Open AccessFluorescence enhancement of small squaraine dye and its two-photon excited fluorescence in long-term near-infrared I&II bioimaging
Author(s) -
Rongxing Yi,
Pintu Das,
Feifei Lin,
Binglin Shen,
Zhigang Yang,
Yihua Zhao,
Hong Liang,
Ying He,
Rui Hu,
Jun Song,
Junle Qu,
Liwei Liu
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.012360
Subject(s) - photobleaching , fluorescence , two photon excitation microscopy , materials science , infrared , absorption (acoustics) , excited state , fluorescence lifetime imaging microscopy , bovine serum albumin , optics , optoelectronics , photochemistry , chemistry , physics , atomic physics , composite material , biochemistry
Two-photon excited fluorescence (TPEF) plays an important role in bioimaging, the longer excitation wavelength improves its imaging depths, which gives us deeper biological information. Here, we reported the two-photon absorption of a small squaraine dye (SD), and we found that the TPEF of the small SD can be enhanced significantly using albumin, the TPEF of SD in water was enhanced 17.7 times by adding bull serum albumin (BSA) in the solution. Meanwhile, the cell imaging results indicated that the SD can enter cell effectively in less than 30 min and emit bright TPEF. Furthermore, the SD showed excellent stability against photobleaching in near-infrared II (1200 nm). The cytotoxicity experiment showed that the cytotoxicity of SD is relatively low. Our work demonstrates the excellent two-photon effect of SD in cells, potential application value of SD in two-photon bioimaging, protein detection and near infrared sensing.