Metal ions play a critical role in human health and abnormal levels are closely related to various diseases. Therefore, the detection of metal ions with high selectivity, sensitivity and accuracy is particularly important. This article highlights and comments on the coordination-induced structural changes of DNA-based optical, electrochemical and optical–electrochemical-combined sensors for metal ions detection. Challenges and potential solutions of DNA-based sensors for the simultaneous detection of multiple metal ions are also discussed for further development and exploitation.