Intracellular pH-sensing using core/shell silica nanoparticles

Area of Science:

• Nanobiophotonics
• Biomedical Engineering
• Cellular Biology

Background:

• Understanding cellular biochemical processes is crucial for disease diagnosis and treatment.
• Nanobiophotonics provides advanced tools for intracellular diagnostics and therapeutics.
• Fluorescent nanoparticles offer potential for real-time, in vivo monitoring of cellular analytes.

Purpose of the Study:

• To synthesize optical chemical nanosensors for quantitative intracellular pH analysis.
• To demonstrate the application of these nanosensors for monitoring pH in living cells.
• To evaluate the nanosensors' biocompatibility and response time.

Main Methods:

• Synthesis of silica-based nanoparticles (~70 nm) using a modified sol-gel Stöber method.
• Co-encapsulation of Texas Red (reference dye) and fluorescein isothiocyanate (pH-sensitive dye).
• Demonstration of nanosensor function in a live human embryonic kidney cell line.

Main Results:

• Nanosensors successfully quantified intracellular pH changes from acidic to basic conditions.
• High loading efficiency of nanoparticles into cells was observed.
• Minimal impact on cell morphology and a fast response time (~2 s) were noted.

Conclusions:

• The developed optical nanosensors are effective for intracellular pH monitoring.
• These nanosensors show promise for real-time analysis of cellular processes.
• The technology offers a powerful tool for diagnostics and research in cell biology.