A High-Sensitive and Low-Probe-Dosage Nanoprobe for Quantifying Hydrogen Peroxide Fluctuations in Physiological...

Area of Science:

• Biomedical Engineering
• Chemical Biology
• Molecular Imaging

Background:

• Hydrogen peroxide (H2O2) is crucial in cellular signaling, but its detection is challenging due to probe sensitivity and dosage limitations.
• Existing H2O2 probes often require high concentrations for effective imaging or suffer from low sensitivity, hindering accurate biological studies.

Purpose of the Study:

• To develop a high-sensitivity nanoprobe for H2O2 detection that minimizes probe dosage.
• To enable accurate elucidation of H2O2-related cellular signaling pathways and in vivo mechanisms.

Main Methods:

• A micelle-based nanoprobe (PMPC-Bpe-BHQ2@SQ) was synthesized by conjugating a quencher (BHQ2) and an H2O2 recognition site (Bpe) to a poly(carbonate) backbone, encapsulating a fluorescent dye (SQ-dye).
• The nanoprobe utilizes a dual-signal amplification mechanism: H2O2-triggered micelle activation and subsequent SQ-dye binding with cytoplasmic proteins.
• Utilized BHQ2 as a quenching agent and SQ-dye for fluorescence enhancement through interaction with cytoplasmic proteins.

Main Results:

• The nanoprobe achieved a 265.83-fold fluorescence enhancement, enabling a detection limit as low as 1 nM for H2O2.
• The dual amplification mechanism significantly reduced the required probe dosage, minimizing disruption to cellular H2O2 homeostasis.
• Enabled accurate imaging of growth factor-stimulated signaling pathways and testosterone-induced H2O2 production in vivo.

Conclusions:

• The developed nanoprobe offers a sensitive and efficient tool for H2O2 detection, overcoming limitations of existing methods.
• This approach facilitates a more precise understanding of H2O2's role in biological processes and disease mechanisms.
• Mitigates probe-induced disruption, paving the way for more reliable in vivo imaging and mechanistic studies.