The development of instrument-free, PCR-less, ultrasensitive and selective DNA detection methods is highly desired in chemical and life sciences. Herein we report on the utility of a biomineralization-assisted amplification methodology for the identification of DNA. Significantly, the diagnostic strategy has allowed the target detection at a concentration as low as 50 aM, equivalent to similar to 180 copies in the entire 6 mu L sample. In addition, the DNA sequence with a single-base mismatch can be differentiated from the perfect target through a facile salt-based stringency wash. Substitution of the DNA structures with other recognition moieties should allow the translation of the strategy to the assay of different targets of interest. The visual readout format provides a sound basis for the broad applicability of the proposed strategy, especially in resource-poor settings.