Facile Synthesis of Zinc Alloyed Cadmium Selenide (Cd/ZnSe) Quantum Dots and its Photocatalytic Activity and In Vivo Toxicity Assessment in Danio rerio Embryos

Zinc-alloyed cadmium selenide (Cd/ZnSe) quantum dots (QDs) were synthesised in a wet chemical method using thioglycolic acid as a stabilising agent. This facile synthesis method does not require high-temperature or inert gas (argon or nitrogen) atmosphere as required in prevailing methods. Also, this method does not require pyrophoric compounds such as trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO). The synthesised QDs were characterised using a spectrofluorometer, Fourier transform infrared (FT-IR) spectrometer, zeta potential, fluorescence lifetime spectrometer, ICP-OES, and selected area electron diffraction (SAED). The synthesised QDs were spherical with an average diameter of 5.08 nm and has a carboxyl group on their surface making them readily soluble in water and are biologically compatible. The QDs were evaluated for visible light–induced photocatalysis of Rhodamine 6G, and around 68% of the dye was degraded with 60 min of visible light irradiation. The synthesised QDs were tested for its toxicity in Danio rerio embryos including survival percentage, percentage of hatching, heartbeat counts and body length. Based on the toxicity evaluation, along with the presence of the carboxyl group on their surface, these QDs can harbour targeting molecules which will serve as a less toxic molecular imaging probe. Graphical Abstract Zinc-alloyed cadmium selenide quantum dots were synthesised using short-chain thiol compound—thioglycolic acid, evaluated for its optical and structural properties. The QDs were evaluated for their photocatalytic activity using Rhodamine 6G. These QDs were tested for their aquatic toxicity on Danio rerio embryos.