. A highly sensitive and selective glucose biosensor based on immobilization of GOx within mesoporous CNTstitania Nafion composite film coated on a platinized GCE, was also developed recently by Lee and coworkers. It responded linearly to glucose in the wide range from 50 ?M to 5.0 mM with sensitivity of 154 mA M 1cm 2.
A mediatorless glucose biosensor, based on the incorporation of GOx to the composite electrode of colloidal gold CNTs Teflon showed a remarkably higher sensitivity than that achieved with other GOx CNTs bioelectrodes. It could be used for ethanol biosensor by incorporating alcohol dehydrogenase. Chu et al. developed an amperometric glucose biosensor based on adsorption of GOx at the gold and platinum nanoparticles modified CNTs electrode where CNTs were covalently immobilized on cysteamine modified gold electrode. The GOx/Au nano/Pt nano/CNTs/Au electrode was then covered with a thin layer of Nafion to avoid the loss of GOx and suppress the interfering signals from UA and AA. Recently, Zou et al. developed an amperometric glucose biosensor based on electrodeposition of platinum nanoparticles onto MWCNTs and entrapping an enzyme in CS SiO2 sol gel.
This electrode showed an excellent electrocatalytic activity and high stability as well due to the synergistic action of Pt and MWCNTs and the biocompatibility of CS SiO2 sol gel. A wide linear range from 1 M to 23 mM and a low detection limit of 1 M was achieved for glucose sensing. Zhao et al. recently investigated an amperometric glucose biosensor based on PtNPs combined aligned CNTs electrode. The combination of PtNPs and CNTs in this glucose biosensor showed a highly sensitive detection of glucose. Kang et al. constructed another glucose biosensor based on the integration of CNTs with gold platinum alloy nanoparticles. In this sensor, GOx was immobilized in biocompatible CS through cross linking with GA on the Au PtNPs/CNTs/CS film.