This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative
Carbon is one of the most abundant elements in nature. Carbonbased nanomaterials have attracted great interest in recent decades. A broad range of carbon nanostructures have been prepared, such as carbon nanotubes, fullerenes, nanofibers, nanodiamond, carbon nanoonions, and other carbonaceous nanomaterials. Carbon nanoparticles have excellent applications because of their unique chemical and physical properties. CNPs can result in a reduction in material weight and in the obtaining of materials with higher impact strength, high surface area per unit volume, electrical conductivity, optical properties, thermal stability, flame resistance, and dimensional stability [
Potential newly found application of carbon nanoparticles occurs in nanoscience nanotechnology in such diverse areas as protective coatings, antimicrobial agents, electronic and optical devices, microsensors, and pollution prevention materials. In biological science carbon based nanomaterials have been utilised as excellent platforms for facilitating biochemical reactions and processes, such as sensitive recognition of antibodies, sequencing of nucleic acids, bioseparation, and biocatalysis [
Due to the emergence of infectious diseases caused by different pathogenic microbes the pharmaceutical companies and the researchers are searching for new antimicrobial agents. Some of antimicrobial agents are extremely irritant and toxic to humans. Thus, the formulation of new effective, resistance-free, low-cost, and natural origin antimicrobial agents is of great interest [
Carbon based nano materials have high antimicrobial activity. It has been established that single-walled CNTs exhibit a strong antimicrobial activity and can pierce bacterial cell walls [
Carbon nanoparticles were isolated from kitchen soot. It is one of the inexpensive, versatile, and reproducible methods for the isolation of carbon nanoparticles. Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. Natural woods such as branches of trees, and coconut husk are used for burning purpose. Glass plates of uniform sizes were hung above the hearth in a chimney so that smoke from this hearth will stick on the glass plate. The glass plates were labelled as
The crude kitchen soot was dissolved in acetone-water (3 : 1) mixture. The undissolved residue was discarded after centrifugation. The clear solution was collected and the solvent was evaporated off on a vacuum rotary evaporator, and the fluorescing CNP in the powder form was collected. The solubility of the nanoparticles was tested and was found to be soluble in acetone, methanol, chloroform, water, DMF, and DMSO.
The characterization techniques included UV/visible spectroscopy, Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) [
1.3 g nutrient broth powder was dissolved in 100 mL water by gently boiling in a 250 mL conical flask stoppered by cotton plug. The broth was sterilized by autoclaving at 15 lbs pressure at 121°C for 15 minutes. It was cooled in a laminar hood, which was disinfected by cleaning thoroughly with absolute alcohol followed by UV irradiation for 20 minutes. A disinfected wire loop size stock microorganisms was transferred into the cold medium under laminar flow. 7.6 g Miller Hinton Agar (M. H. Agar) and 1.2 g Agar Agar were dissolved in 200 mL water in a capped bottle. The agar solution was sterilized by autoclaving at 15 lbs pressure at 121°C for 15 minutes. Then it was cooled to 40–45°C in a laminar hood, which was disinfected by cleaning thoroughly with absolute alcohol followed by UV irradiation for 20 minutes. The medium was then poured into Petri dishes with almost equal agar thickness (2.5 mm). The dishes were cooled for sufficient time to solidify the agar medium. Miller Hinton Agar plates were launed with bacteria using sterile cotton swabs dipped in the nutrient broth culture of bacterial strains. The disc dipped in a solution of carbon nanoparticles was applied in the launed plate. The covered dishes were kept in an incubator oven at 37°C for 24 hr to test. The entire handling was done inside the laminar hood in front of a flame of a spirit lamp. After the test inhibition zone diameter was measured from the clear zone of agar dish. Sterile disc impregnated with solvent as water alone was also used as control [
The carbon nanoparticles obtained were characterized by UV/visible spectroscopy, X-Ray diffraction, and scanning electron microscopy. Carbon nanoparticles were dissolved in acetone-water (3 : 1) mixture and subjected to UV/visible analysis. The spectrum showed peaks at 345 nm and 412 nm are due to various
UV/visible spectrum of carbon nanoparticles.
Scanning electron microscopy was used for surface analysis of the carbon nanoparticles in order to investigate the morphology of the particles that the nanoparticles are irregular in shape, and the nanoparticles occurred in an aggregate structure. The samples were coated with a thin film of platinum to make their surface conducting. The SEM image of the carbon nanoparticle (sample infinity) is shown in Figure
SEM image of carbon nanoparticle.
X-ray crystallography was used as a method of determining the arrangement of atoms within a crystal and also the size of the carbon nanoparticle. The size was found to be 20 nm–40 nm range. The particle size was calculated using Debye-Scherrer formula
XRD pattern of carbon nanoparticles.
The antibacterial activity of isolated carbon nanoparticle was tested by disc diffusion method.
For
The diameter of inhibition zone for
Antibacterial activity of carbon nanoparticles.
Sl. number | Bacterial strain tested | Diameter of zone of | |
---|---|---|---|
inhibition (in mm) | |||
Sample I | Sample II | ||
1 |
|
29 | 28 |
2 |
|
22 | 20 |
3 |
|
20 | 19 |
4 |
|
20 | 21 |
Antibacterial effects of carbon nanoparticles against (a)
Antibacterial effects of carbon nanoparticles against (a)
Carbon nanoparticles were isolated from natural sources such as kitchen soot and characterized by UV/visible spectroscopy, SEM, and XRD. The isolated CNPs were tested against various pathogenic bacteria. The antibacterial properties of carbon nanoparticles collected from natural sources were studied and found to be effective against bacterial strains such as
The authors thank the Department of Science and Technology (Ministry of Science and Technology), Government of India, New Delhi, for financial support by awarding a major research project (no. SR/S1/OC-24/2006, dtd.26.10.2006).