Silver nanocluster films as novel SERS substrates for ultrasensitive detection of molecules

► Silver nanocluster films as novel SERS substrates were prepared by cluster deposition method. ► A systematic study of SERS activity of R6G (10−4-10−16 M) on these substrates is carried out. ► For the first time the detection limit of R6G of 10−16 M has achieved. ► These SERS substrates are highly reproducible, active and more stable. ► The single molecule detection of R6G has achieved with these substrates.