Among different types of fluorescent dyes, indocyanine green
is one of the most classical dyes, producing fluorescence in the
near infrared region of the spectrum. Therefore, it has been widely
used in fluorescent probes. It is also used for bioimaging of cells
and tissues, because it has weak background interference, causing
low photo-damage [3–7]. Furthermore, it penetrates deeply
into the tissues [3]. In general, most fluorescent dyes absorb UV
light of a shorter wavelength. However, cyanine and its derivatives
usually exhibit a deeper color because they absorb UV light of a
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E-mail addresses: yinj@mail.ccnu.edu.cn (J. Yin), jyoon@ewha.ac.kr (J. Yoon).
longer wavelength, which is usually over 700 nm. Therefore, they
are green or blue in color