Specific two-photon fluorescent probe for cysteine detection in vivo

Area of Science:

• Biochemistry
• Chemical Biology
• Analytical Chemistry

Background:

• Cysteine (Cys) is an essential amino acid vital for numerous biological functions.
• Accurate detection of Cys is crucial for diagnosing various diseases.
• Developing rapid and specific fluorescent probes aids in studying Cys-related disease mechanisms.

Purpose of the Study:

• To develop a novel fluorescent probe, ANP, for the selective detection of Cys.
• To evaluate the probe's performance in distinguishing Cys from other biologically relevant thiols like Hcy and GSH.
• To demonstrate the probe's utility for in vivo Cys detection in living cells and tissues.

Main Methods:

• Synthesis of the ANP fluorescent probe based on 6-acetyl-N-methyl-2-naphthyl amine.
• Investigation of the probe's response to thiols, specifically Cys, Hcy, and GSH.
• Determination of the limit of detection and fluorescence enhancement upon Cys binding.
• Assessment of the probe's two-photon efficiency and suitability for live-cell imaging.
• Application of the probe for monitoring Cys distribution in live cells and tissues.

Main Results:

• The ANP probe exhibited an 87-fold fluorescence turn-on response upon reaction with Cys.
• A low limit of detection (65 nM) was achieved for Cys.
• The probe demonstrated high selectivity for Cys over Hcy and GSH.
• ANP possesses high two-photon efficiency (cross-section = 22.3), enabling effective live-cell imaging with minimal background fluorescence.
• Successful monitoring of Cys distribution in live cells and tissues was achieved.

Conclusions:

• The developed ANP probe is a highly sensitive and selective tool for Cys detection.
• Its excellent two-photon properties make it suitable for in vivo bioimaging applications.
• ANP facilitates the study of Cys's role in biological processes and disease mechanisms.