Plasmonic Gold Nanoparticles for Combined Photoacoustic Imaging and Plasmonic Photothermal Therapy Using a Pulsed Laser

Plasmonic gold nanoparticles show potential for use in a range of cancer diagnostics and therapeutics, such as photoacoustic imaging (PAI) and plasmonic photothermal therapy (PPTT). Generally in PPTT, continuous wave (CW) lasers are used to destroy cancerous tissue. However, in order to add a diagnostic component through PAI, a pulsed wave (PW) laser is needed. If PPTT can be achieved using PW lasers then combined theranostic applications with the same laser system is possible. Additionally, AuNRs can be many different sizes but exhibit equivalent surface plasmon resonances, so the size may be significant in the efficacy of these modalities. We have demonstrated the potential for gold nanorods to be used for both PAI and PPTT. The Au10s displayed the highest photoacoustic signal amplitude and PPTT efficacy. A PW laser was shown to induce significant cell death to a lung cancer cell line with a fluence below the maximum permissible exposure, indicating the possibility for cancer theranostics with a PW laser.