A multistage volumetric bar chart chip for visualized quantification of DNA.

Nucleic acid detection is critical in disease diagnosis as well as in the environmental assays of harmful bacteria or viruses and forensic applications. Current methods for visualized quantification of DNA require costly and sophisticated instruments. Here, we report a multistage propelled volumetric bar chart chip (MV-Chip) for multiplexing and quantitative detection of DNA. Because of its "rocket-like" propelling reaction, the predeposited platinum films could perform cascade amplification and detect as low as 20 pM DNA targets after three stages of platinum-catalyzed propulsion. The resulting ink bar charts can be directly read out by the naked eye, and the signal shows little interference from serum. Single-nucleotide polymorphism and multiplex DNA detection were carried out to demonstrate this powerful application.