title: In vitro oxygen sensing using intraocular microrobots.
abstract: We present a luminescence oxygen sensor integrated with a wireless intraocular microrobot for minimally-invasive diagnosis. This microrobot can be accurately controlled in the intraocular cavity by applying magnetic fields. The microrobot consists of a magnetic body susceptible to magnetic fields and a sensor coating. This coating embodies Pt(II) octaethylporphine (PtOEP) dyes as the luminescence material and polystyrene as a supporting matrix, and it can be wirelessly excited and read out by optical means. The sensor works based on quenching of luminescence in the presence of oxygen. The excitation and emission spectrum, response time, and oxygen sensitivity of the sensor were characterized using a spectrometer. A custom device was designed and built to use this sensor for intraocular measurements with the microrobot. Due to the intrinsic nature of luminescence lifetimes, a frequency-domain lifetime measurement approach was used. An alternative sensor design with increased performance was demonstrated by using poly(styrene-co-maleic anhydride) (PS-MA) and PtOEP nanospheres.
authors.affiliation: Multiscale Robotics Laboratory, Institute of Robotics and Intelligent Systems, ETH Zurich, Zurich 8092, Switzerland. oergeneman@ethz.ch
authors.forename: Olgaç
authors.initials: O
authors.lastname: Ergeneman
authors.forename: George
authors.initials: G
authors.lastname: Chatzipirpiridis
authors.forename: Juho
authors.initials: J
authors.lastname: Pokki
authors.forename: Marta
authors.initials: M
authors.lastname: Marín-Suárez
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Sotiriou
authors.forename: Santiago
authors.initials: S
authors.lastname: Medina-Rodríguez
authors.forename: Jorge F Fernández
authors.initials: JF
authors.lastname: Sánchez
authors.forename: Alberto
authors.initials: A
authors.lastname: Fernández-Gutiérrez
authors.forename: Salvador
authors.initials: S
authors.lastname: Pané
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Nelson
mesh_terms: D000818:Animals; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005123:Eye / Q000737:chemistry*; D006801:Humans; D008163:Luminescent Measurements; D055616:Microtechnology / Q000295:instrumentation*; D008954:Models, Biological; D008991:Monitoring, Physiologic / Q000295:instrumentation; D054118:Nanospheres; D010100:Oxygen / Q000032:analysis*; D012371:Robotics / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted; D059015:Wireless Technology / Q000295:instrumentation*
chemical_list: D010100:Oxygen