ABSTRACT
The redox reaction is the chemical reaction in which the oxidation number of chemical species changes by gaining or losing electrons. Redox reactions are very common and crucial to many basic functions of life, such as combustion, respiration, photosynthesis, and rusting. The large active metals lose electrons easily, so they are all reductants. Sodium amalgam and aluminum, which are commonly used in laboratories and in production, are good reductants. A few techniques and tools have been employed to design redox-responsive biosensors that can detect transient ROS burst and relevant redox events in living systems. Depending on the category of the ROS, the designed biosensors can also be classified as ONOO- sensitive biosensors, HbrO-sensitive biosensors, H2O2 sensitive biosensors, or O2 sensitive biosensors. Stimuli-responsive materials, which exhibit large and sharp changes in response to small variations of external parameters such as temperature, pH, and ionic strength, have been widely incorporated into porous polyelectrolyte membranes to fabricate stimuli-responsive membranes.
