title: Biological and catalytic applications of green synthesized fluorescent N-doped carbon dots using Hylocereus undatus.
abstract: In this work, a simple hydrothermal route for the synthesis of fluorescent nitrogen doped carbon dots (N-CDs) is reported. The Hylocereus undatus (H. undatus) extract and aqueous ammonia are used as carbon and nitrogen source, respectively. The optical properties of synthesized N-CDs are analyzed using UV-Visible (UV-Vis) and fluorescence spectroscopy. The surface morphology, elemental composition, crystallinity and functional groups present in the N-CDs are examined using high resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS), selected area electron diffraction (SAED), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy, respectively. The synthesized N-CDs emit strong blue fluorescence at 400nm under the excitation of 320nm. Further, the excitation dependent emission properties are also observed from the fluorescence of synthesized N-CDs. The HR-TEM results reveal that synthesized N-CDs are in spherical shape with average diameter of 2.5nm. The XRD pattern exhibits, the graphitic nature of synthesized N-CDs. The doping of nitrogen is confirmed from the EDS and FT-IR studies. The cytotoxicity and biocompatibility of N-CDs are evaluated through MTT assay on L-929 (Lymphoblastoid-929) and MCF-7 (Michigan Cancer Foundation-7) cells. The results indicate that the fluorescent N-CDs show less cytotoxicity and good biocompatibility on both L-929 and MCF-7 cells. Moreover, the N-CDs show excellent catalytic activity towards the reduction of methylene blue by sodium borohydride.
authors.affiliation: Department of Chemistry, Gandhigram Rural Institute-Deemed University, Gandhigram 624 302, Dindigul District, Tamilnadu, India.
authors.forename: Velusamy
authors.initials: V
authors.lastname: Arul
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea. Electronic address: jebakumar84@yu.ac.kr.
authors.forename: Thomas Nesakumar Jebakumar Immanuel
authors.initials: TN
authors.lastname: Edison
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea. Electronic address: yrlee@yu.ac.kr.
authors.forename: Yong Rok
authors.initials: YR
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Gandhigram Rural Institute-Deemed University, Gandhigram 624 302, Dindigul District, Tamilnadu, India. Electronic address: mgsethu@gmail.com.
authors.forename: Mathur Gopalakrishnan
authors.initials: MG
authors.lastname: Sethuraman
mesh_terms: D000818:Animals; D001894:Borohydrides; D029421:Cactaceae; D002244:Carbon; D002384:Catalysis; D045744:Cell Line, Tumor; D055772:Green Chemistry Technology / Q000379:methods*; D006801:Humans; D061986:MCF-7 Cells; D008751:Methylene Blue / Q000378:metabolism*; D051379:Mice; D009584:Nitrogen; D010084:Oxidation-Reduction; D010936:Plant Extracts; D045663:Quantum Dots / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D001894:Borohydrides; D010936:Plant Extracts; D002244:Carbon; C025364:sodium borohydride; D009584:Nitrogen; D008751:Methylene Blue
keywords: Catalytic activity; Cytotoxicity; Hydrothermal carbonization; Hylocereus undatus; N-doped carbon dots