Electrochemical flow-through biosensors based on microfiber enzymatic filter discs placed at printed electrodes.

A new type of electrochemical biosensors in a flow injection system with printed electrodes were developed and tested. A filter disc (7 mm diameter) with immobilized enzyme was placed at the printed electrode. This conception combines the advantages of biosensors with a bioreceptor at the electrode surface and systems with spatially separated enzymatic and detection parts.

Influence of different covalent immobilization protocols on electroanalytical performance of laccase-based biosensors.

This paper presents a simple and effective flow-through electrochemical biosensor, consisting of Trametes versicolor laccase (Lac)-based mini-reactor and a tubular detector of silver solid amalgam (TD-AgSA), capable of rapid and selective detection of phenolic compounds. Amperometric detection relies on the reduction of the quinone molecule (formed during the enzymatic reaction in a mini-reactor) on TD-AgSA at -50 mV vs SCE. Since different enzyme immobilization techniques may contribute to differing biosensor performances, four covalent strategies for Lac attachment were compared: (i) through glutaraldehyde to supports -NH, (ii) via disuccinimidyl suberate to supports -NH, (iii) using EDC/NHS for Lac coupling by its -COOH groups to supports -NH, and (iv) using EDC/NHS to supports -COOH.

Investigation of protein FTT1103 electroactivity using carbon and mercury electrodes. Surface-inhibition approach for disulfide oxidoreductases using silver amalgam powder.

Recently, it was shown that electrochemical methods can be used for analysis of poorly water-soluble proteins and for study of their structural changes and intermolecular (protein-ligand) interactions. In this study, we focused on complex electrochemical investigation of recombinant protein FTT1103, a disulfide oxidoreductase with structural similarity to well described DsbA proteins. This thioredoxin-like periplasmic lipoprotein plays an important role in virulence of bacteria Francisella tularensis.

Flow electrochemical biosensors based on enzymatic porous reactor and tubular detector of silver solid amalgam.

A flow amperometric enzymatic biosensor for the determination of glucose was constructed. The biosensor consists of a flow reactor based on porous silver solid amalgam (AgSA) and a flow tubular detector based on compact AgSA. The preparation of the sensor and the determination of glucose occurred in three steps.