In vitro oxygen sensing using intraocular microrobots.

Area of Science:

• Biomedical Engineering
• Ophthalmology
• Materials Science

Background:

• Minimally-invasive diagnosis is crucial for intraocular conditions.
• Wireless sensing technologies are needed for precise in-situ measurements.
• Luminescence-based oxygen sensing offers high sensitivity.

Purpose of the Study:

• To develop a wireless intraocular microrobot equipped with a luminescence oxygen sensor.
• To enable accurate, minimally-invasive oxygen level monitoring within the eye.
• To demonstrate the feasibility of magnetic control and optical readout for intraocular diagnostics.

Main Methods:

• Integration of a Pt(II) octaethylporphine (PtOEP) luminescence dye with a polystyrene matrix for sensor coating.
• Fabrication of a magnetic microrobot for controlled navigation within the intraocular cavity using magnetic fields.
• Development of a frequency-domain lifetime measurement approach for wireless optical excitation and readout.
• Characterization of sensor performance including excitation/emission spectra, response time, and oxygen sensitivity.
• Design and construction of a custom device for intraocular measurements.

Main Results:

• Successful demonstration of a wirelessly controlled intraocular microrobot.
• The luminescence oxygen sensor exhibited characteristic spectral properties and response times.
• Oxygen sensitivity was confirmed through luminescence quenching in the presence of oxygen.
• An enhanced sensor design using poly(styrene-co-maleic anhydride) (PS-MA) and PtOEP nanospheres showed improved performance.

Conclusions:

• The developed luminescence oxygen sensor integrated with a wireless microrobot is a promising tool for minimally-invasive intraocular diagnosis.
• The magnetic control and optical readout system allows for precise, real-time oxygen monitoring in the eye.
• Further development of advanced sensor materials can enhance performance for clinical applications.