Poly (ethylene oxide) tethered trans-porphyrin: Synthesis, self-assembly with fullerene (C60) and DNA binding studies

Article abstract of DOI:10.1016/j.molliq.2016.11.059

trans-Porphyrin containing phenyl group at both ends was synthesized via corresponding dipyrromethanes (DPM) in the presence of TFA and DDQ. The polyethyleneglycole (PEG) chains were attached at the trans positions of ABA type porphyrinic moiety. The prep

Full text of DOI:10.1016/j.molliq.2016.11.059

Poly (ethylene oxide) tethered trans-porphyrin: Synthesis, self-assembly with
fullerene (C60) and DNA binding studies
Muhammad Asim Akhtar, Sara Riaz, Akhtar Hayat, Muhammad Nasir,
Nawshad Muhammad, Abdur Rahim, Mian Hasnain Nawaz
PII:
DOI:
Reference:
S0167-7322(16)33149-X
doi:10.1016/j.molliq.2016.11.059
MOLLIQ 6606
To appear in:
Journal of Molecular Liquids
Received date:
Revised date:
Accepted date:
13 October 2016
14 November 2016
17 November 2016
Please cite this article as: Muhammad Asim Akhtar, Sara Riaz, Akhtar Hayat, Muham-
mad Nasir, Nawshad Muhammad, Abdur Rahim, Mian Hasnain Nawaz, Poly (ethylene
oxide) tethered trans-porphyrin: Synthesis, self-assembly with fullerene (C60) and DNA
binding studies, Journal of Molecular Liquids (2016), doi:10.1016/j.molliq.2016.11.059
This is a PDF file of an unedited manuscript that has been accepted for publication.
As a service to our customers we are providing this early version of the manuscript.
The manuscript will undergo copyediting, typesetting, and review of the resulting proof
before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that
apply to the journal pertain.

ACCEPTED MANUSCRIPT
Poly (ethylene oxide) Tethered trans-Porphyrin: Synthesis, Self-assembly with
Fullerene (C60) and DNA Binding Studies
Muhammad Asim Akhtar,a Sara Riaz,b Akhtar Hayat,a Muhammad Nasir,a Nawshad
Muhammad,a Abdur Rahim,a Mian Hasnain Nawaz *a
a Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute
of Information Technology, Lahore
b Department of Chemical Engineering, COMSATS Institute of Information
Technology, Lahore
Graphical Abstract
We report here, the synthesis and morphological investigation of ABA type PEGylated trans-
porphyrin, P-(PEO)2. These porphyrinic moieties self-assembled into spheres of uniform
diameter when their DMF solution was dialyzed into water. Furthermore, the addition of C60 to
P-(PEO)2 caused morphological change of worm like lateral aggregates. The aggregates were
further studied for DNA attachment using change in their electrochemical properties.

ACCEPTED MANUSCRIPT
Abstract
Trans-porphyrin containing phenyl group at both ends was synthesized via
corresponding dipyrromethanes (DPM) in the presence of TFA and DDQ. The
polyethyleneglycole (PEG) chains were attached at the trans positions of ABA type
porphyrinic moiety. The prepared PEGylated porphyrin (with PEG arms at the
periphery) P-(PEO)2 was self-assembled into spheres of uniform diameter while
their DMF solution was dialyzed into water. Furthermore, the addition of fullerene
(C60) to P-(PEO)2 caused complexation between porphyrin and fullerene which
lead to interesting and trenchant morphology having worm like lateral aggregates.
The assembly process and the as-prepared edifices were characterized using
UV−vis absorption spectroscopy and the morphology of these assemblies was
investigated using transmission electron microscope (TEM). Furthermore, the
DNA binding with porphyrin aggregates has been demonstrated via
electrochemical (cyclic voltammetric) response of screen printed electrodes
modified. The obvious increase in redox current disclosed the intermolecular
interactions of the adducts with the DNA. These studies of unprecedented adducts
can further be explored for potential applications in biosensors.
Keywords: Porphyrins Aggregates; Fullerenes; Polymeric Composites; Self-
assembly; DNA attachment

ACCEPTED MANUSCRIPT
1. Introduction
In last few decades, inspired by the nature a great variety of porphyrin derivatives
have been synthesized and is still the impetus for the current fabrication of smart
materials e.g. sensors, biosensors, drug carriers and solar cells.[1, 2] Primarily
these derivatives have been used as sensitizers in both natural and artificial systems
for their ultrafast electron injection,[3] small splitting and prolonged excited state
life time,[4] higher absorption coefficients and stability[5] along with the other
uses of photochemistry and construction of hybrid materials.[6] Similarly, much
attention has been made to explore molecular assemblies and their organization
which is governed by the cooperative interactions of various noncovalent bonds,
such as hydrophobic interaction, π−π stacking, and electrostatic interaction, where
the hydrogen bonding gives additional driving as well as regulating forces.
Porphyrin has also attracted the researchers to the distinct dependence of its mode
of self-assembly on the peripheral substituent,[7] additionally; the axial ligand and
protonation at the core could also affect the aggregation behavior of porphyrin
substantially.[8] Similarly, porphyrins can be incorporated into the micelles
resulting in the alteration of their mode of aggregation and location.[9]
On the other side, in nature, photo induced electron transfer is the core of natural
photosynthesis process, which is a multistep and unidirectional in nature, where the
spatial arrangement of donor-acceptor (D-A) chromophores of transmembrane
protein is very important. Hence the construction of D-A conjugated systems with
restricted spatial arrangement is very attractive field of research in mimicking of
natural photosynthesis process.[10] In this avenue, porphyrin-fullerene conjugates
act as excellent electron donor-acceptor building blocks and have been widely used
to optimize the light harvesting and electron transfer efficiency by adjusting the
distance and orientation of individual units by face-to-face and edge-to-edge

ACCEPTED MANUSCRIPT
alignment.[11, 12] Trans-porphyrin could help better to construct porphyrin based
well defined architectures by linear substitution patterns, and are the key
components of model systems including mimicking of enzyme models,
photosynthesis, optical properties, catalysts, sensors, small molecule receptors and
so on.[13] To be specific trans-substituted porphyrins, decorated with functional
groups at the periphery of 18π- electron system, have been synthesized by
MacDonald type synthesis to give wide range of substituents at the periphery
positions.[14] For the possible utility of trans-porphyrin in well-defined
architectures, and their structural specificity compared to general meso-A4
porphyrins, they have great importance in bio-mimicry which further depends on
the functionalities attached as meso-substituents, because the terminal functional
groups have vital role in self-assembly and surface attachment.[15, 16]
Furthermore, the porphyrin with its nature of unique aromatic scaffolds endowed
quite important DNA binding potency, especially the noncovalent interactions of
DNA (both double stranded and single stranded) with porphyrin, which have been
studied using NMR, spectroscopy, biophysical studies and molecular
modeling.[17, 18] For the stronger interactions, the smart engineering of particular
porphyrin molecules is the most influential factor of porphyrin ligands in hosting
the DNA[19] that have potential applications in anti-cancer drugs.
To improve the solubility and functionality, this study aims to explore the synthesis
and characterization of double PEGylated porphyrins and further to study their
morphological changes during complexation with fullerene. The morphology of
the self-assembled architectures was investigated using transmission electron
microscope (TEM) and the molecular attachments were characterized using
UV−vis absorption spectra. Moreover, we studied the DNA binding to these self-
assembled architectures via electrochemical (cyclic voltammetric) responses of

ACCEPTED MANUSCRIPT
screen printed electrodes modified with these adducts. To the best of our
knowledge, it is the first time to study the DNA attachment with
porphyrin/fullerene assembled architectures.
2. Experimental
2.1.Materials
Pyrrole (C4H5N, 98%), benzaldehyde (C6H5CHO, 99%), 4-hydroxybenzaldehyde
(HOC6H4CHO, 97%), poly(ethylene oxide) (1000 g.mol-1), N, Nʹ-
dicyclohexylcarbodiimide
(DCC),
4-dimethylaminopyridine
(DMAP),
Trifluoroacetic acid (TFA), 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ),
and triethylamine were purchased from Sigma-Aldrich and Aladdin. Fullerene
(C60, 99.5%) was purchased from Bucky, USA and used as received. All the
solvents and other chemicals were purchased from Sinopharm Chemical Reagent
Co., Ltd or Shanghai Lingfeng Chemical Reagent Company and were used as
received.
2.2.Characterization
1H NMR spectra were recorded at 400 MHZ, using BRUKER AV400
Spectrophotometer. The samples were dissolved in CDCl3, and measured using
tetramethylsilane (TMS) as an internal reference. Gel permeation chromatography
(GPC) measurements were performed with Styragel HR3-HR4 (7.8×300 mm)
columns equipped with Waters 1515 isocratic HPLC pump and Waters 2414
Refractive Index Detector with flow rate of 1 ml/min, and the instrument was
calibrated using polystyrene standards. UV-vis. spectroscopy traces were recorded
at SHIMADZU UV-2550 UV spectrophotometer using 2.5 mL sample in quartz
Cuvettes with 1 cm beam path length, at room temperature. Fluorescence
measurements were performed at Varian’s Cary Eclipse fluorescence

ACCEPTED MANUSCRIPT
spectrophotometer at room temperature with and the excitation wavelength is 420
nm. In order to avoid spectral distortions very dilute solutions were used for both
UV and fluorescence measurements. Transmission electron microscopy (TEM)
images were taken on a JEOL JEM1400 electron microscope operated at 100 kV.
A 5 μL droplet of self-assembly aggregate solution (0.5 mg/mL) was directly
dropped onto a copper grid (300 mesh) coated with a carbon film, followed by
drying at room temperature. Surface morphologies of modified electrodes was
investigated with scanning electron microscopy (SEM) by using TESCAN VEGA
3 and dynamic light scattering measurements for particle size determination were
performed at NICOMP TM 380ZLS of PSS-NICOMP particle size systems, USA.
2.3.Synthesis of 2, 2ʹ-(phenyl methyl)bis(1H-pyrrole) / (phenyl-
dipyromethane), DPM
Phenyl-dipyrromethane was synthesized by the reported method,[20] where
distilled pyrrole (17 mL, 245 mmol) was placed in a round bottom flask followed
by the addition of benzaldehyde (1 mL, 9 mmol, 1.0 equiv) under Ar, at room
temperature. After stirring the mixture for 5 min, trifluoroacetic acid (TFA) (0.225
mL, 0.9 mmol, and 0.10 equiv.) was added drop wise and stirring was continued
for another 5 min under Ar atmosphere followed by quenching of the reaction with
0.1 M NaOH. In the vigorously stirring mixture ethyl acetate was added and then
washed with H2O and dried over Na2SO4. Orange oil was obtained after removal of
the solvent in reduced pressure while the crude product was collected from
ethanol/water as yellowish crystals, (1.0 g, and yield 46%). 1H NMR (400 MHz,
CDCl3, figure 5.2), δ ppm: 7.92 (bs, 2H, NH-pyrrole), 7.22-7.35 (m, 3H, phenyl),
6.7 (d, 2H, α-pyrrole), 6.2 (t, 2H, β-pyrrole), 5.85 (d, 2H, β-pyrrole), 5.50 (s, 1H,
C-CH-C), the spectrum is provided as supplementary figure S1.

ACCEPTED MANUSCRIPT
Figure.1 Schematic representation of synthesis route for P-(PEO)2 starting from
pyrrole and benzaldehyde.
2.4.5,15-Bis(4-hydroxyphenyl)-10,20-diphenyl porphyrin, (P-(OH)2
Trans-porphyrin was synthesized according to the following procedure,[21, 22]
where 2, 2'-(phenyl methyl)bis(1H-pyrrole), DPM (0.225 g, 1mmol), and 4-
hydroxybenzaldehyde (0.123 g, 1 mmol) were added in
800 mL of
dichloromethane and stirred under Ar bubbling for 20 min. Then 10 mL DCM
solution of TFA (0.131 mL, 1.7 mmol) was added with dropper in Ar atmosphere
and stirred for 3 h followed by the addition of DDQ (0.23 g, 1.5 mmol) with
vigorous stirring for 1 h and the reaction was quenched with triethylamine (3-5
mL). At the end the resultant solution mixture was passed through a pad of silica
gel to collect the first band, which was concentrated under vacuum and the product
was precipitated by DCM/ methanol, (0.04 g, yield 18 %). The product was
characterized by 1H NMR as shown in figure 5.4 (400 MHz, CDCl3), δ ppm: 8.8

ACCEPTED MANUSCRIPT
(d, 8H, β-pyrrole), 8.25 (d, 4H, meta-phenyl), 8.15 (d, 4H, ortho-phenyl), 7.75 (m,
10H, ortho/meta/pera-phnyl), -2.77 (s, 2H, NH-pyrrole), the spectrum is given as
figure S2.
2.5.Synthesis of PEGylated trans-Porphyrin, P-(PEO)2
The doubly PEGylated trans-porphyrin was obtained by DMAP and DCC assisted
esterification of hydroxyl functionalized porphyrin (P-OH2) and PEO-COOH
(1000 Da) according to the reported method[15] which gave the target molecule of
P-PEO2. Typically, P-OH2 (0.025 g, 0.04 mmol), PEO-COOH (0.085 g, 0.15
mmol) and DMAP (0.004 g, 0.04 mmol) were dissolved in dry DCM at 10 ˚C
under N2, and after 20 min stirring, 10 mL DCM solution of DCC (0.032 g, 0.15
mmol) was drop wise added to the mixture. The reaction mixture was stirred for 48
h at room temperature, and then solvent was evaporated under reduced pressure
and the product was precipitated in cold ether. The product was characterized by
1
gel permeation chromatography and H-NMR, 1H NMR (CDCl3, 400 MHz): 8.85
(d, 8H, β-pyrrole), 8.23 (d, 8H, ortho-phenyl), 7.8 (m, 9H, meta/para-phenyl), 7.56
(d, 2H, meta-phenyl), 4.25 (t, COOCH2), 3.65 (m, OCH2CH2O), 3.4 (s, CH3O),
2.63 (m, OCOCH2CH2OCO), −2.73 (s, 2H, NH-pyrrole), the 1H-NMR spectrum is
provided as figure 2.

ACCEPTED MANUSCRIPT
1
Figure.2 H NMR spectra of P-(PEO)2, showing typical porphyrinic protons along
with the ethylene oxide protons at 3.6 ppm.
2.6.Morphology investigation of P-(PEO)2 and its complexation with C60
Due to their homophilic nature, these ABA type trans porphyrins might have
variety of solvent options for their self-assembly studies. Different solubility
profiles of various segments of this poly (ethylene oxide)-porphyrin-poly (ethylene
oxide) (PEO-P-PEO) tri-block molecule could expectedly give interesting
morphology. Here the self-assembly of P-(PEO)2 and P-(PEO)2-C60 were studied in
DMF via dialysis in the selective solvent (H2O) that assembled these adducts
concordant by their natural affinities. Initially, P-(PEO)2 was dissolved in DMF as
stock solution. Aliquot of stock solution was added into 3 mL of DMF to make the
total solution concentration at 1×10-4 M which is above the critical micelles
concentration (the critical micelles concentration was estimated by UV-vis spectra,
as discussed below), then the solution was subjected to dialysis into water by
placing it in dialysis membrane (MWCO = 3500 Da). The changes in color after
dialysis was observed.

ACCEPTED MANUSCRIPT
2.7.DNA attachment studies of P-(PEO)2
The water soluble trans porphyrins were expected to give better DNA attachment
with central part of the PEGylated moiety which will further broaden the
knowledge of DNA attachment with porphyrins. DNA of the sequence 5′-
GCAGTTGATCCTTTGGATACCCTGG-3 was used in this study, prior to the
experimentation, initial heat treatment was performed to obtain the single strands
of DNA. In 2 mL of porphyrinic solution (1×10-5 M) equimolar concentration of
DNA (40 µL of DNA stock solution) was added and the resulting solution was
incubated for 10 min before the analysis. The changes in the voltamograms of
different porphyrinic assemblies indicated the complexation with DNA.
3. Results and Discussion
As the spectral properties are the finger prints for aggregation, initially the UV-vis
spectra were analyzed for the aggregation of adduct in aqueous solvent. Poly
(ethylene oxide) arms associated with the porphyrin, made the molecule soluble in
water, which showed typical absorption bands due to in-plan π-π* transition,[23]
named as soret band. In absorption spectra one intense soret band appeared at 417
nm and four (relatively week) Q bands at 516, 551, 592, and 647 nm. Moreover, at
very low concentration, porphyrin was found in monomeric form in water, as can
be evidenced from the UV-vis spectra of P-(PEO)2 in water at 2.5 ×10-6 to 2×10-5
M, (Figure S6). The critical micelle concentration (CMC) can also be deduced
from the UV-vis titration of the aqueous solution, as shown in figure S6, the
gradually increasing concentration of porphyrin in the water solution showed
increasing soret band intensity, while the splitting of soret band into two
aggregation bands at 407, 420 nm, was occurred between 5×10-5 and 1.0×10-4 M,
that gives an idea of the presence of CMC between these two values.[24] Hence,

ACCEPTED MANUSCRIPT
the morphological investigations of P-(PEO)2 were conducted above the CMC at
1.0×10-4 M.
Figure.3 (A) UV-vis absorption spectra of P-(PEO)2 nanospheres (a) and P-(PEO)2-
C60 aggregates (b), the inset showing visual appearance of the solutions and
(B) fluorescence emission spectral changes on complexation of P-(PEO)2
with fullerene after dialysis in H2O (inset showing the fluorescent images of
the solutions).
Furthermore, the soret band of P-(PEO)2-C60 aggregates shows red shift, indicating
the presence of slipped face-to-face J aggregates [25] of porphyrin-fullerene that
could further be correlated with the morphology observed by transmission electron
microscopic studies. On the other side, on complexation of these amphiphilic
porphyrins with pristine C60 there was a clear red shift of about 13 nm, from 415
nm to 428 nm, in the soret band of porphyrin and visible color change of the
solution which was a characteristic of these molecular level interactions of donor-
acceptor (porphyrin-fullerene) moieties,[26] as shown in figure 3A, The color of
the solution was light pink which was faded away after dialysis, as can be seen

ACCEPTED MANUSCRIPT
from figure 3A. This porphyrin-fullerene complexation was also corroborated by
fluorescence quenching of porphyrin as shown in figure 3B. The fluorescent
images also elaborated the quenching hypothesis,[27] as the porphyrin-fullerene
complex showed less fluorescent image in dark background as compared to the
porphyrin solution. One more possible change in the original spectra of porphyrin
is the decrease in absorption intensity of the soret band, but here during the dialysis
turgidity of dialysis membrane caused dilution of the solution approximately up to
two times, which also caused a significant decrease in the intensity of the soret
band, therefore the decrease in the soret intensity due to porphyrin-fullerene
complexation could not be quantified in the present case.
Transmission electron microscopy of aqueous solutions of P-(PEO)2 shows
spherical aggregates of highly monodispersed nature, as shown in figure 4a. The
sample was prepared by first dissolving P-(PEO)2 in DMF, a good solvent for all
the segments, then gradual dialysis of DMF solution into water, in which central
porphyrinic part of P-(PEO)2 is insoluble. The porphyrin in DMF could arrange
itself freely, while the slow dialysis in water permits the gradual removal of DMF
and addition of water to the micelles solution. It is noteworthy, that the annealing
time (rate of solvent interchange during the dialysis) which apparently seizes
morphology at the core, is an important factor for the morphology of such
aggregates.

ACCEPTED MANUSCRIPT
Figure.4 TEM micrographs of self-assembled (a) P-(PEO)2 (Mw=2700 Da), and (b)
the complex of P-(PEO)2 and C60 showing highly monodispersed spherical
aggregates of the average size ca. 80 nm and lateral aggregates with varying
length, (c) SEM lateral assemblies of P-(PEO)2 and C60 complex. The inset
of (a) showing the hydrodynamic diameter (Rh = 170 nm) of spherical
aggregates of P-(PEO)2
In these aggregates porphyrin moieties were encapsulated with in polymeric matrix
of PEO. The average size of the spherical aggregates was found to be about 80 nm
as depicted in the following TEM micrographs, however the hydrodynamic
diameter was found to be 170 nm which is in good agreement with dry and wet
calculations of the diameter.[28] Interestingly, the lateral aggregates of 100 nm
width and varied length were observed, when these PEGylated porphyrins were
complexed with C60 in DMF followed by the dialysis into water, as shown in figure
4b. Deducing from the spectral (red shift of soret band) and microscopic
observations, these lateral aggregates could be considered as face-to-face
aggregates of alternating porphyrin-fullerene molecules.

ACCEPTED MANUSCRIPT
Figure.5 Cyclic voltammograms of bare screen printed electrode (a), P-(PEO)2
nanospheres modified electrode (b) and P-(PEO)2-C60 aggregates modified
electrodes (c) against DNA at a scan rate of 50 mVs-1 in the potential range of
-0.6 V to 0.8 V.
Cyclic voltammetery was performed to evaluate the electrochemical behavior of
self-assembled aggregates of P-(PEO)2 and its C60 complexes by modifying carbon
based screen printed electrodes. Figure5 represents cyclic voltammetery curves of
bare electrode, P-(PEO)2 nanospheres modified electrode and P-(PEO)2-C60
aggregates modified electrodes against DNA. It was observed that although the
characteristic oxidation reduction peaks of porphyrin and fullerene were absent in
either case however with the modification of electrode the current was significantly
increased which shows the enhanced conductivity of the electrodes, modified with
self-assembled nanoparticles.[29] Additionally, on complexation of P-(PEO)2 with
C60, being the donor-accepter pair, current should be increased, but it was
decreased as compared to P-(PEO)2 spheres. This unexpected change could be

ACCEPTED MANUSCRIPT
attributed to the uniformity and specific orientation of the porphyrin molecules
with respect to the fullerene. Apparently the more number of active sites and larger
surface of the nanospheres resulted in increased current as compared to lateral
aggregates of P-(PEO)2-C60 complexes.
4. Conclusion
The doubly PEGylated trans-porphyrin was successfully synthesized and
characterized with NMR and SEM analysis. The enhanced solubility profile of the
P-(PEO)2 made it susceptible to form various self-assemblies including highly
monodispersed nanospheres of 80 nm diameter and trenchant lateral aggregates
with and without C60 complexation, respectively. The aggregates were
characterized both in wet and dry states by optical and spectroscopic studies. The
practical perspectives of these adducts for DNA attachment were also
demonstrated with the help of electrochemical characterization in aqueous
solutions. These findings will help to further explore the applications of these types
of porphyrin derivatives and their self-assembled aggregates in both energy and the
biomedical fields.
Acknowledgment
The financial support (21-329/SRGP/R&D/HEC/2014 and 20-4993/R&D/HEC/14)
from higher education commission Pakistan is acknowledged.

ACCEPTED MANUSCRIPT
References
[1] Y. Xu, Z. Liu, X. Zhang, Y. Wang, J. Tian, Y. Huang, Y. Ma, X. Zhang, Y.
Chen, A Graphene Hybrid Material Covalently Functionalized with Porphyrin:
Synthesis and Optical Limiting Property, Advanced Materials, 21 (2009) 1275-
1279.
[2] C.M. Drain, A. Varotto, I. Radivojevic, Self-organized porphyrinic materials,
Chem Rev, 109 (2009) 1630-1658.
[3] M.J. Griffith, K. Sunahara, P. Wagner, K. Wagner, G.G. Wallace, D.L. Officer,
A. Furube, R. Katoh, S. Mori, A.J. Mozer, Porphyrins for dye-sensitised solar
cells: new insights into efficiency-determining electron transfer steps, Chem
Commun (Camb), 48 (2012) 4145-4162.
[4] J. Yu, X. Wang, B. Zhang, Y. Weng, L. Zhang, Prolonged Excited-State
Lifetime of Porphyrin Due to the Addition of Colloidal SiO2to Triton X-100
Micelles, Langmuir, 20 (2004) 1582-1586.
[5] C.P. Tidwell, P. Bharara, G. Rudeseal, T. Rudeseal, F.H. Rudeseal, Jr., C.A.
Simmer, D. McMillan, K. Lanier, L.D. Fondren, L.L. Folmar, K. Belmore,
Synthesis and characterization of 5,10,15,20-tetra[3-(3-trifluoromethyl)phenoxy]
porphyrin, Molecules, 12 (2007) 1389-1398.
[6] X.B. Ren, M. Chen, D.J. Qian, Pd(II)-mediated triad multilayers with zinc
tetrapyridylporphyrin and pyridine-functionalized nano-TiO2 as linkers: assembly,
characterization, and photocatalytic properties, Langmuir, 28 (2012) 7711-7719.
[7] Y. Rong, P. Chen, D. Wang, M. Liu, Porphyrin assemblies through the
air/water interface: effect of hydrogen bond, thermal annealing, and amplification
of supramolecular chirality, Langmuir, 28 (2012) 6356-6363.
[8] Y. Qiu, P. Chen, M. Liu, Interfacial assemblies of atypical amphiphilic
porphyrins: hydrophobicity/hydrophilicity of substituents, annealing effects, and
supramolecular chirality, Langmuir, 26 (2010) 15272-15277.
[9] L. Guo, Y.-q. Liang, pH-controlled location and metalation of an amphiphilic
porphyrin in sodium dodecyl sulfate micelle, Canadian Journal of Chemistry, 80
(2002) 1655-1661.
[10] H. Xu, J. Zheng, Face-to-Face Alignment of Porphyrin/Fullerene Nanowires
Linked by Axial Metal Coordination, Macromolecular Chemistry and Physics, 211
(2010) 2125-2131.
[11] D.M. Guldi, C. Luo, M. Prato, A. Troisi, F. Zerbetto, M. Scheloske, E. Dietel,
W. Bauer, A. Hirsch, Parallel (Face-to-Face) Versus Perpendicular (Edge-to-Face)
Alignment of Electron Donors and Acceptors in Fullerene Porphyrin Dyads: The
Importance of Orientation in Electron Transfer, Journal of the American Chemical
Society, 123 (2001) 9166-9167.

ACCEPTED MANUSCRIPT
[12] T. Hasobe, S. Hattori, P.V. Kamat, Y. Urano, N. Umezawa, T. Nagano, S.
Fukuzumi, Organization of supramolecular assemblies of fullerene, porphyrin and
fluorescein dye derivatives on TiO2 nanoparticles for light energy conversion,
Chemical Physics, 319 (2005) 243-252.
[13] B.J. Littler, Y. Ciringh, J.S. Lindsey, Investigation of Conditions Giving
Minimal Scrambling in the Synthesis of trans-Porphyrins from Dipyrromethanes
and Aldehydes, J Org Chem, 64 (1999) 2864-2872.
[14] D. Daphnomili, M. Grammatikopoulou, C. Raptopoulou, G. Charalambidis, T.
Lazarides, A.G. Coutsolelos, A synthetic approach of new trans-substituted
hydroxylporphyrins, Bioinorg Chem Appl, 2010 (2010) 307696.
[15] J. Lee, Y. Kim, S.K. Kang, I. Choi, J. Yi, Synthesis oftrans-substituted
porphyrin building blocks containing two S-trityl or thiol groups, Korean J. Chem.
Eng., 23 (2006) 512-515.
[16] V. Villari, P. Mineo, E. Scamporrino, N. Micali, Spontaneous self-assembly
of water-soluble porphyrins having poly(ethylene glycol) as branches: Dependence
of aggregate properties from the building block architecture, Chemical Physics,
409 (2012) 23-31.
[17] L.G. Marzilli, D.L. Banville, G. Zon, Pronounced proton and phosphorus-31
NMR spectral changes on meso-tetrakis(N-methylpyridinium-4-yl)porphyrin
binding
to
poly[d(G-C)].cntdot.poly[d(G-C)]
and
to
three
tetradecaoligodeoxyribonucleotides: evidence for symmetric, selective binding to
5'CG3' sequences, Journal of the American Chemical Society, 108 (1986) 4188-
4192.
[18] A.B. Guliaev, N.B. Leontis, Cationic 5,10,15,20-Tetrakis(N-
methylpyridinium-4-yl)porphyrin Fully Intercalates at 5‘-CG-3‘ Steps of Duplex
DNA in Solution, Biochemistry, 38 (1999) 15425-15437.
[19] G. Pratviel, Porphyrins in complex with DNA: Modes of interaction and
oxidation
reactions,
Coordination
Chemistry
Reviews,
DOI
10.1016/j.ccr.2015.07.003(2015).
[20] B.J. Littler, M.A. Miller, C.-H. Hung, R.W. Wagner, D.F. O'Shea, P.D. Boyle,
J.S. Lindsey, Refined Synthesis of 5-Substituted Dipyrromethanes, The Journal of
Organic Chemistry, 64 (1999) 1391-1396.
[21] R. Acharya, L. Paudel, J. Joseph, C.E. McCarthy, V.R. Dudipala, J.M.
Modarelli, D.A. Modarelli, Synthesis of Three Asymmetric N-Confused
Tetraarylporphyrins, The Journal of Organic Chemistry, 77 (2012) 6043-6050.
[22] B.J. Littler, Y. Ciringh, J.S. Lindsey, Investigation of Conditions Giving
Minimal Scrambling in the Synthesis of trans-Porphyrins from Dipyrromethanes
and Aldehydes, The Journal of Organic Chemistry, 64 (1999) 2864-2872.

ACCEPTED MANUSCRIPT
[23] S. Banik, J. Bhattacharjee, S.A. Hussain, D. Bhattacharjee, Clay induced
aggregation of a tetra-cationic metalloporphyrin in Layer by Layer self assembled
film, Journal of Physics and Chemistry of Solids, 87 (2015) 128-135.
[24] A. Dominguez, A. Fernandez, N. Gonzalez, E. Iglesias, L. Montenegro,
Determination of Critical Micelle Concentration of Some Surfactants by Three
Techniques, Journal of Chemical Education, 74 (1997) 1227.
[25] Q. Zou, L. Zhang, X. Yan, A. Wang, G. Ma, J. Li, H. Mohwald, S. Mann,
Multifunctional porous microspheres based on peptide-porphyrin hierarchical co-
assembly, Angewandte Chemie, 53 (2014) 2366-2370.
[26] M.H. Nawaz, J. Liu, F. Liu, X. Wang, W. Zhang, Synthesis of porphyrinic
polystyrenes and their self-assembly with pristine fullerene (C60), Materials
Letters, 91 (2013) 71-74.
[27] S.A. Vail, J.P.C. Tomé, P.J. Krawczuk, A. Dourandin, V. Shafirovich, J.A.S.
Cavaleiro, D.I. Schuster, Synthesis and fluorescence properties of a porphyrin–
fullerene molecular wire, Journal of Physical Organic Chemistry, 17 (2004) 814-
818.
[28] H. Fissan, S. Ristig, H. Kaminski, C. Asbach, M. Epple, Comparison of
different characterization methods for nanoparticle dispersions before and after
aerosolization, Analytical Methods, 6 (2014) 7324-7334.
[29] L.J. Santos, D. CarvalhoDa-Silva, J.S. Rebouças, M.R.A. Alves, Y.M.
Idemori, T. Matencio, R.P. Freitas, R.B. Alves, Synthesis of new
porphyrin/fullerene supramolecular assemblies:
a
spectroscopic and
electrochemical investigation of their coordination equilibrium in solution,
Tetrahedron, 67 (2011) 228-235.

ACCEPTED MANUSCRIPT
Poly (ethylene oxide) Tethered trans-Porphyrin: Synthesis, Self-assembly with
Fullerene (C60) and DNA Binding Studies
Highlights
 We synthesized trans-functionalized porphyrin and study their self-assembly
behaviors.
 Monodispersed nanoshperes and lateral aggregates of porphyrin-fullerene
complexes were obtained as studied by using TEM.
 Effects of different parameters on morphology were studied.
 Screen printed electrodes were modified with these aggregates via drop
costing method for electrochemical studies.
 Aggregates were used to study the DNA attachment for biosensing
applications.