Supramolecular Hybrid Material Constructed from Graphene Oxide and Pillar[6]arene-Based Host-Guest Complex as a Ultrasound and Photoacoustic Signals Nanoamplifier.

Photoacoustic imaging combines the merits of ultrasound imaging and optical imaging that allows a fascinating imaging paradigm with deeper tissue penetration than optical imaging and higher spatial resolution than ultrasound imaging. Herein, we develop a supramolecular hybrid material composed of graphene oxide (GO) and a pillar[6]arene-based host-guest complex (CP6⊃PyN), which can be used as a ultrasound (US) and photoacoustic (PA) signal nanoamplifier. Triggered by the near-infrared (NIR) light mediated photothermal effect, CO2 nanobubbles are generated on the surface of GO@CP6⊃PyN due to the decomposition of bicarbonate counterions, thus strongly amplifying its US and PA performances. Our study, for the first time, demonstrates enhanced US and PA activity in supramolecular hybrid material on the basis of host-guest chemistry as a photoacoustic nanoplatform.