Fiber Bragg Grating Sensors for Thermometry during Gold Nanorods-mediated Photothermal Therapy in Tumor Model

This work proposes the use of femtosecond laser-written fiber Bragg grating (FBG) sensors for the real-time monitoring of tumor temperatures during gold nanorod (GNR)-mediated photothermal therapy. Arrays of sub-millimetric FBGs enabled an accurate and spatially resolved temperature detection within subcutaneous breast tumors in mice. The measured maximum temperature increase in the GNR-treated group was 64 °C, while a maximum temperature change of 47 °C was registered among controls. Furthermore, the introduction of the tumor-localized GNRs resulted in an overall increase of 13 °C of the mean temperature change, compared to control. The proposed sensing solution permits to reduce the invasiveness of the sensing approach for fiber optic-based and quasi-distributed temperature monitoring in tissues undergoing photothermal therapy.