Electrochemical study of Catal ase Modi fied Electrode in t he Presence of Compatible and Non-Compati ble Osm olytes usi ng Carbon Nanotu bes

Catalase is an important antioxidant enzy me that converts H۲O۲ into water an O۲. Since H۲O۲ is important both clinically and environm entally, numerous eff orts have be en done in order to reduce the detecti on limit of nanosensors for H۲O۲. Catalase modified electrodes have been used for such a detection with promising results. Osmolytes play an influential role in various stresses and also in the prot ein stabilization. They are generally categorized in two major groups, those that do not p erturb the normal catalytic activity and structural stability of enzyme i.e. compatible osmolytes such as proline , and the others whi ch adversely affect structure and function to vario us degrees such as histidine. An enz yme modified electrode using multi-walled carbon nanotube and RTIL showed satisfactory results in terms of electr ode stability and res ponse. Effe ct of proline and hisitidi ne on various electroc hemical parameters wa s investigated. The formal potential (E°’) was fou nd to be -۰.۴۵۷ which showed good agreem ent with the values reported previ ously. In the presence of p roline, E°’ was increased and t herefore G decreas ed, which presents protein stabilization at the surface of ele ctrode and enhanced electron transferring wh ereas in the presence of hi stidine E°’ was pron ouncedly d ecreased an d (G increased) which bear testimony to protein destabili zation. In both cases th e peak cur rents were decreased; however such a decrease was much m ore promin ent in the presence of histidine rather than proline. The sta bilization effect coul d be utilize d in designing new nano-biosen sors for n umerous applications.

کلیدواژه ها:

Catalase ، Proline ، Histidine ، Osmolyte ، Electroche mistry ، Carb on nanotub e