Recent development of two-photon fluorescent probes for bioimaging

Abstract

Fluorescent probes are essential tools for studying biological systems. The last decade has witnessed particular interest in the development of two-photon excitable probes, owing to their advantageous features in tissue imaging compared to the corresponding one-photon probes. This review summarizes various types of two-photon probes that have been applied to bioimaging, categorized by the principles in the probe design and the target analytes, which would provide a basis for the future development of novel two-photon probes for tackling important biological issues.

A mitochondria-targeted ratiometric two-photon fluorescent probe for biological zinc ions detection

“…350–550 nm) that limits their application in subcellular organelles and deep-tissue, owing to the shallow penetration depth (less than 80 μm) as well as to photo-bleaching, photo-damage, and cellular auto fluorescence (Sensi et al, 2003; Que et al, 2008; Tomat et al, 2010; McRae et al, 2009; Meng et al, 2006; Zhou et al, 2010). Recently, Two-photon fluorescence (TPF) probes, which can be excited by two-photon absorption in the NIR wavelength, provided an opportunity to overcome the problems originated from the single-photon fluorescence technology (Denk et al, 1990; Yao and Belfield, 2012; Sarkar et al, 2013; Kim et al, 2014; Kim and Cho, 2015; Meng et al, 2012; Park et al, 2012; Sarkar et al, 2014; Jing et al, 2012; Zhang et al, 2014; Wang et al, 2014; Masanta et al, 2011; Zhang et al, 2013; Zhou et al, 2014; Yin et al, 2015). However, most of the reported two-photon fluorescent probes Zn 2+ are “turn-on” ones, using enhancement of the fluorescence intensity at only one wavelength as the detection signal.…”

A New Two-Photon Ratiometric Fluorescent Probe for Detecting Alkaline Phosphatase in Living Cells

“…Again, under these conditions, bioimaging applications are affected by such accompanying drawbacks as photobleaching, autofluorescence in cells and tissues, and shallow penetration depth (<100 µm) [22][23][24]. An ideal tool to overcoming such limitations is two-photon microscopy (TPM), which involves fluorophore excitation by two low-energy (longer wavelength) photons [25][26][27][28][29]. There are many excellent properties, such as large two-photon active absorption cross-section, high fluorescence quantum yield and good photo-chemostability about naphthalene derivatives with a donor-π-acceptor (D-π-A) structure, which has thus been employed extensively as an efficient two-photon platform for designing two-photon probes for various targets [30][31][32][33].…”

Engineering a FRET strategy to achieve a ratiometric two-photon fluorescence response with a large emission shift and its application to fluorescence imaging

“…To date, a large number of TPE fluorescent imaging probes have been developed that have greatly contributed to biomedical research. 5,6 However, most of the reported TPE sensing and imaging methods rely on fluorescence intensity changes, which are easily influenced by many factors, including photo-bleaching, microenvironments ( e.g. pH, polarity, temperature, and so forth), and local probe concentrations.…”