BIOLOGICAL APPLICATIONS OF
PATIL AKSHAY SHASHIKANT
M PHARM Ist Yr. (PHARMACEUTICS)
DR VIJAY MISHRA (M PHARM, PHD)
1 What are C'dots ?
2 Properties of C'dots
3 Synthesis of C’dots
4 Applications of C’dots
5 Advances in bioapplications
6 New era of cancer treatment
What are C’dots ?
C’dots (or CD’s)are small carbon nanoparticle(less than
10nm in size )with same form of surface passivation .
C’dots were First discovered by XU et al., in 2004
accidently during the purification of single walled
carbon nanotubes .This Discovery triggered extensive
studies to exploit the florescence properties of C’dots.
much progress has been achieved in synthesis ,
properties and applications of C’dots.
C’dots are Biocompatible , have small size with
relatively large surface area , photostable and
having photoluminescence properties.
Fluorescent carbon dots-
carbon dots (C’dots)are currently emerging as a
class of promising fluorescent probe on account of
their low photobleaching ,versatile surfaces and
fluoroscent carbon Dots (C’dots ) have attracted
increasing attention due to their potential
application in sensing ,catalysis and biomedicine.
Excellent water solubility
Properties of carbon Dots
Natural method of manufacturing
C’dots using biomass
C’dots using plasma induced pyrolysis
C’dots from coffee grounds
C’dots using Pollen as carbon source
food wastes and harmful cyanobacteria
by carbonization of oleic acid
Synthesis of C’dots
FIG DIAGRAMS FOR THE LARGE-SCALE SYNTHESIS OF CARBON DOTS BY
(A) CHINESE INK METHOD
(B) ORANGE JUICE METHOD
(C) BEE POLLENS, AND
(D) SUCROSE AS THE CARBON SOURCE
Applications of C’Dots
C’dots were also applied in bio sensing as biosensor
carriers for their flexibility in modification, high
solubility in water, nontoxicity, good photo stability,
and excellent biocompatibility.
The biosensors based on C’dots could be used for
visual monitoring of cellular copper, glucose, pH, and
A general example is about nucleic acid lateral flow
assays. The discriminating tags on the amplicons are
recognized by their respective antibodies and
fluorescence signals provided by the attached C’dots.
C'dots possess the potential in serving as
materials for dye-sensitized solar cells,organic
solar cells, super capacitor, and light emitting
C'dots can be used as photosensitizer in dye-
sensitized solar cells and the photoelectric
conversion efficiency is significantly enhanced.
C'dots incorporated hybrid silica based sol can
be used as transparent Fluorescent paint.
The flexibility of functionalization with various groups
C’dots make them possible to absorb light of different
wavelength which offer good opportunities for applications in
C’dots modified P25TIO2 composites exhibit improved
photocatalytic H2 evaluation under irradiation with UV
The C’dots serve as Reservoir for electron to improve the
efficiency of separating of electron hole Paris of P25
C’dots have recently entered in the field of drug
delivery; moreover, it can be speculated that C’dots
can act as excellent dual functional nano-carriers
for delivering therapeutic payloads to targeted sites.
The particle size and surface properties of C’dots
can be manipulated to circumvent rapid clearance
by phagocytic cells, allowing both passive and
active drug targeting.
Drug loading capacity can be enhanced due to the
porous nature of C’dots and can be achieved without
harsh chemical reactions thus maintaining the activity of
The drug release profile can be altered and adjusted
using polymer coatings and pH responsive linkers.
Potential for administration through various routes,
including oral, pulmonary, nasal, parental, intra-ocular
C’dots with superior photo stability and low
cytotoxicity have been widely studied in optical
imaging applications as an alternative to QDs.
Both in vitro and in vivo evaluations indicated
that C’dots are excellent candidates in bio
applications due to their visible excitation and
emission wavelengths, high brightness at the
individual dot level.
Fig. Intradermal injection of CZnS-Dots: a bright field, b as-
detected fluorescence, and c color-coded images. Insets
dissected (in the circled area) axillary lymph node (LN).
The results demonstrated that C’Dots injected in various
ways into mice maintained strong fluorescence in vivo (as
shown in fig)Due to their high biocompatibility and low
cytotoxicity, C’Dots are very promising for bio imaging and
other related bio applications.
Fig. Bioimaging using fluorescent carbon dots. S. cerevisiae treated
with bare C-dots (13mg mL−1) under (a) normal light and (b)
fluorescence (𝜆 = 350 nm).
Advances in bioapplications
Absorbance and photoluminescence
C’Dots display strong optical absorption in the
UV region, with a tail extending out into the visible
range (as shown in Fig.).
Most of the one-step prepared CDs exhibit
absorbance in the range 280–360 nm . The absorption
band could be regulated via various surface
passivation or modification (as shown in Fig. )
Fig. UV–Vis absorption and normalized photoluminescence
spectra of the CDs and t-CDs. Inset: photograph of the CD
(left) and t-CD (right) aqueous solutions under visible light and
365 nm UV light, respectively. b Emission spectra of the CDs
with excitation at different wavelengths.
Quantum yield (QY)
QY is an essential parameter for luminescent
nanomaterial. The excellent photo stability was
observed in pristine C’Dots, thermally reduced C’dots.
This superior optical property attracts researchers to
concentrate on developing CDs with higher QY.
The C’dots with low toxicity and High compatibility are
applied in bioapplications as biosensors and Bioimaging
New Era Of Cancer Treatment
Cancer is considered as one of the leading cause of death
worldwide. Due to the ever changing lifestyle of the modern
society, the incidence of cancer is on the rise.
In cancer treatment,
5-FU has been proven effective against a variety of cancers
including skin, colorectal, liver, breast, pancreatic and lung
cancers with a known mechanism of action.
Now a days , New era of cancer treatment involves 5FU and
C’dots combination for cancer treatment. It was possible to
combine the merits of both CDs and 5-FU on a common platform
Fig: Multifunctional C’dots integrated hydrogels loaded with chemotherapeutic
drug, 5-Fluorouracil (5-FU@CD-HY) for simultaneous monitoring of cellular uptake
and triggering of apoptotic signaling pathway in cancer cells.
Abbreviations used: 5-Fluorouracil (5-FU), Carbon dots (CDs), Hydrogels (HY), B-
cell lymphoma 2 (bcl 2), basal cell lymphoma-extra large (bcl-xl), bcl 2 associated X
protein (bax), bcl 2 associated death promoter (bad), cytochrome c (cyt c).
 Camphor-mediated synthesis of carbon nanoparticles, graphitic shell
encapsulated carbon nanotubes and carbon dots for Bioimaging". Scientific
Reports. 6: 21286. doi:10.1038/srep21286.
 "Photoactivatable carbon nanodots for cancer therapy". Applied Physics
Letters. 103: 063701. doi:10.1063/1.4817787
 Abhay Sachdev, Ishita Matai and P.” “GopinathFluorescent carbon dots
integrated hydrogels for lung cancer therapy”research april2016
 Jia Zhang and Shu-Hong Yu* Carbon dots: large-scale synthesis, sensing
and bioimaging Materials Today _ Volume 00, Number 00 _ December 2015
. Jilong Wang1 Jingjing Qiu1 A review of carbon dots in biological
applications Received: 24 September 2015 / Accepted: 29 January 2016
Springer Science Business Media New York 2016