Properties of glucose biosensors based on dendrimer layers. Effect of enzyme immobilization

Abstract

The properties of glucose biosensors based on dendrimer layers on a gold support, which depend on the method of immobilization of glucose oxidase (GOX), were studied by amperometry. The kinetic parameters of enzymatic reactions, response time, sensitivity, detection limit, linear range, and enzyme turnover were determined. We showed that a more stable and sensitive sensor was obtained when GOX was immobilized on the dendrimer by crosslinking with glutaraldehyde in vacuum. This biosensor was stable for at least eight weeks. The response time was approximately 1.3 min, the detection limit of glucose was 25 micro M, and the apparent Michaelis-Menten constant was relative low ( K(m)=1.1+/-0.1 mM) in comparison with that for GOX in solution. The reason for these differences is discussed. The example of the application of the developed biosensors for the detection of mercury is also presented. The inhibitory effect of mercury on GOX activity was observed at mercury concentration of 100 nM.

PAMAM Dendrimers‐Based DNA Biosensors for Electrochemical Detection of DNA Hybridization

“…There are also some works reporting that PAMAM dendrimers form self-assembled monolayers (SAM) on a gold support for development biosensors [36 -38]. Hianik reported the suitability of the polyamidoamine (PAMAM) dendrimer G1 for the development of the glucose biosensor [36]. G1 was adsorbed on a gold support together with hexadecanethiol, and the properties of the sensor depending on the method of immobilization of GOX -by crosslinking with glutaraldehyde were studied.…”

Preparation of a Cellulose-based Enzyme Membrane Using Ionic Liquid to Lengthen the Duration of Enzyme Stability

“…[6][7][8] Mainly, the methods are divided into 2 categories: covalent bonding and entrapping. While the possibility of loss of the immobilized enzyme exists, through leakage or dissolution, it is small for immobilization achieved by covalent bonding [9][10][11] and cross-linking, [12][13][14][15][16][17][18][19][20] and there remains fear of enzyme activity loss due to reagents used in the bonding reaction; there are means for prolonging the duration of enzyme stability, but the enzyme may be damaged during such immobilization processes.…”

The 2.1 Å structure ofAerococcus viridansL-lactate oxidase (LOX)

“…The FAD-dependent glucose and cholesterol oxidases are also used in biosensors (Sarath Babu et al, 2004;Svobodova et al, 2002;Pan et al, 2003). The current l-lactate oxidase (LOX) from Aerococcus viridans is used as the receptor in biosensor applications developed to determine blood lactate levels (Gavalas & Chaniotakis, 2001;Ito et al, 1996;Poscia et al, 2005).…”