Next Article in Journal
Safety and Local Efficacy of Laser Ablation for the Extrahepatic Metastasis of Hepatocellular Carcinoma: An Available Treatment Strategy
Next Article in Special Issue
Fabrication and Characterization of Antimicrobial Magnetron Cosputtered TiO2/Ag/Cu Composite Coatings
Previous Article in Journal
Nanostructures on Sapphire Surfaces Induced by Metal Impurity Assisted Ion Beam
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Coatings
Volume 10
Issue 10
10.3390/coatings10100950
coatings-logo
Submit to this Journal Review for this Journal Edit a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Synthesis and Antibacterial Aspects of Graphitic C3N4@Polyaniline Composites

by
Mohammad Oves
1,*,
Mohammad Omaish Ansari
2,*,
Reem Darwesh
3,
Afzal Hussian
4,
Mohamed F. Alajmi
4 and
Huda A. Qari
5
1
Center of Excellence in Environmental Studies, King Abdul-Aziz University, Jeddah 21589, Saudi Arabia
2
Center of Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia
3
Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
4
Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
5
Department of Biology, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
*
Authors to whom correspondence should be addressed.
Coatings 2020, 10(10), 950; https://doi.org/10.3390/coatings10100950
Received: 9 September 2020 / Revised: 28 September 2020 / Accepted: 29 September 2020 / Published: 1 October 2020
(This article belongs to the Collection Feature Paper Collection in Surface Coatings for Biomedicine and Bioengineering)
Browse Figures
Versions Notes

Abstract

:
In this work, Pani and [email protected]3N4 was synthesized by in situ oxidative polymerization methodology of aniline, in the presence of g-C3N4. The as prepared [email protected]3N4 was characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction (XRD). The morphological analysis showed well dispersed Pani in g-C3N4, as well as the coating of Pani on g-C3N4. The XRD further revealed this, and peaks of Pani as well as g-C3N4 was observed, thereby suggesting successful synthesis of the composite. The DC electrical conductivity studies under isothermal and cyclic aging conditions showed high stability of composites over 100 °C. Further, the synthesized composite material proved to be an excellent antimicrobial agent against both type i.e., gram positive Streptococcus pneumoniae and negative bacteria Escherichia coli. In the zone inhibition assay 18 ± 0.5, 16 ± 0.75 and 20 ± 0.5, 22 ± 0.5 mm zone diameter were found against E. coli and S. pneumoniae in presence of pure g-C3N4 and [email protected]3N4 at 50 µg concentrations, respectively. Further antimicrobial activity in the presence of sunlight in aqueous medium showed that [email protected]3N4 is more potent than pure g-C3N4.

1. Introduction

With the publication of 1977 chemical communication paper by the eminent scientists’ Alan J. Heeger, Alan G. MacDiarmid and Hideki Shirakawa, a new dynamic field of conducting polymers was brought into limelight [1]. Later with the discovery or utilization of other polymers such as polyaniline (Pani), polypyrrole, polythiophene, para phenylene derivatives etc., the research in this field grew by leaps and bounds. With the advent of time, the conducting polymers entered into various fields such as sensors, energy storage devices, antimicrobial materials, adsorbents for pollutants, etc. [2,3,4,5].
Among different conducting polymers, Pani has been widely used due to its properties such as: low cost of monomers, ease of polymerization, long shelf life, acid-base doping characteristics, etc. [6]. Pani has mainly been used as an antimicrobial agent against bacteria, fungi etc. [7,8]. Dhivya et al. [4] showed that the non-conduction emeraldine base of Pani is less effective against various gram-negative, gram-positive bacteria and fungus Candida albicans than emeraldine salt of Pani. They interpreted that Pani binds with the cell wall and afterward, the dopant ions react with the cell, components thereby resulting in the lysis of cells. Similarly, Poyraz et al. [8] showed that Pani acts as an excellent matrix to hold silver and the composite was found to be highly effective in inhibiting the growth of Escherichia coli and Gram-positive Staphylococcus pneumoniae. Similarly, a lot of other workers have also used Pani composites successfully as antimicrobial agents [9,10,11]. Thus, it is established that Pani, in combination with other nanomaterials, can prove to be more lethal towards microbial growth due to the synergistic or additional effect.
Recently carbon-based materials have been widely explored for a large number of promising applications [12,13]. Among these, graphitic carbon nitride (g-C3N4) has shown promising antimicrobial properties in combination with graphene-based materials, silver etc. [14,15,16,17]. The photoactivity of g-C3N4 makes its suitable material for visible light assisted disinfection of microbial [18]. Based on the light adsorption and conductive properties of Pani along with good antimicrobial properties of g-C3N4, it is expected that their composites may show high microbial disinfection activity than the pure counterparts due to the synergism between the constituents. As the microbial activity is said to be related to the electrical conductivity which can mediate contact with the negatively charged bacterial cell surface through electrostatic adherence [19]. Thus the study of conductivity and its stability is also a factor for Pani based antimicrobial composites [20,21]. In previous studies, g-C3N4 composite material showed bactericidal activity against E. coli in aqueous medium under visible light illumination [22]. The bactericidal mechanism revealed the formation of light-induced holes on the g-C3N4 surface. A similar bactericidal phenomenon was also observed by applying a single layer of g-C3N4 with photo-irradiation against E. coli [23]. Murugesan et al. [24] showed that the composite of silver iodide anchored on g-C3N4 could prove to be an effective platform for the growth inhibition of bacteria. On further investigation, it was observed that the Ag/g-C3N4 hybrid could interact with the bacterial DNA and disturb the bacterial metabolic process.
A lot of work has been reported till date on the photocatalytic degradation of pollutants by variety of synthesized photocatalyst [25]. However, photocatalytic destruction of microorganism which also operates by similar mechanism has been poorly reported in literatures [26]. Thus, it is significant to develop light driven efficient photocatalysts for microbial destruction. This research provides new research horizons towards the use of metal-free catalysts for remarkably increased efficiency in the bacteria photoinactivation.
Thus, in this work, the composites of Pani with g-C3N4 was synthesized by in-situ oxidative polymerization of aniline with g-C3N4. The as-prepared composite was studied for its electrical conductivity properties by two aging techniques i.e., by cyclic aging conditions and isothermal aging conditions. Finally, the antibacterial properties of the composites were tested against the E. coli and S. pneumoniae and [email protected] g-C3N4 showed a much-enhanced effect than pure g-C3N4. Thus g-C3N4 based conducting polymer composites can be exciting new future materials for the disinfection of a wide variety of microorganisms.

2. Experimental

2.1. Materials

Aniline from E-Merck India Ltd. was purified by distilling under reduced pressure before use. Potassium persulphate, HCl, ethanol, melamine and Dimethyl sulfoxide (DMSO) were purchased from Sigma Aldrich and were used as received. The de-ionized water used in these experiments was obtained from a PURE ROUP 30 water purification system. Culture media nutrient broth and Agar powder was purchased from the HiMedia (Pvt. Ltd., Mumbai, India)
The culture media, solvents, antimicrobial agents, control strains and apparatus are required for the determination of minimal inhibitory concentration (MIC) test. The test was performed using Mueller-Hinton Agar (MHA), which is the most common medium for routine susceptibility tests because it has good reproducibility and gives satisfactory growth of most bacterial pathogens. All bacterial inoculum were prepared in as heart infusion broth (HIB).

2.2. Methods and Studies

The X-ray diffraction (XRD) data were recorded with a RIGAKU-ULTIMA IV (The Woodlands, Texas, USA ) with Cu Ka radiation at 1.540 Å in the range of 10 to 90 2θ at 40 kV. To study the chemical composition of the samples, X-ray photoelectron spectroscopy (XPS, New York City NY, United States) (ESCALAB 250 equipped with an Al-Ka (1486.6 eV)) with a power of 50 W and operating voltage of 1 kV was used. The surface morphological analysis was performed by field-emission scanning electron microscopy (JSM-7500F of JEOL (Tokyo, Japan) and transmission electron microscopy (FE-TEM, Tecnai G2 F20, FEI, Hillsboro, OR, USA). The DC electrical conductivity measurement under cyclic aging conditions was done using a 4-in-line probe electrical conductivity measuring instrument with a PID controlled oven (Scientific Equipments, Roorkee, India). For cyclic studies, the electrical conductivity was recorded on subsequent heating and cooling cycles from 40–150 °C, while in the isothermal stability studies, the samples were subjected to 50, 70, 90, 110 and 130 °C for 30 min and the conductivity was recorded at an interval of every 10 min. The calculation of electrical conductivity can be seen elsewhere [27].

2.3. Bacterial Disinfectant Studies of [email protected]

2.3.1. Bacterial Inoculum Preparation

The pure bacterial culture of E. coli and S. pneumoniae was grown up to 16 h from the bacterial culture and was picked from the single isolated colony from the cultured medium plate. Further subculture was done in a tube with 3 mL BHI containing 0.3% yeast extract and 2% NaCl. The tube was shaken vigorously in a water bath at 30 °C until it achieved or exceeded the turbidity of 0.5 MacFarland standard (prepared by adding 0.5 mL of 0.048 M BaCl2 to 99.5 mL of 0.36 NH2SO4; commercially available). The inoculum may likewise be standardized based on optical thickness (1 cm light path in a cuvette at 625 nm OD upto 0.08–0.1) utilizing a spectrophotometer. It is generally accomplished in 24 h and the standardized inoculum has a concentration of 1 × 108 cfu/mL. The standardized inoculum was diluted 1:10 in sterile normal saline solution to obtain the desired concentration of 106 cfu/mL and subsequently, 0.1 mL of it was taken out with the help of a pipette and transferred to well.

2.3.2. Bacterial Disinfectant [email protected]3N4 Stock Solution Preparation

The synthesized [email protected]3N4 for testing as an antimicrobial agent, immediately after synthesis was stored in the refrigerator and before experimentation (opening the cap of tubes) it was taken out to attain room temperature. The [email protected]3N4 dispersion was made by dissolving 1.0 g of it in 1 mL DMSO in order to attain a concentration of 1000 μg/mL.

2.3.3. Media Plates Preparation for Antimicrobial Assessment

The sterile petri plate was used in order to categorize the antimicrobial agent and their dose from 0 to 100 µg/mL. The petri dish was labeled on the upper portion of the bottom side in order to ensure that the plate is inserted at the correct point of the inoculating apparatus. In order to locate each bacterial strain in a well, on a reference paper, a scheme was drawn that was used to read the results. Then 1 mL of appropriate dilutions of the test antimicrobial agent was put into the labelled plate by pipette and two replicates was made for each concentration. Later 9 mL of MHA (at 48–50 °C), was added into the plate with the appropriate dilution of the test antimicrobial agent and mixed thoroughly. The agar was allowed to solidify at room temperature and the plates was used immediately after the agar surface dried completely. If necessary, the surface of agar was dried in a laminar flow chamber under UV light, but excessive drying was avoided. The inoculated agar plates was kept at room temperature until the moisture in the inoculum spot was absorbed by the agar and all the spots were dry. The plates were incubated in an inverted position at 30 °C for 24 h and after which the inoculated plate was placed on or beside the reference paper in order to identify the spot or position of each tested bacteria. The MIC was recorded at the lowest concentration of antimicrobial agent that completely inhibits the growth of the bacteria as detected by the naked eye. The control agar plates were also prepared by pipetting 10 mL of MHA into a sterile petri dish in the absence of any antimicrobial agent. In this study, the agar dilution technique was used to qualitatively measure the in vitro activity of an antimicrobial agent i.e., [email protected]3N4, against the test bacteria. In this method, the required amounts of [email protected]3N4 was amended in agar plates and inoculated in spots with the test microorganisms under study.

2.3.4. Zone Inhibition Assay

The modified method of the Kirby-Bauer disk diffusion susceptibility test was used to determine the sensitivity or resistance of gram-positive and negative pathogenic bacteria to [email protected]3N4. Briefly, the test strains of pathogenic bacteria were grown on Mueller-Hinton agar in the presence of different doses of [email protected]3N4 impregnated on the filter paper disks. The presence or absence of growth around the disks is an indirect measure of the ability of that compound to inhibit the growth of that organism. A 6-mm filter paper disk impregnated with a 10, 20, 40, 80 and 100 µg/disc of [email protected]3N4 were placed on a Mueller-Hinton (MH) agar plate, immediately after the inoculation of bacterial inoculum was absorbed into the plates. Here applied composite material PANI/g-C3N4 begun to diffuse into the surrounding agar as an antimicrobial agent. The rate of diffusion of the antimicrobial through the agar is dependent on the diffusion and solubility properties of the drug in MH agar and the molecular weight of the antimicrobial compound.

2.3.5. Bacterial Viability Assay in Light and Dark Incubation

The estimation of the viability of a bacterial culture is valuable for several environmental and medical aspects. The determination of critical threshold amount of [email protected]3N4 which affects the bacterial growth is highly useful in systematically developing the knowledge antimicrobial material. For this, variable dose treatment (0–100 µg/mL) in 5 mL culture tubes containing 1 × 106 cfu/mL was exposed to eight hours of light and eight hours in dark incubation. For confirmation of effect of treatment and light effect on bacterial cells, 0.1 ml aliquots was spread on the nutrient agar plate and incubated overnight to calculate the growing colony on the media. After overnight incubation, the bacterial growth on plate was observed and calculated. For scanning electron microscopy analysis at sub MIC concentration (50 µg/mL) growing culture was selected for the study. From each culture, 1 mL sample was centrifuged at 10,000 rpm, subsequently washed three times with phosphate saline buffer and then fixed with 2.5% glutaraldehyde at 4 °C for 8 h. After this, it was washed with 10, 20 and 30% ethanol and after that, final washing was done with Milli Q water. Each sample was attached to the grid using carbon tape and sputtered with gold layer by means of sputter coater (Quorum Q150R ES, Quorum Technologies Ltd. Ashford, Kent, UK).

2.4. Synthesis of g-C3N4 and [email protected]3N4 Nanocomposite

The g-C3N4 was synthesized from melamine by employing the methodology as reported in our earlier studies [28]. [email protected]3N4 was synthesized by insitu oxidative polymerization of aniline in the presence of g-C3N4. In a typical process 0.5 gm of g-C3N4 was dispersed in 200 mL of 1 M HCl and to which 1 mL of aniline was added under vigorous stirring conditions. To the above dispersion of g-C3N4 and aniline the solution of oxidant (1.48 g of Potassium persulphate in 200 mL of 1 M HCl) was added slowly to initiate polymerization. The entire setup was put under slow stirring for 24 h, after which the solution was filtered, washed with excess of water and ethanol and subsequently dedoped with ammonia solution. Thus prepared emeraldine base of [email protected]3N4 was washed again with excess of water and ethanol and finally doped with 1 M HCl. Thus prepared [email protected]3N4 nanocomposite was filtered and dried at 80 °C for 12 h and stored in desiccator for further studies.

3. Results and Discussion

3.1. Scanning Electron Microscopy

The SEM image of g-C3N4 shows a large number of strongly or loosely aggregated sheets of various sizes (Figure 1a–d). Several small particles like structure or a large number of pores on the surface are due to the gas discharge during the melamine decomposition, which resulted in the breakage of sheets and its porosity [29]. In the case of [email protected]3N4, surface coating of Pani occurred on g-C3N4, thereby giving g-C3N4 sheets a rough appearance and high functionality. Apart from these, tubular Pani is seen spread throughout as well as sticking or embedded in the g-C3N4 matrix. The TEM images of [email protected]3N4 shows the presence of g-C3N4 sheets of large dimensions. At higher magnification, Pani tubes dispersed between the sheets as well as some Pani coated on the surface can be evidently seen (Figure 2a–c).

3.2. X-ray Diffraction

The XRD of g-C3N4 and [email protected]C3N4 is presented in Figure 3. The XRD pattern of the synthesized g-C3N4 shows two prominent peaks at 13.2 and 27.3 2θ, which corresponds to the (100) and (002) planes of g-C3N4. The most substantial peak at 27.3 2θ is close to the peak position of graphite (002), and is due to the interlayer stacking of the conjugated aromatic systems. The small-angle peak at 13.2 2θ is associated with interlayer stacking of the tris-s-triazine unit [30]. In the case of [email protected]3N4 several small peaks of Pani at ~9, 15, 20.5 2θ were observed and two large peaks at 25.6 and 27.7 2θ were observed. The noticeable difference is the reduction in the intensity of the peak in the composite, which is due to the presence of amorphous Pani as well as due to the coating of Pani on g-C3N4. Similar reduction of peak intensity has been observed for other nanomaterials on interaction with Pani [25,27].

3.3. DC Electrical Conductivity

The electrical conductivity of as-synthesized [email protected]3N4 at room temperature was measured to be 4.4 S/cm. After annealing the sample, the conductivity dropped to ~1.70 S/cm, which might be due to loss of dopant, water molecules, impurities etc. The DC electrical conductivity retention of [email protected]3N4 by cyclic aging studies showed an increase in electrical conductivity in each cycle. The initial conductivity dropped to lower values on each cycle, thereafter followed a rise along with the rise in temperature. It can be observed that the increase in conductivity is more uniform in the 4th and 5th cycles, which suggests that the material on subsequent annealing showed semiconducting behavior. Apart from this, in contrast to previously reported Pani based composites, here, [email protected]3N4 showed a slight dip in electrical conductivity after 100 °C, which might be due to highly stable g-C3N4 incorporated inside [27]. The electrical conductivity under isothermal aging conditions also showed similar behavior and stable reading were observed at 50, 70 and 90 °C; however, a dip in electrical conductivity was observed at 110 and 130 °C (Figure 4). The drop in the electrical conductivity is due to the loss of dopant, water molecules, impurities, degradation of polymer chains, etc. as mentioned above [31].

3.4. Antimicrobial Assessment

The antimicrobial assessment of g-C3N4 and [email protected]3N4 showed high growth inhibition against E. coli and S. pneumoniae on Petri plate which was previously amended with a specific amount of dose from 0 to 100 µg/mL. The E. coli growth pattern significantly diminished when applied concentration in plate was more than 75 and 60 µg/mL of g-C3N4 and [email protected]3N4, respectively. Similarly, S. pneumoniae growth disappeared at 100 µg/mL and 60 of g-C3N4 and [email protected]3N4, respectively, during the spot inoculation of test strain. The appearance and amount of bacterial growth on the plates depict the resistance towards g-C3N4 or [email protected]3N4. The bacterial growth inhibition at the minimum or lowest concentration of composite material as an antimicrobial agent is regarded as the endpoint. Similar conclusions were made previously on Pani based chemical sensor fabrication studies [32,33,34,35].

3.4.1. Zone Inhibition Assay

This study determined the antibacterial potential of g-C3N4 and [email protected]3N4 and the resistance pattern of gram-positive and negative pathogenic bacteria. The filter paper impregnated disk with different doses of [email protected]3N4 when placed on a media plate after inoculation showed excellent activity against test strain. After overnight incubation, the zone inhibition of 14 and 16 mm was found against the E. coli, and 15 and 18 mm zone inhibition size was found against the S. pneumoniae with 100 µg dose/disks of g-C3N4 and [email protected]3N4 applied separately (Table 1). The rate of diffusion of the antimicrobial through that the agar is dependent on the diffusion and solubility properties of the drug in agar media and the molecular weight of the antimicrobial compound. Larger molecules will diffuse at a slower rate than lower molecular weight compounds. These factors, in combination, result in antimicrobial activity having a unique breakpoint zone size indicating susceptibility to that antimicrobial compound. If the agar plate has been inoculated with a suspension of the pathogen to be tested prior to the placing of disks on the agar surface, the simultaneous growth of the bacteria and diffusion of the antimicrobial compounds occurs. Growth occurs in the presence of an antimicrobial compound when the bacteria reach a critical mass and can overpower the inhibitory effects of the antimicrobial compound. The estimated time of a bacterial suspension to reach critical mass is 8 to 10 h for most commonly recovered pathogens, but is characteristic of each species, and influenced by the media and incubation temperature. The size of the zone of inhibition of growth is influenced by the depth of the agar, since the antimicrobial diffuses in three dimensions; thus a shallow layer of agar will produce a larger zone of inhibition than a deeper layer. The point at which critical mass is reached is demonstrated by a sharply marginated circle of bacterial growth around the disk. The concentration of antimicrobial compound at this margin is called the critical concentration and is approximately equal to the minimum inhibitory concentration obtained in broth dilution susceptibility tests.

3.4.2. Photocatalysis Effect on Bacterial Viability

The effect of the compound in the presence of sunlight on the bacterial cell survival was checked in cfu/mL after 8 h exposure in light and dark incubation separately. Further bacterial growth patterns were confirmed by treating the sample 0.1 mL aliquots spread on the media plate subsequently incubated overnight and the appeared colony on the media has noted with significant positive results. The antibacterial activity of g-C3N4 significantly increased upto 33% in E. coli and 25% in S. pneumoniae when samples was exposed to sunlight (Table 2). While for samples treated with [email protected]3N4 in sunlight the antibacterial activity was 50 and 58% against E. coli and S. pneumoniae, respectively (figure bacteria Sem). Overall it was concluded that the antibacterial activity of g-C3N4 and [email protected]3N4 was significantly enhanced on being exposed to sunlight. Similarly, effect of photocatalysis on the bacterial diversity was observed previously [36,37]. The photoinactivation of E. coli and S. pneumoniae by g-C3N4 [email protected]3N4 thin film can be explained by first adsorption of g-C3N4 [email protected]3N4 to the negatively charged bacterial cell surface through electrostatic adherence. The absorption of visible light by g-C3N4 and [email protected]3N4 produces e−/h+ pairs. The e−/h+ pairs by a series of reactions generates OH radical which are responsible for the photoinactivation of bacterial. Firstly, the radicals damage the surfaces of the bacterial cells leading to the leaking of internal components through the damaged sites which eventually leads to the death of bacterial cells [38]. This is evident from the SEM micrographs as shown in Figure 5.

4. Conclusions

In summary, the successful synthesis of [email protected]3N4 composites has been achieved by simple in-situ oxidative polymerization of aniline along with g-C3N4. The coating of Pani on g-C3N4 was confirmed by SEM and TEM, which suggested strong interaction between them. [email protected]3N4 showed high DC electrical conductivity retention at elevated temperatures under isothermal and cyclic aging conditions, which might be due to highly stable g-C3N4, thereby resisting the degradation of Pani, by dissipating heat, synergistic effect etc. Furthermore, the excellent antimicrobial activity of [email protected]3N4 when applied in the presence of sunlight against the indicator organism E. coli and pathogenic bacterial strain of Streptococcus pneumoniae suggested its applications towards environmental remediation applications.

Author Contributions

Conceptualization, M.O. and M.O.A.; methodology, M.O. and M.O.A.; software, R.D.; validation, A.H., M.F.A. and H.A.Q.; formal analysis, A.H.; investigation, M.O.; resources, M.O.A.; data curation, M.O.; writing—original draft preparation, M.O. and M.O.A.; writing—review and editing, A.H.; visualization, H.A.Q.; supervision, M.O.A.; project administration, A.H.; funding acquisition, M.F.A. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Acknowledgments

The authors greatly acknowledge to the Centre of Excellence environmental studies and Center of Nanotechnology, King Abdulaziz University, Jeddah, Makkah, KSA. The authors also greatly acknowledge the generous support from Researchers Supporting Project number (RSP-2020-122), King Saud University, Riyadh, Saudi Arabia.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Shirakawa, H.; Louis, E.J.; MacDiarmid, A.G.; Chiang, C.K.; Heeger, A.J. Synthesis of electrically conducting organic polymers: Halogen derivatives of polyacetylene, (CH)x. J. Chem. Soc. Chem. Commun. 1977, 578–580. [Google Scholar] [CrossRef]
  2. Ansari, M.O.; Mohammad, F. Thermal stability, electrical conductivity and ammonia sensing studies on p-toluenesulfonic acid doped polyaniline:titanium dioxide (pTSA/Pani:TiO2) nanocomposites. Sens. Actuators B-Chem. 2011, 157, 122–129. [Google Scholar] [CrossRef]
  3. Ansari, M.O.; Kumar, R.; Ansari, S.A.; Ansari, S.P.; Barakat, M.A.; Alshahrie, A.; Cho, M.H. Anion selective pTSA doped [email protected] oxide-multiwalled carbon nanotube composite for Cr(VI) and Congo red adsorption. J. Colloid Interface Sci. 2017, 496, 407–415. [Google Scholar] [CrossRef] [PubMed]
  4. Dhivya, C.; Vandarkuzhali, S.A.A.; Radha, N. Antimicrobial activities of nanostructured polyanilines doped with aromatic nitro compounds. Arab. J. Chem. 2019, 12, 3785–3798. [Google Scholar] [CrossRef][Green Version]
  5. Kumar, R.; Ansari, M.O.; Alshahrie, A.; Darwesh, R.; Parveen, N.; Yadav, S.K.; Barakat, M.A.; Cho, M.H. Adsorption modeling and mechanistic insight of hazardous chromium on para toluene sulfonic acid [email protected] nanocomposites. J. Saudi Chem. Soc. 2019, 23, 188–197. [Google Scholar] [CrossRef]
  6. Ansari, M.O.; Oves, M.; Salah, N.; Asad, M.; Kumar, R.; Hasan, P.M.Z.; Alshahrie, A.; Darwesh, R. DC electrical conductivity retention and antibacterial aspects of microwave-assisted ultrathin [email protected] composite. Chem. Pap. 2020, 74, 3887–3898. [Google Scholar] [CrossRef]
  7. Ahmad, N.; Sultana, S.; Kumar, G.; Zuhaib, M.; Sabir, S.; Khan, M.Z. Polyaniline based hybrid bionanocomposites with enhanced visible light photocatalytic activity and antifungal activity. J. Environ. Chem. Eng. 2019, 7, 102804. [Google Scholar] [CrossRef]
  8. Poyraz, S.; Cerkez, I.; Huang, T.S.; Liu, Z.; Kang, L.; Luo, J.; Zhang, X. One-step Synthesis and Characterization of Polyaniline Nanofiber/Silver Nanoparticle Composite Networks as Anti-bacterial Agents. ACS Appl. Mater. Interface 2014, 6, 20025–20034. [Google Scholar] [CrossRef]
  9. Farias, E.A.O.; Dionisio, N.A.; Quelemes, P.V.; Sergio, H.L.; José, M.E.M.; Edson, C.S.F.; Ivan, H.B.; José Roberto, S.A.L.; Carla, E. Development and characterization of multilayer films of polyaniline, titanium dioxide and CTAB for potential antimicrobial applications. Mater. Sci. Eng. C 2014, 35, 449–454. [Google Scholar] [CrossRef]
  10. Hussein, M.A.; El-Shishtawy, R.M.; Alamry, K.A.; Asiri, A.M.; Mohamed, S.A. Efficient water disinfection using hybrid polyaniline/graphene/carbon nanotube nanocomposites. Environ. Technol. 2019, 40, 2813–2824. [Google Scholar] [CrossRef]
  11. Mohsen, R.M.; Morsi, S.M.M.; Selim, M.M.; Ghoneim, A.M.; El-Sherif, H.M. Electrical, thermal, morphological, and antibacterial studies of synthesized polyaniline/zinc oxide nanocomposites. Polym. Bull. 2019, 76, 1–21. [Google Scholar] [CrossRef]
  12. Almoisheer, N.; Alseroury, F.A.; Kumar, R.; Almeelbi, T.; Barakat, M.A. Synthesis of Graphene Oxide/Silica/Carbon Nanotubes Composite for Removal of Dyes from Wastewater. Earth Syst. Environ. 2019, 3, 651–659. [Google Scholar] [CrossRef]
  13. Kumar, R.; Laskar, M.A.; Hewaidy, I.F.; Barakat, M.A. Modified Adsorbents for Removal of Heavy Metals from Aqueous Environment: A Review. Earth Syst. Environ. 2019, 3, 83–93. [Google Scholar] [CrossRef]
  14. Liu, C.; Wang, L.; Xu, H.; Wang, S.; Gao, S.; Ji, X.; Xu, Q.; Lan, W. “One pot” green synthesis and the antibacterial activity of g-C3N4/Ag nanocomposites. Mater. Lett. 2016, 164, 567–570. [Google Scholar] [CrossRef]
  15. Sun, L.; Du, T.; Hu, C.; Chen, J.; Lu, J.; Lu, Z.; Han, H. Antibacterial Activity of Graphene Oxide/g-C3N4 Composite through Photocatalytic Disinfection under Visible Light. ACS Sustain. Chem. Eng. 2017, 5, 8693–8701. [Google Scholar] [CrossRef]
  16. Qamar, M.A.; Shahid, S.; Javed, M.; Iqbal, S.; Sher, M.; Akbar, M.B. Highly efficient g-C3N4/Cr-ZnO nanocomposites with superior photocatalytic and antibacterial activity. J. Photochem. Photobiol. Chem. 2020, 401, 112776. [Google Scholar] [CrossRef]
  17. Thakur, D.; Ta, Q.T.H.; Noh, J.S. Photon-Induced Superior Antibacterial Activity of Palladium-Decorated, Magnetically Separable Fe3O4/Pd/mpg-C3N4 Nanocomposites. Molecules 2019, 24, 3888. [Google Scholar] [CrossRef][Green Version]
  18. Ngullie, R.C.; Alaswad, S.O.; Bhuvaneswari, K.; Shanmugam, P.; Pazhanivel, T.; Arunachalam, P. Synthesis and Characterization of Efficient ZnO/g-C3N4 Nanocomposites Photocatalyst for Photocatalytic Degradation of Methylene Blue. Coatings 2020, 10, 500. [Google Scholar] [CrossRef]
  19. Robertson, J.; Nikolaidis, M.G.; Nieuwoudt, M.K.; Swift, S. The antimicrobial action of polyaniline involves production of oxidative stress while functionalisation of polyaniline introduces additional mechanisms. PeerJ 2018, 6, e5135. [Google Scholar] [CrossRef]
  20. Nikolaidis, M.R.G.; Bennett, J.R.; Swift, S.; Easteal, A.J.; Ambrose, M. Broad spectrum antimicrobial activity of functionalized polyanilines. Acta Biomater. 2011, 2, 4204–4209. [Google Scholar] [CrossRef]
  21. Zengin, H.; Aksin, G.; Zengin, G.; Kahraman, M.; Kilic, I.H. Preparation and Characterization of Conductive Polyaniline/Silver Nanocomposite Films and Their Antimicrobial Studies. Polym. Eng. Sci. 2019, 59, E182–E194. [Google Scholar] [CrossRef]
  22. Huang, J.; Ho, W.; Wang, X. Metal-free disinfection effects induced by graphitic carbon nitride polymers under visible light illumination. Chem. Comm. 2014, 50, 4338–4340. [Google Scholar] [CrossRef] [PubMed]
  23. Zhao, H.; Yu, H.; Quan, X.; Chen, S.; Zhang, Y.; Zhao, H.; Wang, H. Fabrication of atomic single layer graphitic-C3N4 and its high performance of photocatalytic disinfection under visible light irradiation. Appl. Catal. B Environ. 2014, 152, 46–50. [Google Scholar] [CrossRef]
  24. Murugesan, P.; Narayanan, S.; Matheswaran, M. Photocatalytic performance and antibacterial activity of visible light driven silver iodide anchored on Graphitic-C3N4 binary composite. Environ. Nanotechnol. Monit. Manag. 2018, 10, 253–263. [Google Scholar] [CrossRef]
  25. Kumar, R.; Barakat, M.A.; Alseroury, F.A. Oxidized g-C3N4/polyaniline nanofiber composite for the selective removal of hexavalent chromium. Sci. Rep. 2017, 7, 1–11. [Google Scholar] [CrossRef] [PubMed]
  26. Barakat, M.A.; Anjum, M.; Kumar, R.; Alafif, Z.; Oves, M.; Ansari, M.O. Design of ternary Ni(OH)2/graphene oxide/TiO2 nanocomposite for enhanced photocatalytic degradation of organic, microbial contaminants, and aerobic digestion of dairy wastewater. J. Clean. Prod. 2020, 258, 120588. [Google Scholar] [CrossRef]
  27. Ansari, M.O.; Mohammad, F. Thermal stability of HCl-doped-polyaniline and TiO2 nanoparticles-based nanocomposites. J. Appl. Polym. Sci. 2012, 124, 4433–4442. [Google Scholar] [CrossRef]
  28. Alshahrie, A.; Ansari, M.O. High Performance Supercapacitor Applications and DC Electrical Conductivity Retention on Surfactant Immobilized Macroporous Ternary Polypyrrole/[email protected] Nanocomposite. Electron. Mater. Lett. 2019, 15, 238–246. [Google Scholar] [CrossRef]
  29. Yuan, X.; Zhou, C.; Jing, Q.; Tang, Q.; Mu, Y.; Du, A. Facile Synthesis of g-C3N4 Nanosheets/ZnO Nanocomposites with Enhanced Photocatalytic Activity in Reduction of Aqueous Chromium(VI) under Visible Light. Nanomaterials 2016, 6, 173. [Google Scholar] [CrossRef][Green Version]
  30. Tahir, M.; Cao, C.; Butt, F.K.; Butt, S.; Idrees, F.; Ali, Z.; Aslam, I.; Tanveer, M.; Mahmood, A.; Mahmood, N. Large scale production of novel g-C3N4 micro strings with high surface area and versatile photodegradation ability. CrystEngComm 2014, 16, 1825–1830. [Google Scholar] [CrossRef][Green Version]
  31. Ansari, M.O.; Kumar, R.; Alshahrie, A.; Abdel-wahab, M.S.; Sajith, V.K.; Ansari, M.S.; Jilani, A.; Barakat, M.A.; Darwesh, R. CuO sputtered flexible [email protected] thin films:A recyclable photocatalyst with enhanced electrical properties. Compos. B Eng. 2019, 175, 107092. [Google Scholar] [CrossRef]
  32. Oves, M.; Shahadat, M.; Ansari, S.A.; Aslam, M.; Ismail, I.I.M. Polyaniline Nanocomposite Materials for Biosensor Designing, Electrically Conductive Polymer and Polymer Composites. In Book Synthesis to Biomedical Applications; Khan, A., Jawaid, M., Khan, A.A.P., Asiri, A.M., Eds.; Wiley-VCH Verlag: Weinheim, Germany, 2018; pp. 113–135. [Google Scholar]
  33. Khan, A.A.P.; Khan, A.; Rahman, M.M.; Asiri, A.M.; Oves, M. Chemical sensor development and antibacterial activities based on polyaniline/gemini surfactants for environmental safety. J. Polym. Environ. 2018, 26, 1673–1684. [Google Scholar] [CrossRef]
  34. Thakur, B.; Amarnath, C.A.; Mangoli, S.H.; Sawant, S.N. Polyaniline nanoparticle based colorimetric sensor for monitoring bacterial growth. Sens. Actuators B Chem. 2015, 207, 262–268. [Google Scholar] [CrossRef]
  35. Bushra, R.; Shahadat, M.; Ahmad, A.; Nabi, S.A.; Umar, K.; Oves, M.; Raeissi, A.S.; Muneer, M. Synthesis, characterization, antimicrobial activity and applications of polyanilineTi (IV) arsenophosphate adsorbent for the analysis of organic and inorganic pollutants. J. Hazard. Mater. 2014, 264, 481–489. [Google Scholar] [CrossRef] [PubMed]
  36. Faraji, M.; Mohaghegh, N.; Abedini, A. Ternary composite of TiO2 nanotubes/Ti plates modified by g-C3N4 and SnO2 with enhanced photocatalytic activity for enhancing antibacterial and photocatalytic activity. J. Photochem. Photobiol. B Biol. 2018, 178, 124–132. [Google Scholar] [CrossRef] [PubMed]
  37. Bushra, R.; Arfin, T.; Oves, M.; Raza, W.; Mohammad, F.; Khan, M.A.; Ahmad, A.; Ameer, A.; Muneer, M. Development of PANI/MWCNTs decorated with cobalt oxide nanoparticles towards multiple electrochemical, photocatalytic and biomedical application sites. New J. Chem. 2016, 40, 9448–9459. [Google Scholar] [CrossRef]
  38. Koli, V.B.; Delekar, S.D.; Pawar, S.H. Photoinactivation of bacteria by using Fe-doped TiO2-MWCNTs nanocomposites. J. Mater. Sci. Mater. Med. 2016, 27, 177. [Google Scholar] [CrossRef]
Coatings 10 00950 g001 550
Figure 1. SEM micrographs of g-C3N4 (a,b) and [email protected]3N4 (c,d) at different magnifications ((a,c) is at 30,000× and (b,d) is at 60,000× magnification).
Figure 1. SEM micrographs of g-C3N4 (a,b) and [email protected]3N4 (c,d) at different magnifications ((a,c) is at 30,000× and (b,d) is at 60,000× magnification).
Coatings 10 00950 g001
Coatings 10 00950 g002 550
Figure 2. TEM micrographs of [email protected]3N4 (a–c) at different magnifications.
Figure 2. TEM micrographs of [email protected]3N4 (a–c) at different magnifications.
Coatings 10 00950 g002
Coatings 10 00950 g003 550
Figure 3. XRD pattern of g-C3N4 and [email protected]3N4.
Figure 3. XRD pattern of g-C3N4 and [email protected]3N4.
Coatings 10 00950 g003
Coatings 10 00950 g004 550
Figure 4. DC electricity conductivity retention by cyclic (a) and isothermal aging studies of [email protected]3N4 (b).
Figure 4. DC electricity conductivity retention by cyclic (a) and isothermal aging studies of [email protected]3N4 (b).
Coatings 10 00950 g004
Coatings 10 00950 g005 550
Figure 5. The effect of g-C3N4 and [email protected]3N4 on E. coli and S. pneumoniae cells structure in dark and sunlight. The micrographs labeled (a) and (f) are control E. coli and S. pneumoniae respectively; (b) and (g) are g-C3N4 treated E. coli and S. pneumoniae in dark respectively; (c) and (h) are g-C3N4 treated E. coli and S. pneumoniae in sunlight respectively; (d) and (i) are [email protected]3N4 treated E. coli and S. pneumoniae in dark respectively while (e) and (j) are [email protected]3N4 treated E. coli and S. pneumoniae in sunlight respectively.
Figure 5. The effect of g-C3N4 and [email protected]3N4 on E. coli and S. pneumoniae cells structure in dark and sunlight. The micrographs labeled (a) and (f) are control E. coli and S. pneumoniae respectively; (b) and (g) are g-C3N4 treated E. coli and S. pneumoniae in dark respectively; (c) and (h) are g-C3N4 treated E. coli and S. pneumoniae in sunlight respectively; (d) and (i) are [email protected]3N4 treated E. coli and S. pneumoniae in dark respectively while (e) and (j) are [email protected]3N4 treated E. coli and S. pneumoniae in sunlight respectively.
Coatings 10 00950 g005
Table
Table 1. Zone of inhibition in the presence of the compound.
Table 1. Zone of inhibition in the presence of the compound.
MicroorganismsZone of Inhibition (mm)
g-C3N4[email protected]3N4Tetracycline
Escherichia coli14 ± 0.516 ± 0.520 ± 1.0
Streptococcus pneumoniae15 ± 0.518 ± 1.020 ± 1.0
Note: Zone inhibition was done at fix dose 100 µg/well on the plate in triplicate.
Table
Table 2. Minimum inhibition concentration of compound in absence and presence of sunlight.
Table 2. Minimum inhibition concentration of compound in absence and presence of sunlight.
MicroorganismsMinimum Inhibitory Concentration (MIC)
g-C3N4[email protected]3N4
DarkSunlightDarkSunlight
Escherichia coli75506030
Streptococcus pneumoniae100756025
Note: Both experiments separately done in dark and light condition.

Share and Cite

MDPI and ACS Style

Oves, M.; Ansari, M.O.; Darwesh, R.; Hussian, A.; Alajmi, M.F.; Qari, H.A. Synthesis and Antibacterial Aspects of Graphitic C3N4@Polyaniline Composites. Coatings 2020, 10, 950. https://doi.org/10.3390/coatings10100950

AMA Style

Oves M, Ansari MO, Darwesh R, Hussian A, Alajmi MF, Qari HA. Synthesis and Antibacterial Aspects of Graphitic C3N4@Polyaniline Composites. Coatings. 2020; 10(10):950. https://doi.org/10.3390/coatings10100950

Chicago/Turabian Style

Oves, Mohammad, Mohammad Omaish Ansari, Reem Darwesh, Afzal Hussian, Mohamed F. Alajmi, and Huda A. Qari. 2020. "Synthesis and Antibacterial Aspects of Graphitic C3N4@Polyaniline Composites" Coatings 10, no. 10: 950. https://doi.org/10.3390/coatings10100950

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop