Ultrasensitive Detection and Cellular Photothermal Therapy via a Self-Photothermal Modulation Biosensor

摘要

The use of light, which is s a powerful tool for imaging and sensing, hasalso become one of the most prospective strategies in tumor treatment.Optical microfibers, which have engineerable waveguiding properties, arehighly attractive for optical sensing and photothermal therapy on the micro/nanoscale. However, for their real-world application, the sensitivity limitneeds to be addressed, as does the issue of improving the intrinsic photothermalperformance of silica microfibers. Herein, a nanointerface consistingof triangular Au@Ag2S nanoplates and VO_2 nanoparticles on an optical microfiberis designed to fabricate a structurally resilient hierarchical microfibersensor with well-distributed plasmonic hotspot enhancement. The nanointerfaceenhances the evanescent field with temperature tunability, adding aself-photothermal modulation function to the sensor. The sensor exhibits atemperature-tunable sensitivity to alpha-fetoprotein with a limit of detectionof 0.62 × 10~(?18) m. It differentiates hepatoma carcinoma cells from normal cellsand provides photothermal therapy aimed at the former. Quantitative evaluationof the sensor indicates that photothermal therapy kills more than 82%of cancer cells using a lower power. This work provides a new opportunity forselective evanescent field modulation for evanescent biosensors as well as apotential approach to the integration of cellular diagnosis and therapy.