A nanoparticle having a self assembly monolayer of molecules as a shell on the nanoparticle. The monolayer may include organic molecules working as surface enhanced Raman spectroscopy (SERS) reporters. Also, the core shell may include at least a receptor, and/or the like, to ensure that a target analyte can be bound for measurement with SERS. The target analyte may be organic, chemical, biological, inorganic, gas, liquid, solid, and so forth.