Layer-by-layer assembly and morphological characterizations of DNA/layered double hydroxide thin films

Layered double hydroxides (LDHs), also known as hydrotalcite-like anionic clays, have been proposed as a potential biocompatible carrier for gene and drug molecules. Gene molecules (such as DNA and siRNA molecules) were either typically intercalated into the layer galleries of powdered LDH nanoparticles, or encapsulated within spherical LDH nanoshells. Herein, we describe a preparation of the (DNA/LDH)n ultrathin films via layer-by-layer (LbL) assembly between DNA and exfoliated LDHs nanosheets prepared by a scalable method. Atomic force microscopic observations show that the DNA/LDH monolayer consists of the linearly aligned DNA and the supported LDH nanosheets. Results of UV–vis spectra and XRD patterns reveal the homogenous LbL assembly of the resulting (DNA/LDH)n multiple thin films. Our results may initiate preparation of the integrated bio-LDH films with possible application in film sensors.

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► The (DNA/LDH)n ultrathin films were prepared via layer-by-layer (LbL) assembly.
► DNA/LDH monolayer film shows the assembly of the linearly aligned DNA.
► (DNA/LDH)n multilayer film exhibits the homogenous LbL assembly.