Photothermal conversion efficiency and biocompatibility are two valuable factors of photothermal agents for photothermal therapy of tumors. However, the synthesis of efficient photothermal agents with desired biocompatibility remains a great challenge in the green synthesis due to harsh reaction conditions of existing methods. Herein, a green and facile biosynthetic method for preparing the photothermal agent (PTA) copper sulfide by cell-regulated was reported for the first time. The intracellular CuS nanoaggregates (nCuS) are biosynthesized using yeast cells as bioreactors and the functional yeast cells including the intercellular bio-PTA with photothermal effect are constructed (nCuS@yeast). The biomolecules derived from the yeast cells are used as conditioning and stabilizing mediator to regulate the biosynthesis of the nCuS. The biosynthetic nCuS exhibits a good biocompatibility and a high photothermal conversion efficiency (45.24%). Additionally, the absorption of internal nCuS in the near-infrared region is not affected by the cell wall, which is beneficial for photothermal therapy. In vitro and in vivo studies reveal the great potential of nCuS@yeast in tumor photothermal therapy. This research establishes a new and green avenue for the synthesis of biocompatible photothermal nanomaterials through a cell-based biosynthesis strategy, highlighting its potential application in the field of tumor therapy.

Quantitative analysis of dopamine (DA) in body fluids is essential owing to its close relation to some nervous system diseases. However, there are still significant challenges in exploring new materials with good sensitivity and biocompatibility for real-time medical monitoring. Herein, we developed the nano-MnO₂-modified red blood cell (RBC@MnO₂), a novel whole-cell electrochemical biosensor for detecting DA. The n-MnO₂ grown in situ on the cell surface can increase the transmembrane electron transfer rate and electrochemically active surface area of the catalyst. The as-prepared biosensor exhibits a high sensitivity (11.73 μA·μM⁻¹·cm⁻²), a low detection limit (0.068 μM), and a wide linear range (0.6–160 μM) toward DA detection, which can be applied for DA detection in real-time health monitoring in whole blood samples with satisfactory results.