A biosensor chip for detecting electrochemical signals is disclosed. In some embodiments, the biosensor chip is two-sided and includes three electrodes. In some embodiments, the biosensor chip has a working electrode and a counter electrode that are spatially close to one another. In some embodiments, the base material of the biosensor chip has three protruding tabs that are each a different size than the other protruding tabs. The biosensor may be combined with a holey container to form a detection well.
