Organic–inorganic nanostructures for luminescent indication in the near-infrared range

Amplifying and quenching of IR luminescence of colloidal Ag$_2$S quantum dots were revealed to take place when they couple to organic dye molecules of 3,3'-di-($\gamma$-sulfopropyl)-9-ethyl-4,5,4',5'-dibenzothiacarbocyanine betaine and erytrosine pyridinium salts, respectively. The observed effects are explained as due to the formation of organic–inorganic heterostructures with different mutual arrangement of electronic states of the dyes and the quantum dots.