GPT and liver disorder: In this work, a fast, small, and economic ALT biosensor is proposed for assisting the development of a convenient diagnosing technique for liver diseases.(1)L−alanine + α−ketoglutarate→ALTL−glutamate + pyruvate(2)L−glutamate + O2 →GlutOx α−ketogularate + NH3 + H2O2 (3)H2O2→O2+2H+ + 2e−