Femtosecond laser-induced X-ray fluorescence measurement of metal-protein compounds

Highlights: • Laser-induced X-ray generated with an aluminum tape target. • Characterized a laser-induced Kα and bremsstrahlung X-ray by change laser intensity and pulse focused position. • High accuracy and high stability X-ray fluorescence measured with a few micrograms of bio-metal sample. We measured the metal-protein compounds X-ray fluorescence by the laser-induced X-ray source with an aluminum tape target. The laser-induced X-ray generated by the high repetition rate (1 kHz) femtosecond (40 fs) Ti: Sapphire laser system. To characterize a laser-induced Kα and bremsstrahlung X-ray source, we changed the laser intensity and pulse focused position. We measured the X-ray fluorescence signal with the copper plate, selenium powder, lyophilized hemoglobin, and lyophilized seleno-methionine, which was detected by X-ray spectrometer. With a few micrograms of samples, the X-ray fluorescence can be measured with high accuracy and high stability.