Interferents, biosensors

J. Tkac, E. Sturdik and P. Gemeiner, Novel glucose non-interference biosensor for lactose detection based on galactose oxidase-peroxidase with and without co-immobilised beta-galactosidase, Analyst, 125(7) (2000) 1285-1289. 

Jung, S.K., and Wilson, G.S. (1996) Polymeric mercaptosilane-modified platinum electrodes for elimination of interferants in glucose biosensors. Anal Chem. 68(4), 591-596. 

S. Sasso, R. Pierce, R. Walla, and A. Yacynych, Electropolymerized 1,2-diaminobenzene as a means to prevent interferences and fouling and to stabilize immobilized enzyme in electrochemical biosensors. Anal. Chem. 62, 1111-1117 (1990). 

Current responses of the biosensor toward 02 and potential interferents... 

UA, AA, and DOPAC, with the concentrations approximating their extracellular fluid levels were investigated at +300 and -lOOmV at the SOD-based biosensors at +300mV, the interferences from AA and UA were considerable, for instance 15% and 23% current responses were obtained for 500 pM AA relative to 13 nM 02 with Fe-SOD/MPA-modified and Mn-SOD/MPA-modified Au electrodes, respectively. In addition, 10% current response was obtained for 50 pM UA relative to 13 nM 02 at both electrodes. Fortunately, such interferences were well suppressed when the electrodes were polarized at -lOOmV. Besides, the interferences of H202, 5-HIAA, HVA, and DOPAC were negligible at both +300 and -lOOmV at both electrodes [138],... 

The interference from 02 was also investigated with the SOD-based biosensors, in which 02 was generated from K02 rather than from the xanthine-XOD system since the enzymatic system requires 02 for the 02, generation. The removal of 02 from the phosphate buffer by bubbling N2 into the solution was found to produce no observable change in the current response of the SOD-based biosensors toward K02, suggesting that 02 does not interfere with 02, determination under the present experimental conditions. 

Among different approaches providing operation of the oxidase-based biosensors, the detection of hydrogen peroxide production was found to be the most progressive one, allowing detection of low levels of analytes [107], However, the detection of H202 has to be carried out at low potentials in order to reduce the interference of easily oxi-dizable compounds [110]. 

C.R. Yonzon, C.L. Haynes, X. Zhang, J.T. Walsh Jr. and R.P. Van Duyne, A glucose biosensor based on surface-enhanced Raman scattering improved partition layer, temporal stability, reversibility, and resistance to serum protein interference, Anal. Chem., 76(1) (2004) 78-85. 

Biosensors fabricated on the Nafion and polyion-modified palladium strips are reported by C.-J. Yuan [193], They found that Nafion membrane is capable of eliminating the electrochemical interferences of oxidative species (ascorbic acid and uric acid) on the enzyme electrode. Furthermore, it can restricting the oxidized anionic interferent to adhere on its surface, thereby the fouling of the electrode was avoided. Notably, the stability of the proposed PVA-SbQ/GOD planar electrode is superior to the most commercially available membrane-covered electrodes which have a use life of about ten days only. Compared to the conventional three-dimensional electrodes the proposed planar electrode exhibits a similar... 

Attempts to reduce interference and minimize the effect of variations in oxygen tension have resulted in the development of biosensors with improved linear ranges which operate at lower electrode potentials. They incorporate artificial electron acceptors, called mediators, to transfer electrons from the flavoenzyme (e.g. glucose oxidase) to the electrode and thus are not dependent on oxygen. Ferrocene (bis(i75-cyclopentadienyl)iron) and its derivatives are examples of redox mediators for flavoenzymes. The reaction now becomes... 

On the other hand, limited advances have been made with regard to the development of biosensors toward the detection of this group of compounds. Marchesini et al. [92], reported on an SPR biosensor based on the thyroxine (T4) transport disrupting activity to screen chemicals (including PBDEs) that may interfere with the thyroid system [92]. 

Schmid et al. used the same principle to develop sensors to be incorporated into FI systems for the determination of ascorbic acid in fruit juices [38] and that of lactic acid in dairy products [39]. The membrane used in both applications consisted of decacyclene dissolved in silicone rubber that was treated similarly as the membrane in glucose sensors (Fig. 3.4.B). The oxygen optrode was coated with a sheet of carbon black as optical insulation in order to protect it from ambient light or intrinsic sample fluorescence. Ascorbic acid oxidase or lactic acid oxidase was immobilized by adsorbing it onto carbon black and cross-linking it with glutaraldehyde. The FI system automatically buffered and diluted the food samples, thereby protecting the biosensor from a low pH and interferents. 

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