L lysine is a necessary amino acid that must be received through diet as the body is unable to synthesize it. As well as having uses in medicine and diagnostics, the De termination of L Lysine is significant for the pharmaceutical and food sectors. In a healthy human serum sample, 150 250 μmol/l of L lysine is considered normal. In certain illnesses, there is an imbalance in the amounts of L lysine. It could therefore be a biomarker for diagnosis. There are several fundamental techniques for determining L lysine, including chromatographic, radioisotope dilution, colorimetric, fluorometric, and voltammetric techniques. Some drawbacks of these procedures include the need fo r specialized staff, sample preparation, expense and time. Because of their great sensitivity, stability, and specificity, biosensors help to overcome these limitations. The current review paper addresses the fundamentals, benefits, and drawbacks of sever al analytical techniques for determining L lysine, with a focus on biosensors. pH levels between 5 and 10, potential ranges between 0.05 and 1.5 V, temperature ranges between 25 and 40 ◦C, linear ranges between 0.01 and 5500 μM, detection limit between 0.000004 and 650 μM, and response times of 2 are excellent for L lysine biosensors. The best conditions for L lysine biosensors to function include pH 5 to 10, the potential range ~0.05 to 1.5 V, temperature 25 to 40 ◦C, linear range 0.01 to 5500 μM, detection limit 0.000004 to 650 μM, and response time 2.