On–Off–On fluorescence sequential sensor for silver ions, thiamine and anti-counterfeiting application using mannitol derived carbon dots

1. M. MARUTHUPANDI
RRN: 180913701001
Ph.D. Research Scholar
Department of Chemistry
SUPERVISOR
Dr. N. VASIMALAI
ASST. PROFESSOR
Department of Chemistry

2. Tentative title
1

3. 2
Outline
Introduction
Experimental Details
& Characterizations
Application
Summary and Future
Work

4. 3
I
Introduction
Experimental Details
& Characterizations
Application
Summary and Future
Work

5.  The use of silver as an antimicrobial agent has increased of late, particularly
in wound dressings, topical agents, and medical devices
 Colloidal silver is widely purchased by people who ingest the metal in
expectation of health benefits
 Chronic exposure to silver and silver compounds leads to argyria and
argyrosis, and to other symptoms such as headaches, stomach distress,
fatigue, skin irritation, or more serious neurological, renal, or hepatic
complications
 U.S. Environmental Protection Agency (EPA) has set a maximum contaminant
level (SMCL) for silver at 0.1 mg/L 4

6.  Thiamine, also well-known as thiamin or vitamin B1
(Colorless-organosulfur)
 Vitamin B1 is an important component of balanced
healthy diets
 Thiamine deficiency has been linked to the
development of a number of diseases, including the development of autism,
Alzheimer’s disease and cancer.
 Naturally, thiamine is present in oats, rice, potatoes, eggs and grains.
 WHO recommended normal blood level amounts to above 10 Fg/100ml as
thiamine 5

7. 6
 Size: 2.5- 5 nm
 excellent optical properties,
 good biocompatibility
 aqueous solubility
 low cost
 simple synthesis, etc
CDs
Biomedical
Catalysis
Sensor
Environment
Bio-image
Drug
delivery

8. 7
E&C
Introduction
Experimental Details
& Characterizations
Application
Summary and Future
Work

9. 8

10. (a) UV-vis spectrum of
D-Mannitol-CDs,
(b) Emission spectrum
D-Mannitol-CDs,
Inset: Photographs of
MCDs (i) Day light and
(ii) UV light
9

11. 3D plot of the emission
spectra of MCDs
obtained with different
excitation wavelengths
ranging from 300 to 400
nm.
10
Emission spectra of MCDs with different excitation

12. 11

13. 12
Effect of time: Relative
emission intensity Vs Time
(min) for MCDs in the
presence of 0.07 µM Ag+
ions
Response time: 4 min

14. 13
Effect of time: Relative
emission intensity Vs Time
(min) for MCDs-AgNPs in
the presence of 0.07 µM
Thiamine ions
Response time: 4 min

15. 14
A
Introduction
Experimental Details
& Characterizations
Application
Summary and Future
Work

16. UV-vis spectra of MCDs in the presence of different concentration Ag+ ions. Linear range: 0.163 to 1.77 µM Inset:
Photographs (i) before and (ii) after the addition 1.77 µM Ag+ ion (iii) Correlation diagram.
115
LOD = 1.3 nM
UV-vis

17. 116
Emission spectra of MCDs in the presence of different concentration Ag+ ions. Linear range: 0.0817 to 0.963 µM .
Inset: UV light Photographs (i) before and (ii) after the addition 0.963 µM (iii) Correlation diagram.
LOD = 0.5 nM
PL

18. UV-vis spectra of MCDs-AgNPs in the presence of different concentration Thiamine. Linear range: 0.163 to1.77
µM. Inset: Photographs (i) before and (ii) after the addition 1.77 µM of Thiamine (iii) Correlation diagram.
117
LOD = 2.58 nM
UV-vis

19. 118
Emission spectra of MCDs-AgNPs in the presence of different concentration Thiamine. Linear range: Linear range:
0.0817 to 0.963 µM. Inset: UV light Photographs (i) before and (ii) after the addition 0.963 µM of Thiamine (iii)
Correlation diagram.
LOD = 0.577 nM
PL

20. 119
Emission spectra of
only MCDs in the
presence of different
concentration
Thiamine(a) 0, (b)
2.44, (c) 4.86, (d) 7.26,
(e) 9.63 and (f)
12.0×10-7 M. Inset:
large scle

21. 20
Ag+ 0.163 µM
Au3+ to Cr3+ 307 fold
Fe2+ to Ba2+ 613 fold

22. 21
Thiamine 0.163 µM
RF to GA 307 fold

23. Schematic representation for the possible mechanism of silver ion and thiamine sensor using 122

24. 23
S&W
Introduction
Experimental Details
& Characterizations
Application
Summary and Future
Work

25. 24
 We have successfully synthesized M-CDs at Hydrothermal
method
 The synthesized MCDs was well characterized by several
techniques
 Then, MCDs-AgNPs was used as probe for the detection of
Ag+ ions and Thiamine and LOD was found to be 0.5 and
0.577 nM by spectrofluorimetry and carried out selectivity
 Finally we have discuss possible mechanism of detection
Ag+ ions and Thiamine using MCDs

26. 25
Future characterization HR-TEM, FT-IR, Mass, XRD and
DLS spectroscopy
Then, Sensor system applying real sample analysis
Preparation of portable kit
Validation method