Pulse Hydrogen Treatment of Surface Layer of SPR Sensor

The pulse action of hydrogen on the SPR sensor was experimentally studied. The pulse regime was chosen by means of estimation of hydrogen concentration distribution in a gold film. Impulse was an impulse of electrolysis current with a duration of 2 seconds. The current impulses were repeated every half hour. The SPR curve after exposure to 60 impulses on the sensor shifted to the region of larger angles by 4.51°. The width of the SPR curve has increased 5 times. The amplitude of the resonant absorption of light has decreased significantly. After 60 impulses of hydrogen treatment the SPR sensor has become unsuitable for registration in accurate measurements. The theoretical modeling for changes of the morphology of thin gold film by means of hydrogen treatment was performed. The SPR curve changes were explained by hydrogen embrittlement of the upper layer of the gold film and, thus, by increasing of the surface roughness of the gold film.