Utilization of waste biomass of Poa pratensis for green synthesis of n-doped carbon dots and its application in detection of Mn2+ and Fe3

• Published in: Chemosphere (Oxford) 2022-01, Vol.286, p.131764-131764, Article 131764
• Main Authors: Krishnaiah, Prakash, Atchudan, Raji, Perumal, Suguna, Salama, El-Sayed, Lee, Yong Rok, Jeon, Byong-Hun
• Format: Article
• Language: English
• Subjects: Carbon dots; Carbonization; Fluorescence sensors; Kentucky bluegrass; Metal ion detection
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2021.131764

In this study, a novel and sustainable approach was used to synthesize nitrogen-doped carbon dots (NCDs) from the waste biomass of Poa Pratensis (Kentucky bluegrass (KB)) by a facile hydrothermal method. The prepared KBNCDs were subjected to various characterization techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and Fourier-transform infrared spectroscopy to verify the formation of carbon dots and their surface functional groups. The KBNCDs exhibited good hydrophilic fluorescence (FLU) properties with an acceptable quantum yield (7%). The synthesized KBNCDs showed excitation wavelength-dependent FLU emission behavior with strong cyan-blue FLU upon irradiation with 365 nm UV-light. The hydrophilic optical properties of the as-synthesized KBNCDs were used to detect Fe3+ and Mn2+ ions in an aqueous medium with good selectivity and sensitivity. It was found that the FLU of the KBNCDs is quenched in the presence of Fe3+ and Mn2+ ions, and the quenching rate was linear with the concentration of Fe3+ and Mn2+ ions. The limit of detection (LOD) of KBNCDs with metal ions was calculated using the Stern–Volmer relationship. The LOD values for Fe3+ or Mn2+ ions were calculated as 1.4 and 1.2 μM, respectively with the detection range from 5.0 to 25 μM. Based on these results, this study provides an underpinning for the development of KBNCD as FLU sensors that can be used in aqueous media. [Display omitted] •A novel fluorescent KBNCDs were prepared from the waste biomass of Poa Pratensis.•As-synthesized KBNCDs were used for selective detection of Mn2+ and Fe3+ ions.•Calculated detection limits of Mn2+ and Fe3+ ions are 1.2 and 1.4 μM, respectively.•First time reporting the detection of Mn2+ ion using KBNCDs in aqueous medium.•This study underpinning the development of CDs as FLU sensor from waste biomass.