Ratiometric ECL sensor based on Apt-AuNS@Lu nanoprobe for analyzing cell swelling-induced ATP release

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Cell Biology

Background:

• Adenosine triphosphate (ATP) is a crucial signaling molecule released by cells under stress.
• Monitoring ATP release is vital for understanding cellular responses to stimuli like hypotonicity.
• Existing methods for ATP detection may lack sensitivity or specificity for real-time cellular studies.

Purpose of the Study:

• To develop a novel ratiometric electrochemiluminescence (ECL) system for sensitive and selective detection of hypotonicity-induced ATP release from HepG2 cells.
• To investigate the kinetics of ATP release from HepG2 cells under hypotonic conditions.
• To establish a robust analytical platform for studying cell biological functions using ECL technology.

Main Methods:

• Construction of a ratiometric ECL system using gold nanostars (AuNSs) as a support for luminophores and ATP aptamers.
• Immobilization of ATP aptamers on AuNSs decorated reduced graphene oxide/polydopamine (RGO/PDA) modified ITO electrodes.
• Utilizing AuNS@Lu nanoprobe and K2S2O8 as luminophores and co-reactants for ECL signal generation.
• Quantitative determination of ATP based on the ratio of ECL signals from the two luminophores.
• Application of the sensor to analyze ATP release from HepG2 cells exposed to hypotonic solutions (0.45% NaCl).

Main Results:

• The developed sensor exhibited a linear range of 5-250 nM ATP with a low limit of detection (1.4 nM).
• The sensor successfully monitored ATP release from HepG2 cells under hypotonic stress, showing a sigmoidal release profile.
• Hypotonic stimulation (0.45% NaCl) led to a significant decrease in intracellular ATP and a substantial increase in extracellular ATP levels within 10 minutes.
• The results demonstrated good agreement with commercial ELISA tests, validating the sensor's performance.

Conclusions:

• The novel ratiometric ECL system based on AuNSs provides a sensitive and reliable platform for detecting ATP release from cells.
• The study elucidates the kinetics of ATP release from HepG2 cells under hypotonic stress, offering insights into cellular responses.
• This ECL-based strategy holds promise for advancing the study of cell biological functions and developing new diagnostic tools.