Aim. Alanine aminotransferase (ALT) is an enzyme mostly found in heart and liver cells. Therefore, its blood content is often used as a non-selective biomarker of damage to these organs and helps diagnose such diseases as cirrhosis, hepatitis, myocardial infarction, stroke, etc. Since these diseases usually result in a patient’s critical condition requiring immediate medical aid, the availability of a fast, accurate, portable and easy-to-use method for ALT blood level detecting is a necessity. Currently, clinical research of ALT level is conducted using such methods as spectrometry and immunoassay, which can’t meet all the needs of doctors. In contrast, biosensors have the potential for miniaturization, automation, and cost reduction of analysis. Therefore, it was decided to develop biosensors for determining the level of ALT in biological solutions. Conclusions. It was shown that the biosensor based on glutamate oxidase is easier to use and more stable due to the smaller number of coenzymes. However, the biosensor based on pyruvate oxidase is preferred when creating more advanced biosensor system for the simultaneous determination of ALT and AST (another biomarker of heart and liver diseases, which is often determined simultaneously with ALT for more accurate diagnosis and has one common stage of the enzymatic reaction), as it allows to separate the signal from these two enzymes.