Application of carbon nanomaterials in plant biotechnology Neelofar Majeed b , Kishore C.S. Panigrahi c , Lala Behari Sukla a , Riffat John b , Madhusmita Panigrahy a,⇑ a Siksha ‘O’ Anusandhan deemed to be University, Odisha, 751002, India b University of Kashmir, Srinagar, Jammu & Kashmir, 190006, India c National Institute of Science Education and Research, Odisha, 752050, India article info Article history: Received 12 December 2019 Received in revised form 19 January 2020 Accepted 22 January 2020 Available online xxxx Keywords: Carbon nanotubes Single walled nanotubes Multi walled nanotubes Nanoparticle Plant Biotechnology abstract Carbon nanomaterials are increasingly used in biomedical engineering and medicinal chemistry in recent years due to their unique structural and mechanical properties. Because of their highly tuneable physical properties, carbon nanotubes are most produced for their applicability in electronics, optics, nanomedi- cine, solar cells, high energy efficient renewable energy production, remediation, biosensors for pollu- tants and degradation of contaminants. Application of carbon nanotubes in agriculture and plant research is still a recent development in nanobiotechnology. Despite the potential application of carbon nanotubes for delivering cargo such as proteins, nucleic acids, and drugs for their targeted delivery to cells and organs, inhibition of cell proliferation, induced plasma membrane hyper polarization, oxidative stress in various in vitro mammalian cell studies have raised special concern about their toxicity in ani- mals. This review aims not only to have a brief introduction of types and structures of nanotubes, but also through the detailed descriptions of its applications as biosensors, molecular carriers, in environmental applications, agricultural applications and toxicity issues it will deliver the update knowledge and future perspectives of carbon nano research. Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the National Conference on Trends in Minerals & Materials Technology. Carbon based nanomaterials have been used to understand development and productivity in plants [1–5]. There are of several different types like nanoparticles, nanotubes, nanobeads, nano- horns, fullerenes, nanodiamonds, dots and nanofibres [6–11]. Var- ious carbon nanomaterials that have been used and studied in plants such as carbon nanoparticles (CNPs), single walled carbon nanotubes (SWNT) and multi-walled carbon nanotubes (MWNT) [10,12]. They can affect plant development both positively as well as negatively [10]. 1. Carbon nanotubes – Types and structure Carbon nanotubes (CNT) are particular class of nanomaterials represented by unique physicochemical and structural properties, such as high electrical and thermal conductivity, presence of a hol- low cavity and mechanical strength [13]. Due to such properties CNTs appear as useful agents for biomedical engineering [14], drug-delivery and stimuli responsive cancer theragnostic [15]. CNTs are of two types: multiwalled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) [16]. Structurally, MWNTs are made of many coaxially placed cylinders. Each cylin- der is made up of a single graphene sheet that surrounds a hollow core. MWNTs are having outer diameter in the range of 2–100 nm and inner diameter of 1–3 nm. The length of MWNTs varies up to 1 to several lm [17]. SWNTs are made up of a single graphene cylin- der and their diameter ranges from 0.4 to 2 nm [16,18,19]. On the basis of their helicity and diameter SWNTs can be either metallic or semiconducting [20–22]. In SWNTs, van der Walls forces held together nanotubes which usually occur as hexagonal close- packed bundles. 2. Modification of carbon nanotubes with biological molecules Various biological molecules are engineered both covalently as well as non-covalently to get attached to SWNTs while preserving the functional properties of the biological molecules. One such example of biological molecule is 1-pyrenebutanoic acid succin- imidyl ester, which is non-covalently and irreversibly adsorbed https://doi.org/10.1016/j.matpr.2020.01.618 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and Peer-review under responsibility of the scientific committee of the National Conference on Trends in Minerals & Materials Technology. ⇑ Corresponding author at: Biofuel & Bioprocessing Research Centre, Siksha ‘O’ Anusandhan deemed to be University, Odisha, 751002, India. E-mail addresses: madhusmitapanigrahy@soa.ac.in, mpanigrahy@niser.ac.in (M. Panigrahy). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: N. Majeed, K. C. S. Panigrahi, L. B. Sukla et al., Application of carbon nanomaterials in plant biotechnology, Materials Today: Pro- ceedings, https://doi.org/10.1016/j.matpr.2020.01.618