An Nd³⁺-Sensitized Upconversion Fluorescent Sensor for Epirubicin Detection.

Area of Science:

• Nanomaterials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Accurate detection of chemotherapy drugs like epirubicin (EPI) is crucial for effective treatment and monitoring.
• Existing detection methods may lack sensitivity, speed, or applicability for in vivo scenarios.
• Upconversion nanoparticles offer unique optical properties for sensitive bio-detection.

Purpose of the Study:

• To develop and characterize an Nd³⁺-sensitized upconversion fluorescent sensor for epirubicin (EPI) detection.
• To evaluate the sensor's performance in aqueous solutions and biological samples (urine).
• To explore the potential of the sensor for in vivo imaging and detection.

Main Methods:

• Utilized Nd³⁺-sensitized upconversion nanoparticles for fluorescence sensing.
• Employed fluorescence resonance energy transfer (FRET) mechanism for EPI detection.
• Quantified EPI in aqueous solutions and spiked urine samples using spectrofluorometry.
• Investigated sensor properties relevant to in vivo applications, including autofluorescence and heating effect.

Main Results:

• Achieved sensitive detection of EPI with a dynamic quenching constant of 2.10 × 10⁴ M^-1.
• Demonstrated a linear response of normalized fluorescence intensity to EPI concentration from 0.09 μM to 189.66 μM.
• Established a fluorometric detection limit of 0.05 μM for EPI.
• Obtained high spike recoveries (97.5%–102.6%) in urine samples, indicating practical applicability.
• Highlighted weak autofluorescence, low heating effect, and high light penetration depth as advantageous for in vivo use.

Conclusions:

• The developed Nd³⁺-sensitized upconversion fluorescent sensor provides a simple, fast, and low-cost method for EPI detection.
• The sensor is effective for quantifying EPI in biological matrices like urine.
• The sensor's properties suggest significant potential for future in vivo imaging and therapeutic drug monitoring.