Glucose sensors preparation

Figure 7. Amperometric response of glucose sensors prepared using LB film-coated electrodes. ( ) multilayer GOx (o) monolayer GOx sensors.

Yasuzawa, M., T. Matsuki, H. Mitsui, A. Kunugi, and T. Nakaya. 2000. Properties of glucose sensors prepared by the electropolymerization of pyrroles containing phosphatidylcholine (II). Sens Actuators B 66 25. 

The glucose sensor prepared by adsorption of GOD on a carbon electrode was mounted in a flow injection analysis system. It was found that the best signal-to-background and signal-to-noise ratios were obtained at around +800 mV on the rising part of the voltammetric wave. 

J. Pei and X. Li, Amperometric glucose enzyme sensor prepared by immobilizing glucose oxidase on CuPtC16 chemically modified electrode. Electroanalysis 11, 1266-1272 (1999). 

Zhao et al. prepared magnetite (FesO nanoparticles modified with electroactive Prussian Blue [44]. These modified NPs were drop-cast onto glassy-carbon electrodes. They observed the redox processes commonly observed for PB (similar to that seen in Figure 4.8), and also demonstrated that the Prussian White material produced by PB reduction at 0.2 V served as an electrocatalyst for Fi202 reduction. They also prepared LbL films in which PB NPs and glucose oxidase were alternated between PD DA layers [99]. These were demonstrated to act as electrocatalysts for Fi202 reduction. Based on the ability to sense the product of the enzymatic reaction, these structures were shown to act as glucose sensors. 

The LB film can be endowed with a variety of functions by being modified with functional molecules. We assembled a GOx monolayer on the surface of redox-active LB film composed of ferrocene-bearing amphiphile, according to the similar procedure as shown in Figure 6. The glucose sensor thus prepared showed an... 

Glucose sensors II and HI were prepared from the semipermeable membrane of PMSP, poly(1-trimethylsilyl-l-propyne), which has 4 times the oxygen permeability compared with that of FEP membrane. The response properties of sensor H, using a PMSP membrane with 25 Um diameter pinhole, were almost similer to that of the sensor I, so that their calibration curves were not presented in this paper. 

Yasuzawa M, Hashimoto M, Fujii S, Kunugi A, Nakaya T. Preparation of glucose sensors using the Langmuir-Blodgett technique. Sensors and Actuators B 2000, 65, 241-243. 

In order to maintain the advantage of the microfabrication approach which is intended for a reproducible production of multiple devices, parallel development of membrane deposition technology is of importance. Using modified on-wafer membrane deposition techniques and commercially available compounds an improvement of the membrane thickness control as well as the membrane adhesion can be achieved. This has been presented here for three electrochemical sensors - an enzymatic glucose electrode, an amperometric free chlorine sensor and a potentiometric Ca + sensitive device based on a membrane modified ISFET. Unfortunately, the on-wafer membrane deposition technique could not yet be applied in the preparation of the glucose sensors for in vivo applications, since this particular application requires relatively thick enzymatic membranes, whilst the lift-off technique is usable only for the patterning of relatively thin membranes. 

Wang, E, Amarasinghe, S., Leddy, I, Arnold, M., and Dordick, J. S. 1998. Enzymatically prepared poly(hydroquinone) as a mediator for amperometric glucose sensor. Polymer, 39,123-127. 

A layer-by-layer alternate electrostatic adsorption of monolayers of a positively-charged dendrimer (G4 poly(amidoamine)) and the negatively-charged protein glucose oxidase allows the preparation of multilayered assemblies for the construction of amperometric glucose sensors. This multilayer... 

Researchers turned their attention to applications of silica gel as a new electrode material. Silica gel, which has a three-dimensional structure with high specific surface area and is electroinactive in an aqueous medimn can be used as a support for electroactive species during their formation and/or enzymes by adsorption or entrapment [92,93]. Patel et al. recently reported application of poljwinyl ferrocene immobilized on silica gel particles to construct glucose sensors. Efficiency of carbon paste electrodes prepared with these polymeric electron mediators and GOx was comparable to electrodes constructed with other ferrocene based polymeric electron transfer systems. The fact that 70% of initial anodic current was retained after a month when electrodes were kept in the buffer at room temperature shows that polymerization of monomer vinylferrocene in the pores of silica gel and entrapping GOx in the matrix of poljwinyl ferrocene appears to have added stability to the sensors [94]. 

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