Potassium ferricyanide is the chemical compound with the formula K3[Fe(CN)6]. This bright red salt consists of the coordination compound [Fe(CN)6]3-. It is soluble in water and its solution shows some green-yellow fluorescence.
Potassium ferricyanide is widely used as a chemical reducer in photographic processing to remove silver from negatives and positives (dot etching).
Potassium ferricyanide is used in many amperometric biosensors as an electron transfer agent replacing an enzyme's natural electron transfer agent such as oxygen as with the enzymeglucose oxidase.