Self-Assembled Ti4+@Biospore Microspheres for Sensitive DNA Analysis.

Ti4+ can be chemically adsorbed and assembled on the surface of the modified spore to form highly monodispersed Ti4+@spore microspheres. Moreover, we for the first time found that these biomicrospheres exhibit differential affinities toward ssDNA and dsDNA. As a principle-of-proof, we exploited the self-assembled Ti4+@spore microspheres for a hybridization analysis. Interestingly, in the hybridization analysis, residual ssDNA probes are selectively adsorbed on Ti4+@spore microspheres at pH 5.0 and then removed via centrifugation. By taking advantage of this property, the signal-to-noise ratio for DNA analysis was considerably increased by reducing the noise caused by the residual ssDNA probes. The proposed method features easy operation, high specificity, and sensitivity and thus exhibits potential for further applications on DNA biosensing.