The　four　heteronuclear　clusters　[Ag2Au2(mu-dpppy)(3)(C　CC6H4R-4)(2)](ClO4)(2)　(R　=　H　(1)　CH3　(2),　COOCH3　(3),　CHO　(4))　were　prepared　by　the　self-assembly　reaction　between　(AuC　C6H4R-4)(n)　(R　=　H,　CH3,　COOCH3,　CHO)　and　[Ag-2(mu-dpppy)(3)](2+)　(dpppy　=　2,6-bis(diphenylphosphino)pyridine)　and　characterized　by　elemental　analyses,　electrospray　ionization　mass　spectrometry　(ESI-MS),　and　H-1　NMR　and　P-31{H-1}　NMR　spectroscopy　and　by　X-ray　crystallography　for　1,　3,　and　4.　It　is　revealed　that　the　complexes　exhibit　bright　blue　(1-3)　and　green　(4)　luminescence　in　the　solid　state　and　in　solution　with　the　luminescent　lifetimes　in　the　microsecond　range,　indicating　that　the　luminescence　is　most　likely　associated　with　a　spinforbidden　triplet　parentage.　Interestingly,　only　complex　4　displays　distinctly　mechanical　grinding　responsive　emission　switching.　The　recognition　interactions　of　complex　4　containing　aldehyde　groups　with　homocysteine　(Hcy)　and　cysteine　(Cys)　have　been　studied　by　UV　vis　and　emission　titrations.　A　strong　luminescence　quench　was　found　upon　reaction　of　complex　4　only　with　Hcy　or　Cys,　but　not　with　other　amino　acids,　proteins,　and　common　anions,　indicating　a　high　specificity　for　recognition　of　Hcy　and　Cys.