Plant viruses cause economic losses of several billion US dollars annually. The often non-specific symptoms of a virus infection and the great variability of plant virus genomes make reliable diagnoses a challenge. In the event of infection, rapid action is also required to prevent spread. However, appropriate analyses, such as one-step simultaneous detection of different viruses in an infected plant, are still difficult, if not impossible, with commercially available diagnostic kits. Biochemical sensor technology can help to detect a virus infection at an early stage.