Quenching of nonlinear photoacoustic signal generation in gold nanoparticles through coating.

The photoacoustic signal generated from specific gold nanoparticles increases nonlinearly with respect to fluence. We demonstrate experimentally that this nonlinear behavior can be quenched with a particle coating, and present a theoretical analysis to explain this behavior. This effect has the potential to be developed into a photoacoustic-based biochemical sensor.