This method of detecting heavy metals is advantageous because it is simple, quick, and does not require any complex equipment or procedures. It is also highly sensitive and can detect even small amounts of heavy metals in a sample. Figure visually represents the temperature variations resulting from the interaction between heavy metals and the protease enzyme. The y-axis displays the temperature difference (Tf -Ti) and change in temperature (∆T), while the x-axis indicates the specific heavy metals tested. Each block in the graph signifies the change in temperature (∆T), with the initial temperature (Ti) and final temperature (Tf) clearly marked at the lower and upper edges of the blocks, respectively. Notably, copper and mercury exhibit the most substantial temperature increase, followed by chromium and cadmium. This graph visually demonstrates the distinctive impact of different heavy metals on the temperature profile of the protease enzyme. In our experiment, we examined our biosensor on a variety of heavy metal salt solutions, which were prepared with 1% concentration. Each solution showed a gradual rise in the temperature reading as soon as the biosensor was dipped in them, confirming the heavy metal contaminants in the solutions. The change in temperature for each heavy metal solution was calculated as ∆T, which is the difference between the final temperature Tf and the initial temperature Ti. The results are shown in Table .