Smartphone-based detection of unlabeled DNA via electrochemical dissolution.

We describe a novel approach that enables unlabeled biomolecules and chemical analytes to be detected using ordinary smartphone optics. Electrochemical reactivity of chromium, ordinarily considered detrimental, is harnessed here to generate a signature that can be easily seen by monitoring electrode dissolution under ordinary white-light illumination. The simplicity and robustness of this approach eliminates the need for labeling and/or pre-programming with specific receptors (e.g., oligonucleotide probes), making it feasible to greatly expand availability of a host of assays where detection complexity is a limiting constraint.