+ All Categories
Home > Education > Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

Date post: 29-Jun-2015
Category:
Upload: madhulika-sinha
View: 258 times
Download: 3 times
Share this document with a friend
Popular Tags:
18
Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation V 2 O 5 NW Metal Layer Bacterial Attack HOBr Production Anti-fouling Activit N o B i o f i l m f o r m a t i o n Presented By: Madhulika Sinha Green Chemistry Report Dept. Of Chemistry National Tsing Hua University
Transcript
Page 1: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart

biofilm formation

V2O5 NW

Meta

l Layer

Bacterial Attack HOBr Production Anti-fouling ActivityNo B

iofi

lm fo

rmatio

n

Presented By: Madhulika Sinha

Green Chemistry ReportDept. Of Chemistry

National Tsing Hua University

Page 2: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

OUTLINE

History Introduction Synthesis and Activities Result & Discussion Conclusion Why I chose this paper? References

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.06

Page 3: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

2013.05.06 3NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |

“And arsenic and sulphur have been well mixed with Chian oil and the mixture evenly applied to the vessel’s sides that she may speed through the blue waters freely and without impediment.”

-Translation from the Aramaic of papyrus dated 412BC

“All ships’ bottoms were covered with a mixture of tallow and pitch in the hope of discouraging barnacles and teredo and every few months a vessel had to be hove-down and graved on some convenient beach”

-Christopher Columbus

Worldwide problem in marine systems, costing US Navy alone an estimated $1 billion per annum (2002).

Fouling leads to hull roughness & hydrodynamic drag; more energy required to propel the vessel through water; increased fuel consumption & Green house gas emission4.

Tributyltin-free and Silicon elastomers A/F coatings– Not suitable results(1-4).

“fleet generates emissions equivalent to nearly 190 million cars –or all of the vehicles in the U.S”

Marine biofouling- Small marine microorganisms Colonization, adhesion of barnacles, macroalgae and microbial slimes4.

HISTORY

Page 4: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

4NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.06

INTRODUCTION −V2O5 NW

t = 0

−V2O5 NW

t = 60 days

Production of functional recombinant V-HPOs5 & isolation of naturally occurring V-HPOs6

done- withstands organic solvents, but commercial production expensive7. a)Vanadium bound to Schiff base complexes8

Functional inorg. V-HPO’s developed b) Peroxovanadium complexes9

Advantages- efficient, selective in various oxidation states8

Disadvantage- low stability and solubility, optimal working conditions (ex: organic solvents,

extremely low pH) [8-10]

Other Antibacterial NP’s like Ag, Cu, ZnO, Fe2O3 are either expensive or toxic to marine biota.

Wolfgang et al

Page 5: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.065

Vanadium Pentoxide Nano Wires(V2O5 NW) mimic naturally occurring Vanadium

Halo peroxidase (V-HPO) enzyme, prevents bio film formation. V2O5 wires in

presence of Br-, Cl- etc. and H2O2 (both present in sea water) behaves like V-HPO’s

and damage the ―quorum sensing of bacteria, without being toxic to the other

marine biota.

H2O2 + X- + H+ = HOX + H2O

H2O2 + Br- + H+ = HOBr + H2O

(oxidant) (hypobromous acid)

Singlet molecular oxygen (1O2) formed. Exerts strong antibacterial activity.

Adv. Funct. Mater. 21, 501–509 (2011)

INTRODUCTION Contd. Wolfgang et al

(hypohalous acid) (oxidant)

Page 6: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.066

Wolfgang et al

Vanadium Pentoxide Nano Wires(V2O5 NW)

50 nm

Synthesis of V2O5 NW & Bromination activity

Fig. 1 | TEM image of V2O5 nanowires

Synthesis of V2O5 NW-

VOSO4 + KBrO3 stirring for 30 min(@ RT)

180°C/24 h. Reaction cooled @ RT dark-

yellow precipitate(ppt.) dried @ 80°C overnight.

Observation: Linear dependence of the rate of 2-monochlorodimedone (MCD) bromination with V2O5 NW concentration (Fig. 2 b).

Fourfold difference in activity of the nanoscale and bulk V2O5, indicates that the higher surface area of the nanostructured material is required to achieve higher catalytic efficiency.

Chem. Rev. 104, (2004) & J. Am. Chem. Soc. 105, (1983)

Fig. 2. Concentration dependence of their bromination activity

Page 7: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.067

Wolfgang et al

V2O5 NW activity at different parameters

Fig. 3 | Steady-state kinetics of the V2O5 nanowires at pH 8.3.

3.(a) At higher concentrations of Br-, non-competitive inhibitory effect observed as in Vanadium chloroperoxidase (V-CPO) [13-15]. Such inhibition is unexpected for inorg. NP’s.

3.(b) Variation of H2O2 concentration, V2O5 nanowires, Br- and MCD Conc. constant. Michaelis– Menten behaviour observed. Steady-state kinetics determined in phosphate buffer (pH 8.0), inhibition effect did not occur, suggests that buffer plays an important role in catalysis. Values observed are similar to [ref. 16,17]

V2O5 NW tolerate higher H2O2 conc., without reduction in their catalytic activity

Page 8: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.068

Wolfgang et al

3(c) Determine pH dependence

bromination reaction rate catalyzed by

V2O5 NW using diff. buffer, constant

reactant conc.

Buffer influences the stability of Peroxo

complex formed in initial stage of

reaction.

V2O5 NW activity at different parameters

3(d), Stability of catalytic activity of

V2O5 NW over a long period.

No change in surface morphology was

observed.

Page 9: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.069

Wolfgang et al

Fig. 3(e) Proposed catalytic bromination mechanism for the V2O5 nanowires

A mechanistic proposal for the bromination activity of V2O5 in the presence of Br- and H2O2 based on the crystal structure of V2O5 and the kinetic parameters.

Figure S2 | 1O2 formation by V2O5 nanowires catalyzing the oxidation of bromide by H2O2.

The chemiluminescence derived from the singlet oxygen (1O2,1Δg) transition to stable triplet (1O2, 3Σg) was measured. A clear increase during the first 30 s is observed reaching its maximum at 75s and dropping afterwards due to H2O2 consumption.

Bromination Mechanism

Page 10: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0610

Wolfgang et al

a) Pure medium. b) Medium to which H2O2 (10 μM) and

Br- (1mM) were added. No significant color changes occur.

c) Medium to which V2O5 nanowires (0.02m/mL), H2O2 (10 μM) and Br- (1mM) were added.

Observation: A significant color change from red to purple observed due to the V2O5 mediated formation of HOBr that diffuses and reacts strongly with phenol red converting it to bromophenol. This data confirms that the V2O5 nanowires, in the presence of H2O2 and Br-, display an intrinsic brominating activity.

Figure S5 | Bromination of phenol red contained in the Mannitol Salt Phenol Red Agar (S. aureus growth medium) by V2O5 nanowires after 8h incubation at 37°C.

Bromination of the MR Agar

Page 11: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0611

Wolfgang et al

V2O5 nanowires display bromination activity in seawater

Acute toxicity (24 h LD50, dose lethal to 50% of animals tested) assessed by different

concentrations of V2O5 nanowires on a marine biota model.

In parallel, acute toxicity of different concentrations of International Maritime Organization

(IMO)- approved compounds (Zn and Cu pyrithiones—Zn/CuPT) were also determined .

Result : From dose–response curves, in terms of marine biota toxicity, V2O5 nanowires are 14

and 1,000-fold less toxic than ZnPT and CuPT, respectively.

Toxicity against Marine biota

Figure S7 | Bioassays/acute toxicity (24h LD50). The dose response curve was build for: a) CuPT, b) ZnPT and c) V2O5 nanowires.

Page 12: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0612

Wolfgang et al

Bacterial cell density/adhesion evaluated by fluorescence microscopy on the different halves of painted stainless steel plates. No significant decrease of bacterial cells adhesion is observed indicating that the V2O5 nanowires are not toxic per se and is active only the presence of the correspondent substrates (Br- and H2O2). Scale bar: 100 μm.

Fig. 5 | Potential biotechnological application of V2O5 nanowires as additive for marine paints with antibacterial/antifouling properties.

−V2O5 NW

+V2O5 NW +V2O5 NW −V2O5 NW −V2O5 NW +V2O5 NW

Pain

ted

stai

nles

s st

eel

E. coli S. aureus a b c

RESULT & DISCUSSION

Page 13: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0613

Wolfgang et al

S. aureus S. aureus+V2O5 NW +Br−+H2O2

E. coli+V2O5 NW +Br−+H2O2 E. coli

Fig. 4 | Representative digital images showing the influence of the catalytic activity of V2O5 nanowires on the growth of Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria.

a b c d

RESULT & DISCUSSION

4(b) Gram-negative: E. coli co-incubated with V2O5 nanowires, Br- and H2O2.

Decrease in bacterial population observed.

4(d) Gram-positive: S. aureus co-incubated with V2O5 nanowires, Br- and H2O2.

Color change from red to yellow indicates presence and growth of S. aureus.

Comparatively, decrease in the bacterial population (90%) observed in 4(d).

Page 14: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0614

Wolfgang et al

+V2O5 NW +V2O5 NW

t = 0 t = 60 days

Fig. 6 | Effect of nanoparticles on biofouling in situ.

6(a-b) | Immediately after fixation, both stainless-steel plates (with and without V2O5 nanowires) had clean surfaces. The boat was kept in seawater (lagoon with tidal water directly connected to the Atlantic Ocean). After 60 days, the boat was taken from the water. The painted stainless-steel plates with no V2O5 nanowires suffered from severe natural biofouling and covered with Algae. Plates with V2O5 nanowires showed a complete absence of biofouling.

Result For Real Time Experiments

Page 15: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0615

Wolfgang et al

CONCLUSION

Vanadium pentoxide nanowires have the potential to be an alternative approach to conventional anti-biofouling agents.

Page 16: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

Why I chose this Paper? Nanotechnology- One of the most explored fields of

Chemistry-Physics in the recent past (Thanks to Faraday’s

colloidal Gold suspension), must be taken into

consideration for it’s possible uses in Green chemistry

and Technology.

Many scientists and researchers are using Nanomaterials

over bulk materials for Catalysis and other metal-

catalyzed reactions.

Nanomaterials have opened a new dimension of green

chemistry by bringing down the consumption of chemicals

to nano metrics.

This paper displays one of the most important principle of

Green Chemistry “Atom Economy”.

Hence, I conclude, “SIZE DOES MATTERS”!

16NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.06

Wolfgang et al

Page 17: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0617

Wolfgang et al

[1] Appl. Environ. Microbiol. 67, 3174–3179 (2001).

[2] Environ. Sci. Technol. 25, 446–449 (1991).

[3] DOI: 10.1038/NNANO.2012.91

[4] Adv. Mater. 23, 690–718 (2011).

[5] J. Biol. Chem. 281, 9738–9744 (2006).

[6] Phytochemistry 57, 633–642 (2001).

[7] Biochemistry 34, 12689–12696 (1995).

[8] Chem. Rev. 104, 849–902 (2004).

[9] J. Am. Chem. Soc. 105, 3101–3110 (1983).

[10] J. Am. Chem. Soc. 114, 760–767 (1992).

[11] Adv. Funct. Mater. 21, 501–509 (2011).

[12] J. Biol. Chem. 263, 12326–12332 (1988).

[13] Ch. 5, 55–79 (Marcel Dekker, 1991).

[14] Proc. Natl Acad. Sci. USA 94, 2145–2149 (1997).

[15] IUBMB Life 39, 665–670 (1996).

[16] Chem. Rev. 94, 625–638 (1994).

[17] J. Am. Chem. Soc. 114, 760–761 (1992).

[18] Chem. Rev. 237, 89–101 (2003).

[19] Adv. Synth. Catal. 345, 849–858 (2003).

[20] Biochim. Biophys. Acta. 1079, 1–7 (1991).

[21] Mar. Chem. 112, 72–80 (2008).

REFERENCES

Page 18: Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

NATURE NANOTECHNOLOGY | VOL 7 | AUGUST 2012 530 |2013.05.0618

Wolfgang et al

Thank you for Listening

Any Questions?


Recommended