Anisotropic Gold Nanostars Functionalized with 2-Thiouracil: A Multifunctional Platform for Colorimetric Biosensing and Photothermal Cancer Therapy

This study presents a multifunctional theranostic platform based on anisotropic gold nanostars (AuNSs) functionalized with 2-thiouracil (2-TU) for cancer diagnostics and photothermal therapy (PTT). The unique plasmonic properties of AuNSs, combined with the anticancer and photothermal potential of 2-TU, were harnessed to create a system capable of simultaneous colorimetric biosensing and therapeutic action. Under dual-wavelength irradiation (660 nm and 525 nm), the AuNSs–2-TU conjugate demonstrated enhanced photothermal conversion efficiency, selective cancer cell targeting, and signal amplification, resulting in a significant reduction in the IC50 for MCF-7 breast cancer cells. The system exhibited minimal cytotoxicity to normal fibroblasts (WS1), ensuring therapeutic precision. Compared to conventional spherical gold nanoparticles, this platform provides superior multifunctionality, including real-time biosensing with simple, naked-eye colorimetric readouts. These results highlight the potential of the AuNSs–2-TU conjugate as an innovative, minimally invasive nanotheranostic platform suitable for integrated cancer detection and treatment, particularly in resource-constrained settings.