A nanoscale molecular tag, comprising: (i) a core nanoparticle with a diameter of 30-80 nm and wherein the core nanoparticle comprises, a noble metal, such as gold or silver or both; (ii) an optional shell surrounding the core wherein said shell is selected from the group consisting of a layer of gold, silver, or both, noble metals; or includes nucleic acids or PEG; and (iii) an armor comprising a single-stranded DNA molecule having a first portion and a second portion, wherein the first portion comprises phosphorothioate DNA which reduces the valency of said nanoparticle to one functional binding site and is bound to the surface of the core nanoparticle, or if present, to the surface of the shell, and the second portion is not bound to the core nanoparticle or shell, and comprises a functionalized end with one binding site, characterized in that said functionalized end comprises a first binding partner that is capable of specifically binding to a second binding partner and wherein said first and second binding partner is selected from the group consisting of: i) benzylguanine and a SNAP-Tag; ii) benzylguanine and a CLIP-Tag; iii) biotin and streptavidin; iv) a single-stranded oligonucleotide and a complementary single-stranded oligonucleotide; v) a single-stranded oligonucleotide and an aptamer; vi) DCFPyL and prostate specific membrane antigen (PMSA); vii) a receptor and a ligand; viii) a ligand and a receptor; ix) an antigen and an antibody and x)an antibody and an antigen wherein any one of, or any combination of, the core, the shell and the armor contribute to fluorescence, light scattering and/or ligand binding properties of the molecular tag that are detectable by microscopy or a device that measures fluorescence and/or light scattering intensity or power; and wherein components (i) and (iii) or (i), (ii) and (iii) together provide the following functionalities: (a) light scattering intensity or power of the assembled structure is detectable above the specific level of the reference noise of the device detecting the light scattering intensity or power; (b) fluorescence intensity has sufficient brightness for detection above the limit of detection for the instrument; and/or (c) ligand specificity is conferred by a ligand binding component. (i) a core nanoparticle with a diameter of 30-80 nm and wherein the core nanoparticle comprises, a noble metal, such as gold or silver or both; (ii) an optional shell surrounding the core wherein said shell is selected from the group consisting of a layer of gold, silver, or both, noble metals; or includes nucleic acids or PEG; and (iii) an armor comprising a single-stranded DNA molecule having a first portion and a second portion, wherein the first portion comprises phosphorothioate DNA which reduces the valency of said nanoparticle to one functional binding site and is bound to the surface of the core nanoparticle, or if present, to the surface of the shell, and the second portion is not bound to the core nanoparticle or shell, and comprises a functionalized end with one binding site, characterized in that said functionalized end comprises a first binding partner that is capable of specifically binding to a second binding partner and wherein said first and second binding partner is selected from the group consisting of: i) benzylguanine and a SNAP-Tag; ii) benzylguanine and a CLIP-Tag; iii) biotin and streptavidin; iv) a single-stranded oligonucleotide and a complementary single-stranded oligonucleotide; v) a single-stranded oligonucleotide and an aptamer; vi) DCFPyL and prostate specific membrane antigen (PMSA); vii) a receptor and a ligand; viii) a ligand and a receptor; ix) an antigen and an antibody and x)an antibody and an antigen wherein any one of, or any combination of, the core, the shell and the armor contribute to fluorescence, light scattering and/or ligand binding properties of the molecular tag that are detectable by microscopy or a device that measures fluorescence and/or light scattering intensity or power; and wherein components (i) and (iii) or (i), (ii) and (iii) together provide the following functionalities: (a) light scattering intensity or power of the assembled structure is detectable above the specific level of the reference noise of the device detecting the light scattering intensity or power; (b) fluorescence intensity has sufficient brightness for detection above the limit of detection for the instrument; and/or (c) ligand specificity is conferred by a ligand binding component. i) benzylguanine and a SNAP-Tag; ii) benzylguanine and a CLIP-Tag; iii) biotin and streptavidin; iv) a single-stranded oligonucleotide and a complementary single-stranded oligonucleotide; v) a single-stranded oligonucleotide and an aptamer; vi) DCFPyL and prostate specific membrane antigen (PMSA); vii) a receptor and a ligand; viii) a ligand and a receptor; ix) an antigen and an antibody and x)an antibody and an antigen wherein any one of, or any combination of, the core, the shell and the armor contribute to fluorescence, light scattering and/or ligand binding properties of the molecular tag that are detectable by microscopy or a device that measures fluorescence and/or light scattering intensity or power; and (a) light scattering intensity or power of the assembled structure is detectable above the specific level of the reference noise of the device detecting the light scattering intensity or power; (b) fluorescence intensity has sufficient brightness for detection above the limit of detection for the instrument; and/or (c) ligand specificity is conferred by a ligand binding component.