Provided herein are dual contrast agents or nanocomposite particles designed to enhance optoacoustic-ultrasonic imaging. The contrast agents or particles have a core designed to enhance response to incident transient ultrasonic pressure waves and at least two layers disposed around the core. The inner first layer is designed to effectively absorb incident transient optical waves, convert absorbed optical energy into heat and demonstrates significant thermal expansion and/or conversion of thermal energy into acoustic pressure. The outer second layer thermally insulates the inner layer from the surrounding aqueous environment and enhances the generation of transient ultrasonic pressure waves during optoacoustic-ultrasonic imaging and sensing. Also provided are methods of enhancing contrast in a tissue optoacoustic-ultrasonic imaging and producing enhanced optoacoustic images by contacting the tissue with the dual contrast agent or nanocomposite particles.
