Herein, we first report electrodeposition of dense (1.3 x 10(9) cm(-2)) and uniform (RSD of size is about 11%) Ag nanoflowers on ITO glass by a double-potentiostatic method without any surfactant. Raman spectra showed that the Ag nanoflowers with multiple petals on ITO glass exhibited excellent SER(R)S ability. It could accommodate a considerable range of sample concentrations (10(-10) M at least for rhodamine 6G). The smallest RSD of the intensities for 1651 cm(-1) Raman band of rhodamine 6G was about 14.1%, indicating good reproducibility. Through the time-dependent morphological evolution investigation and high-resolution transmission electron microscopy (HRTEM) analysis, the formation of petals was ascribed to the slow reduction rate and high nucleation driving force by electrical field concentration. (C) 2012 Elsevier Ltd. All rights reserved.