Reagentless Biosensor Architectures

Designing appropriate and efficient ET pathways within a biosensor intrinsically requires that the generated environment is suitable for the chosen biological recognihon element. Its catalyhc achvity and stability might be tuned to the desired performance by the immobilization matrix. The immobilization procedure itself needs to be compahble with the ET pathway strategy. For instance, the stress on 

Eor instance, if one would like to design a suitable redox polymer for a certain enzymatic reaction, it helps to think about the following factors. Eirst, the redox polymer needs to create a three-dimensional network that allows secure immobilization of the enzyme with a reasonable pore size. In addition, fast diffusion of the analyte, products, or counter-ions and fast ET kinehcs need to be ensured. The polymer film deposited as sensing layer creates a diffusion barrier which often prolongs the response time, shifts the linear measuring range, and decreases the sensitivity of the sensor. Second, the redox polymer should create a local 

The general advantages of reagentless biosensor structures can be summarized as follows. Since all components of the assay are securely immobilized on the electrode surface, there is no or just a negligible loss of redox mediators, cofactors, and/or enzymes over the time of operation. This is of importance for the performance and safety of a device because the impact of free-diffusing possibly toxic substances is minimized. Therefore, reagentless biosensor architectures are often used for in vitro and in vivo measurements as outlined in Sec lion 1.4.5. 

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A. Narvaez, G. Suarez, I. C. Popescu, I. Katakis, E. Dommguez, Reagentless Biosensors based on Self-deposited Redox Polyelectrolyte-oxidoreductases Architectures. Biosens. Bioelectron., 15 (2000) 43-52. 

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