Carica papaya-Derived Carbon Nanodots for the Detection of Fe (III) Ions

Carbon dots (CDs) possess distinctive optical and electronic properties as well as dimensions smaller than 10 nm, making them a unique category of carbon-based nanomaterials. They have been widely utilized across various domains including sensors, photocatalysis, biomedicine, and optoelectronics. This study investigates the use of a one-step hydrothermal synthetic approach to produce nanocarbon dots derived from Carica papaya seeds. Through the application of sophisticated characterization methods, the structural properties of the carbon nanoparticles were verified. These techniques included UV-visible absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and high-resolution transmission electron microscopy (HR-TEM). The photoluminescence emission of carbon dots (CDs) has been found to depend on excitation, as determined by photoluminescence (PL) spectroscopy. This study has explored the interaction between various metal ions and the photoluminescent properties of CDs, revealing a particularly noteworthy interaction with Fe (III) ions. The Stern-Volmer equation is utilized to examine the extinction mechanism linked with the sensing capability of carbon dots, resulting in the establishment of a recognition threshold of 0.36 μM. The existence of surface functional groups, which enable the formation of complexes with Fe (III) ions is a primary factor contributing to the sensing capabilities observed. This paper explores the fabrication and advancement of environmentally friendly sensor systems for detecting metal ions in biomedical and environmental contexts.