Metal assisted chemical etch has recently come to prominence as a
versatile strategy for the realization of silicon nanostructures with
tailored porosity. By exploiting metal assisted chemical etch, we
recently developed porous silicon nanoneedles capable of
interfacing with cells for delivery to and sensing of the intracellular
milieu. Here we review our recently published studies on the
fabrication of such nanostructures. Further we review their use as
vectors for the localized delivery nucleic acids capable of inducing
neovasculature formation in a mouse model. Finally we provide an
overview of our findings on the use of porous silicon nanoneedles
as intracellular sensors for detection of enzymatic activity with
high resolution across excised human tissue samples.