NIR Light-Responsive Hollow Porous Gold Nanospheres for Controllable Pressure-Based Sensing and Photothermal Therapy of Cancer Cells

Pressure-based signal transduction has attracted recent and extensive attention due to its high sensitivity and simplicity. The most popular way to generate gas pressure relies on catalyst-mediated decomposition of H 2 O 2 . Despite its high sensitivity, this method lacks spatial and temporal control of the reaction, and may suffer from variations due to the dead time of mixing. In this work, we report a new reaction using near-infrared (NIR) light to heat hollow porous gold nanospheres (AuNSs) for thermal decomposition of NH 4 HCO 3 . Comparisons were made on these two systems especially on controlled pressure production. As an example of application, our light-controlled system was used for the detection of MCF-7 cancer cells by attaching the S2.2 aptamer on the AuNSs. The detection limit was as low as 2 cells/mL. Meanwhile, the heat produced by the AuNSs was used to induce localized hyperthermia at the surface of the cancer cells. This interesting theranostic system provides new insights into pressure-based sensing and may inspire new analytical applications.