Abstract: An apparatus configured to increase photoluminescence, generated by a substantially monolayer 2D heterostructure having a heterojunction, by at least several orders of magnitude. A method for use of same in the regime when such heterojunction is placed between pieces of a plasmonic material with a sub-nanometer distance therebetween.

Abstract: Methodology of Surface-Enhanced Raman Spectroscopy with the use of a rough Al substrate to image the biochemical composition of only the plasma membrane (and substantially without the contribution, to the SERS, of the contents of the inside of an imaged cell, thereby differentiating one from another) of intact cancerous cells and intact normal non-cancerous cells. The judiciously generated roughness of the Al substrate resulted in formation of many hot spots that provided a uniform membrane signal. The peak ratios of the resulting Raman signals specific to the cell-membrane only exhibited heterogeneous properties of the membrane with different lipid and protein concentrations at different spatial locations and are identified and can be used as novel cancer biomarkers. The proposed methodology may be extended to studying the nanoscale composition of lipid rafts and protein aggregates in intact biological cells.