In this study, we proposed a simple and ultrasensitive approach called dynamic surface-enhanced Raman spectroscopy, which has been experimentally and theoretically demonstrated. The signal for rhodamine 6G is at least four orders of magnitude higher than that for the traditional method. A series of experiments have been exploited so as to verify the universality of our strategies. The results highlight a rapid and effective method in addictive narcotics residue apparatus, pesticide residue, crime scene or other public security field. Copyright © 2012 John Wiley & Sons, Ltd.