Fig. 1. (a) Design of a theranostic fiber optical probe by carrying the NTR probe and BP/AuNS hydrogel on the fiber optic surface. (b) The fiber probe runs in a “plug-and-play” way for tumor theranostics.

Fig. 2. (a) Photon-induced temperature changes in air caused by the BP fiber, the Gr fiber, the GrO fiber, the MXene fiber, the CNTs fiber, and the bare fiber as a function of the pump power. (b) Absorption spectra of the BP, Gr, GrO, MXene, CNTs, and AuNS. (c) Fiber sensing (BP/AuNS, Gr/AuNS, GrO/AuNS, MXene/AuNS, CNTs/AuNS, and bare fiber) for detecting NTR in vitro. (d) Schematic of hydrogels with nanomaterials bonded to the optical fibers. (i) Photograph of the pre-prepared BP/AuNS hydrogel. (ii) SEM of the BP. (iii) TEM of the AuNS. (iv) Photograph of BP/AuNS hydrogel on the optical fiber. (v) Microscopic image of the BP/AuNS hydrogel on the optical fiber.

Fig. 3. (a) Influence of the BP content on the photothermal conversion of the BP/AuNS fiber. (b) The influence of high BP content on fiber fluorescence sensing. (c), (d) Sensing performance and calibration of the optical fiber probes [blank, pure BP, BP/AuNS(S30), BP/AuNS(S20), and BP/AuNS(S10)] for detecting NTR in vitro. (e) Influence of the AuNS concentration on fluorescence sensing. The fluorescent signal increases with increasing gold nanostars content. (f) Photon-induced temperature changes in air caused by the BP fiber, the BP/AuNP fiber, and the BP/AuNS fiber as a function of the pump power. (Inset: IR temperature images of the BP, the BP/AuNP, and the BP/AuNS fibers at a pump power of 200 mW). (g) Fluorescence intensity of different diameters of the fibers. (h) LODs of the optical fibers with different end diameters. (i) Temperatures of the different diameter fibers.

Fig. 4. (a) Fluorescent intensity of the BP/AuNS fiber increases with the rising NTR density. (b) The fluorescence retention rate of the fiber sensing with time variations. P < 0.0001. (c) The fluorescence retention rate of the fiber sensing with temperature variations. P < 0.0001.

Fig. 5. (a) Schematic of the BP/AuNS theranostic probe for the tumor model. (b) In vitro sensing of the pork liver tissues with a mixture of PBS-NTR-NTR probes. (c) Simulation of fiber PTT in air. (d) Simulation of fiber PTT treatment in a tumor model. (e) In vitro characterization of the fiber photothermal driven range as a function of the pump power. (f) In vitro characterization of the fiber photothermal driven range as a function of the heating time.