Identification and Detection of Intracellular Reactive Sulfur Species Using a Reaction-Mediated Dual-Recognition...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Cell Biology

Background:

• Reactive sulfur species (RSS), including hydrogen sulfide (H₂S) and sulfur dioxide (SO₂), are crucial signaling molecules in physiological processes.
• Understanding the precise roles of H₂S and SO₂ is hindered by the lack of accurate and robust sensing methods in biological systems.

Purpose of the Study:

• To develop a novel nanosensor for the simultaneous and accurate detection of H₂S and SO₂ within living cells.
• To investigate the potential of a dual-recognition strategy for sensing reactive sulfur species.

Main Methods:

• Fabrication of silver nanoparticles (AgNPs)-loaded MIL-101 (Fe) (ALM) hybrid nanosensors.
• Utilizing a reaction-mediated dual-recognition strategy combining Surface-Enhanced Raman Spectroscopy (SERS) and fluorescence (FL) detection.
• Employing the ALM platform for simultaneous detection of H₂S and SO₂ in living cells, targeting mitochondria.

Main Results:

• The ALM nanosensor demonstrated simultaneous detection of H₂S and SO₂ with high sensitivity (2.8 × 10⁻⁶ μM for H₂S, 0.003 μM for SO₂).
• H₂S detection involved AgNP oxidation to Ag₂S, decreasing SERS signals, while SO₂ detection involved charge-transfer complex formation, increasing FL intensity.
• The platform showed minimal crosstalk between SERS and FL signals and enabled in-cell detection under external stimulation.

Conclusions:

• The developed ALM nanosensor provides a powerful tool for simultaneous detection of H₂S and SO₂ in living cells.
• This advancement facilitates a deeper comprehension of the physiological roles of RSS.
• The dual-modal sensing approach offers high sensitivity and specificity for complex biological analyses.