Poster Presentation 2014 International Biophysics Congress

Two-photon photoacoustic microscopy for label-free bio-imaging based on microcavity transducer (#570)

Yongbo Wu 1 , Zhilie Tang 1 , Yan Chi 1 , Liru Wu 1 , Minfang Huang 1
  1. South China Normal University, Guangzhou, China

Label-free nonlinear imaging of biological cells holds the key to uncovering the fundamental mechanism in the cells with high resolution, and the two-photon excitation fluorescence imaging had been proposed in the past two decades. In order to improve the detection efficiency of two-photon signal, here, combining the two-photon absorption and photoacoustic detection, we demonstrate a method for two-photon photoaoustic imaging of biological cells. Our method is based on a microcavity detector with high sensitivity, which is developed based on the bulk modulus of gas five orders of magnitude lower than that of solid. To generate the two-photon photoacoustic signals, we used a high-repetition rate femtosecond laser to induce narrowband excitation. Combining a low-frequency modulation technique and the lock-in detection, the two-photon photoacoustic signal was detected, which is proportional to the square of the incident light energy. By scanning the excitation beam, we performed a two-photon photoacoustic label-free imaging of a biological cell.