The Hidden Heroes: Holes in Charge-Driven Desorption Mass Spectrometry.

Photoexcited hot carriers have high impacts on various fields. However, in contrast to the attention attracted by the hot-electrons, the contributions of holes are seldom recognized. Yet, by simply removing the hot-electrons but retaining the holes on the surface of photoexcited plasmonic gold nanoparticles, a 60-fold ion intensity amplification could be achieved in laser desorption ionization mass spectrometry. A new desorption mechanism termed "charge-driven desorption" has been derived to rationalize the significant improvement.