A Lifetime Nanosensor for In Vivo pH Quantitative Imaging and Monitoring

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Accurate in vivo biomarker monitoring is essential for disease research and precision medicine.
• Developing stable, quantitative chemical sensors for long-term in vivo use faces challenges like concentration variability and tissue interference.

Purpose of the Study:

• To develop a novel nanosensor for precise, quantitative, and long-term in vivo pH monitoring.
• To overcome limitations of existing sensors for sustained monitoring in biological environments.

Main Methods:

• Fabrication of a long-lifetime nanosensor using a lanthanide-dye nanocomposite.
• Utilizing reversible changes in molar extinction coefficient and non-radiative energy transfer (RNET) for pH sensing.
• Characterizing nanosensor performance, including luminescence lifetime and pKa shift due to nanomaterial interaction.

Main Results:

• The nanosensor demonstrated a 64-fold reversible change in molar extinction coefficient, enabling dynamic RNET efficiency tuning (6.42%-35.23%) and luminescence lifetime modulation (265-383 µs).
• Successfully monitored gastrointestinal pH dynamics in mice for 4 hours after proton pump inhibitor (PPI) administration.
• Observed significant shifts in dye pKa due to coordination with lanthanide nanocrystals, demonstrating the impact of interface engineering.

Conclusions:

• The developed nanosensor provides precise quantitative in vivo pH monitoring, overcoming key challenges.
• This technology offers new insights into drug pharmacodynamics and inter-individual variability in drug efficacy.
• Establishes a versatile platform for in vivo diagnostics and therapeutic monitoring, advancing precision medicine.