Biocompatible colloidal nanomaterials are of great interest in the biomedical field due to their ability to modulate redox reactions that translates into antioxidant aides. Common wet syntheses processes utilized to obtain chalcogens nanoparticles have limitations such as low yield, high cost and use environmentally unfriendly chemical precursors and solvents. Pulsed laser ablation in liquids (PLAL) has shown to be an affordable, clean and rapid technique to produce chalcogen nanoparticles. Among the chalcogens, selenium (Se) has well-known capabilities of regulating the glutathione to reduced glutathione (GSH/GSSG) ratio, an established marker of ROS antioxidant activity in eukaryotic cells. Recently there has been an interest to include heavier chalcogens, e.g., tellurium (Te), in biological enzymatic interactions; however, due to its relative cytotoxicity, use of Te nanoparticles as an alternative to reduce glutathione, has not been fully investigated. In this work, we introduce the synthesis and characterization of a selenium-tellurium (SeTe) nano-alloy by PLAL using a deep eutectic solvent (DES), water and acetone as the liquid phase to exploit DES’s biocompatible composition and its influence on the PLAL synthesis kinetics that result in production of polycrystalline, sub-100nm nanoparticles. To investigate the formation of nano-alloy, we compare the features and properties of colloidal nanoparticles produced by PLAL at three wavelengths, 1064, 532 and 355 nm, respectively. We test bioactivity of SeTe nano-alloys, using A-375 (malignant melanoma) and C-33A (epithelial retinoblastoma) cells through assessing viability and proliferation to determine their capabilities towards use as anticancer treatments.