Certain heavy metals can pose potential health risks when consumed by humans due to their high toxicity. Specifically, the heavy metals mercury, lead and cadmium can be released into the environment through industrial use and leakage from dump sites and once released can contaminate water, soil and air. These heavy metals can not be broken down in the human body and their accumulation over time can result in serious health risks. Consequently, there is an urgent need to develop novel device/tool for highly sensitive, selective, rapid, reliable, field-deployable and cost-effective detection of heavy metals. Zinc oxide (ZnO) nanostructures, as important promising candidates for support material, have many advantages in protein/peptide immobilization due to its friendly microenvironment and biomimetic and high electron communication features. We report herein a biosensor for determination of heavy metals based on hydrothermally grown ZnO nanorod/nanotube and metal-binding peptides. Heavy metal binding with peptide causes the electrical signal change which measured and correlated to the concentration of heavy metals. The sensor performance was optimized with respect to the operating conditions. The new biosensor offers great promise for rapid environmental mornitoring of heavy metals.