A new method for luminescence detection of [Ru(bpy)(2)tatp](2+)-based thin layer (where bpy = 2,2'-bipyridine, tatp = 1,4,8,9-tetra-aza-triphenylene) on a polyaniline (PANI)/ITO electrode in the absence and presence of herring sperm DNA tuned by applied electrode potentials has been developed under the excitation of CW green laser. It is found that the DNA-[Ru(bpy)(2)tatp](2+) conjugates are formed either in solution or on the PANI/ITO surface, exhibiting an effective enhancement in the luminescence by DNA. More interestingly, the application of anodic potentials significantly enhances the emission intensities of both [Ru(bpy)(2)tatp](2+) and DNA-[Ru(bpy)(2)tatp](2+) conjugates on the PANI/ITO surface excited with green laser. (C) 2010 Elsevier B. V. All rights reserved.