IP: 146.185.202.74 On: Sun, 05 May 2019 12:42:31 Copyright: American Scientific Publishers Delivered by Ingenta Copyright © 2019 American Scientific Publishers All rights reserved Printed in the United States of America Article Journal of Nanoscience and Nanotechnology Vol. 19, 5448–5455, 2019 www.aspbs.com/jnn Metal Incorporated g-C 3 N 4 Nanosheets as Potential Cytotoxic Agents for Promoting Free Radical Scavenging in Cancer Cell Lines M. Anto Godwin 1 , K. Mahithashri 1 , O. Jeba Shiney 1 , Madhulika Bhagat 2 , and P. K. Praseetha 1 ∗ 1 Department of Nanotechnology, Noorul Islam Centre for Higher Education, Kumaracoil, Tamil Nadu 629180, India 2 School of Biotechnology, University of Jammu, Jammu Tawi 180006, India Besides numerous advantages, poor penetration, larger size and less efficient nanomaterials are the current challenges in nanomedicine-based therapies. Graphitic carbon nitride (g-C 3 N 4  pos- sesses all the constructive features to overcome the hurdles in cancer therapy. This is a detailed study on the prospects of utilizing g-C 3 N 4 as a therapeutic agent and through this study it has been established that metal incorporations have improved their performance at in vitro levels. g-C 3 N 4 nanomaterial was prepared by simple thermal decomposition process. The synthesized nanosheets were characterized by using UV-visible spectrometer, Fourier transform infrared spec- troscopy (FTIR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermo-gravimetric analysis (TG/DTA). The incorporation of metal particles also has been confirmed by the above mentioned methods. Dose dependent cytotoxicity studies were performed on three different cell lines such as A549, PC-3 and MCF-7. The free rad- ical scavenging activity of g-C 3 N 4 nanosheets was promising using 1,1 ′ -diphenyl-2-picrylhydrazyl (DPPH) assay. Cell scavenging activity of ∼45% with DPPH was observed at 100 l concentra- tions of Ag/g-C 3 N 4 , Zn/g-C 3 N 4 and g-C 3 N 4 . The cytotoxicity and free radical scavenging of cancer cell lines was better with metal incorporated g-C 3 N 4 than their bare counterparts. Hence the study of these thin sheets of nanomaterial is encouraging to be explored as one of the future tools for biomedical therapeutics. Keywords: g-C 3 N 4 , Free Radical Scavenging, Cytotoxicity, Nanosheets, Metal Incorporation. 1. INTRODUCTION In this recent era, nano scale science and engineer- ing gives greatest understanding in the construction and unusual properties of nanostructured material. Particularly it has obtained special attention in their optical, electronic and physiochemical properties. 1 2 Compared to spherical nanoparticles, the two dimensional structures also finds major application in many fields such as optoelectron- ics, protective coatings, heat mirrors, catalyst and biomed- ical applications. 3 4 Control in shape and size of the nanostructures leads to the potential applications such as gas sensing and biomedical theranostics. 5 In addition to these applications, many novel nanomaterials play a major role in the environmental remediation. Better luminescent properties in the 2D layered nanomaterials gives rise to ∗ Author to whom correspondence should be addressed. the bio-imaging possibilities. 6 Though the nanomaterials showcase enhanced properties; the free nanostructures can enter the human body very easily. This influences the health of human beings. 7 8 In these years, graphene holds a powerful position among all carbon-based materials due to their unpredictable structural based optical and electronic properties which opens up better possibilities in all fields for the growth of human life. In that queue, graphitic car- bon nitride (g-C 3 N 4 , is also placing its foot to improve the quality of life with its enhanced properties. g-C 3 N 4 is an allotrope of carbon nitride. It has a layered structure with heptazine units, having amino groups as bridges between them. Comparing with other organic semiconducting mate- rial, g-C 3 N 4 showcases good chemical resistance and good thermal stability. 9 Polymerization process of materials like cyanamide and dicyandiamide helps in the synthesis of g-C 3 N 4 . Since the theoretical study by Liu and Cohen 10 5448 J. Nanosci. Nanotechnol. 2019, Vol. 19, No. 9 1533-4880/2019/19/5448/008 doi:10.1166/jnn.2019.16572