Free Phthalocyanine Research Articles

Solvothermal Synthesis of Rare Earth Bisphthalocyanines.

Rare earth bisphthalocyanines (MPc2) are of particular interest because of their behavior as single-molecular magnets, which makes them suitable for applications in molecular spintronics, high-density data storage and quantum computation. Nevertheless, MPc2 are not commercially available, and the synthesis routes are mainly focused on obtaining substituted phthalocyanines. Two preparation routes depend on the precursor: synthesis from phthalonitrile (PN) and the metalation of free or dilithium phthalocyanine (H2Pc and Li2Pc). In both options, byproducts such as free-base phthalocyanine and in the first route additional PN oligomers are generated, which influence the MPc2 yield. There are three preparation methods for these routes: heating, microwave radiation and reflux. In this research, solvothermal synthesis was applied as a new approach to prepare yttrium, lanthanum, gadolinium and terbium unsubstituted bisphthalocyanines using Li2Pc and the rare earth(III) acetylacetonates. Purification by sublimation gave high product yields compared to those reported, namely 68% for YPc2, 43% for LaPc2, 63% for GdPc2 and 62% for TbPc2, without any detectable presence of H2Pc. Characterization by infrared, Raman, ultraviolet-visible and X-ray photoelectron spectroscopy as well as elemental analysis revealed the main featuresof the four bisphthalocyanines, indicating the success of the synthesis of the complexes.

Investigation into electronic interaction and work function tuning of phthalocyanine molecules and graphene interfaces.

Understanding the interfacial electronic structures of organic semiconductor phthalocyanines (MePc) and graphene is essential for their practical application in various fields. In this study, we investigated the electronic structure and the tuning of the work function of free metal phthalocyanine (Pc4), cobalt phthalocyanine (CoPc), and copper phthalocyanine (CuPc) molecules deposited on a graphene monolayer using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). We found that the functionalization of MePc molecules induces p-doping to the graphene substrate due to the charge transfer mechanism with the MePc molecule. XPS analysis shows that the electronic interaction at the interface between Pc molecules and graphene substrate mainly occurs through the pyrrole species. Comparatively, it was observed that the electronic coupling between graphene and CuPc is relatively stronger than that between CoPc and graphene. The electronic interaction of the CuPc/Gr sample principally occurs through the Cu2+ 3d states of CuPc, the molecule, and the graphene 2p π states. This electronic interaction increases the work function of the graphene substrate to 5.75 eV, 6.05 eV, and 6.12 eV after depositing the Pc4, CoPc, and CuPc molecules, respectively. These results show that the MePc/Gr samples investigated in this study can be considered promising candidates for applications requiring a high work function to increase hole injection efficiency.

Calculation of the Electronic Properties Phthalocyanine (H2Pc), Silicon Phthalocyanine (Sipc), Phosphorus Phthalocyanine (PPc) and Energy Gap by the AM1 Method

Many semi-empirical methods are available in Gaussian 16. This patch enables analytical gradients and frequencies in addition to increasing efficiency by replacing the code from MOPAC open source, AM1 and PM3 technologies. In the case of a pure molecule, the values of total energy, bond energy, electronic energy, and nuclear energy (-170.893, -1496.855, -4332.708, 45) Kcal/mol have been successively added. After adding Si and P to the free Phthalocyanine molecule, the values transformed to (-133.30, -4987.486, -1294.027, 11.607) Kcal/mol. For the two resulting molecules (PcSi and PcP), the values became (-136.108, -4858.63, -9354.14, 79.930) Kcal/mol. Notably, the first number indicated an increase. Specifically, for total energy numbers, there was a decrease from -170.893 to -133.3 Kcal/mol when adding Si, and a decrease to -136.108 Kcal/mol when adding P. Overall, the energy value increased with both additions, but the bonding energy notably decreased with Si (-1496.855 to -4987.486 Kcal/mol) and P (-4858.63 Kcal/mol). Electronic energy increased from -4332.708 to -1294.027 Kcal/mol when Si was added. Nuclear energy decreased from 45.036 to 11.607 Kcal/mol when Si was added (increasing to 79.930 Kcal/mol with P). The Heat of Formation (H.o.F.) in Kcal/mol equaled 1565.04 when P was added, 1193.384 when Si was added, and 1531.528 when P was added again. The substantial impact of silicon on Phthalocyanine was evident. Furthermore, the dipole moment of the Phthalocyanine molecule, initially at D 3.687, decreased to D 2.093 and D 4.137 when Si was added first and P the second time, showcasing the significant impact of P due to its high atomic number. Determining the HOMO and LUMO and computing the values of Wavenumber, Wavelength, and Symmetry for the three molecules provided a clear illustration. The computation of electrical potential, electronic orbitals, and energy gap revealed an electronic density of 0.346 eV in the case of the free molecule H2Pc, 5.006 eV in the molecule PPc, and 5.660 eV in the case of SiPc. This offers a comprehensive understanding of the impact of adding P and Si to H2Pc.

Column chromatography separation of lanthanide(III) bisphthalocyaninate and phthalocyanine ligand

During the synthesis of double-decker f-metal phthalocyanine complexes Ln(Pc)2 free phthalocyanine ligands can be also formed, however, routine column chromatography is not effective for their separation. The preliminary reduction of the complexes with hydrazine hydrate affords the low mobile forms, which can be re-oxidized in the chromatography columns after the free ligand is eluted.

Dependence of the Color Tunability on the H2Pc Thickness in DC-Voltage-Driven Organic Light-Emitting Diodes

Dependence of the color tunability on the metal free Phthalocyanine (H2Pc) layer thickness in DC-voltage-driven organic light-emitting diodes (OLEDs) was investigated. A H2Pc layer was employed as a blue/red emission layer, which was prepared on an Alq3 green emission layer. The thickness of the H2Pc layer varied from 5 to 30 nm, with a step of 5 nm. The fabricated color-tunable OLEDs (CTOLEDs) were subjected to a thermal treatment layer for 2 min at a temperature of 120 °C to improve the interface properties, especially between H2Pc and Alq3. The current density–voltage–luminance characteristics and Commission Internationale de L’Eclairage (CIE) coordinates of the CTOLEDs with and without thermal treatment were measured, and their energy band diagrams were analyzed with respect to the H2Pc thin film thicknesses. In addition, the recombination rates at the interfaces between the hole transport layer and Alq3 and the H2Pc/electron transport layer of the CTOLEDs with and without thermal treatment were theoretically investigated using a technology–computer-aided design (TCAD) program. The experimental and theoretical results showed that the emission color temperature from cool white to warm white at a low voltage can be controlled by adjusting the thickness of the H2Pc layer in the CTOLED. It was verified that the thermally treated H2Pc thin film layer acted as a barrier that prevented electrons from being transferred to the Alq3 at low applied voltages, resulting in white color emission with temperature tunability. The CTOLED with a 20 nm of H2Pc layer demonstrated the best stable interface state and stability, resulting in the lowest driving voltage, relatively high luminance, and optimal light emission uniformity, respectively.

Electroluminescence from a phthalocyanine monolayer encapsulated in a van der Waals tunnel diode

Monolayers of free base phthalocyanine (H2Pc) are grown on monolayer and few-layer exfoliated flakes of hexagonal boron nitride (hBN) which are subsequently integrated into a van der Waals tunnel diode. This heterostructure consists of two thin hBN flakes between which the H2Pc monolayer is sandwiched and also incorporates upper and lower few-layer graphene contacts. When a voltage is applied between the contacts, a tunnel current flows and the embedded molecules can be excited resulting in the emission of photons with wavelengths which are close to the peaks observed in photoluminescence. We also observe electroluminescence at voltages where the energy gained by a tunnelling electron is lower than the energy of the emitted photon implying a multi-electron excitation pathway which we attribute to the formation of an intermediate triplet state. Our results provide insights into the differences in excitation and relaxation of molecules in supramolecular monolayers and bulk crystals and we discuss how the alignment of the energy levels of the molecules and contact layers determine the emission process.

Experimental and theoretical study of resonant core-hole spectroscopies of gas-phase free-base phthalocyanine.

We studied N 1s-1 inner-shell processes of the free base Phthalocyanine molecule, H2Pc, in the gas-phase. This complex organic molecule contains three different nitrogen sites defined by their covalent bonds. We identify the contribution of each site in ionized, core-shell excited or relaxed electronic states by the use of different theoretical methods. In particular, we present resonant Auger spectra along with a tentative new theoretical approach based on multiconfiguration self-consistent field calculations to simulate them. These calculations may pave the road towards resonant Auger spectroscopy in complex molecules.

Deformable organic semiconductor sensors based on metal free phthalocyanine for pressure and compressive displacement monitoring

Deformable organic semiconductor sensors based on metal free phthalocyanine for pressure and compressive displacement monitoring

(Digital Presentation) Monitoring and Controlling Tautomerization in Phthalocyanines, Porphyrines and Porphycenes By Optical Single-Molecule Imaging and Spectroscopy

Tautomerization is an intramolecular chemical reaction defined as structural interconversion of a molecule between two isomers separated by a low energy barrier. Tautomerization in free base phthalocyanines, porphyrins or porphycenes has fascinated and attracted chemists and physicists alike over the last decades for its fundamental importance in various chemical and biological systems and many applications in technology [1,2]. Particularly interesting is the reaction rate which can range over orders of magnitude depending on the temperature and the local environment. In solution, this reaction in porphycenes occurs usually in several picoseconds or even faster, as determined via anisotropy studies by ultrafast transient absorption spectroscopy [3] and in porphyrins at cryogenic temperatures it can last for hours or days as determined form the live time of narrow spectral holes photochemically burned in the inhomogeneously broadened absorption band with a narrow band laser [4]. However, a spectacular and unexpected observation has been made by optical single molecule imaging and spectroscopy [5]. Examining a large number of single molecules embedded at low concentration in various polymer matrices at room temperature has revealed unquestionably that the rate in these molecules can vary dramatically over time such that tautomerization can be frozen for seconds and longer under ambient conditions[6]. The interconversion of the inner protons of phthalocyanine changes the orientation of the transition dipole moment by 90o degrees with respect to the molecular structure. Hence, if these molecules are embedded with a fixed orientation in a transparent solid polymer film at high dilution and tautomerization is frozen, the orientation of their transition dipole moments can be determined by polarization spectroscopy.Here we report on our recent experimental and theoretical studies of monitoring tautomerization by fluorescence imaging of single molecules of phthalocyanines, porphyrins, or porphycenes excited in the tightly focused azimuthally and radially polarized laser beam with a sample scanning confocal optical microscope equipped with single photon counting electronics and a fluorescence spectrometer. This technique has been used to determine the transition dipole moment orientation of single molecules, the polarizability of plasmonic nanoparticles or the dimensionality of single quantum dots. Different diffraction limited fluorescence intensity patterns are observed for molecules that undergo tautomerization and for those that do not. The latter corresponds to a molecule with a fixed transition dipole moment direction, whereas the tautomerizing molecule can be treated as the superposition of two emitters with different transition dipole moment orientations.Previous studies have shown that tautomerization in porphyrins or phthalocyanines can occur via ground state tunneling and is frozen at low temperatures, particularly at cryogenic temperatures. The structural heterogeneity in a polymer matrix leads to a distribution of asymmetrically distorted ground state double well potential and hence can lead to long residence times in the deeper energy minimum. However, even at helium temperatures tautomerization can be induced by electronic excitation to the first excited state, making photochemical spectral hole-burning possible. Recently we could demonstrate in a single-molecule study that the tautomerization rate of phthalocyanine tetrasulfonate embedded in a thin PVA-film at room temperature could be controlled in a tunable λ/2 Fabry Perot resonator by weak coupling between the electronically excited state and the vacuum electromagnetic field of a resonant cavity mode.

Synthesis, characterization, electrochemical, spectroelectrochemical and dye-sensitized solar cell properties of Phthalocyanines Containing Carboxylic Acid Anchoring Groups as photosensitizer

Peripherally tetra-4-carboxyethylphenoxy substituted oxotitanium (IV), cobalt(II), zinc(II) and metal free phthalocyanines were synthesized to research the sensitizing abilities of these dye molecules in standard dye-sensitized solar cells (DSSCs). All the synthesized phthalocyanine complexes have been characterized by using elemental analyses, UV–Vis, FT-IR, 1H NMR and MALDI-TOF MS spectroscopic techniques. Electrochemistry of metallo phthalocyanines (MPcs) were studied with electrochemical and in-situ spectroelectrochemical measurements. H2Pc (7) and ZnPc (5) illustrated similar Pc based electron transfer reactions. Differently, CoPc (6) and TiOPc (4) illustrated metal based redox reactions, which enhanced the redox functionality of these complexes. Metal based reductions for CoPc (6) and TiOPc (4) were recorded in addition to the Pc based one. In-situ spectroelectrochemical measurements supported the proposed voltametric mechanism. Moreover, the color and spectra of the electrogenerated species were determined with the in-situ spectroelectrochemical analyses to predict possible optoelectrochemical application of the complexes. Pronounced optical and color changes during the electrolysis of the complexes indicated electrooptical and possible solid state electrochemical functionality of the complexes. TiO2 semiconductor on the fluoride doped indium tin oxide coated glass electrode (FTO) was decorated with H2Pc (7) and TiOPc (4) bearing four carboxyl anchoring groups and they were first of all tested as possible dye for the DSSC. H2Pc (7), TiOPc (4), CoPc (6) and ZnPc (5) dyes used in DSSCs showed 2.9%, 3.3%, 1.02% and 2.2% of power conversion efficiencies respectively.

Free base phthalocyanine coating as a superior corrosion inhibitor for copper surfaces: A combined experimental and theoretical study

In the quest of novel, eco-benign copper corrosion inhibitors, free base and a set of six metal Phthalocyanine (Pc) coatings (where metal is Zn, Cu, Fe, Co, Ni, Mn) are systematically evaluated for their corrosion inhibition efficiency. The study demonstrates that the free base Phthalocyanine coatings are superior corrosion inhibitors for Cu surface in HCl with a corrosion inhibition efficiency of 88% as compared to its metal counterparts. A detailed and indepth study involving concerted electrochemical polarisation, impedance measurements at various concentrations of HCl assert the superior corrosion inhibition efficiency of free base Pc coatings as compared to its metal counterparts. Underlying factors/interface chemistry contributing to it is brought out using first principle based studies. First principles based computational studies establish that superior corrosion inhibition ability of free base phthalocyanine molecule is attributed to its innate binding ability with copper surface and its better inter-molecular packing. Thus, the theoretical adsorption trends of various studied phthalocyanine molecules while clearly following the experimental corrosion inhibition efficiency trends undermine the importance of contribution of chelating factors for the formation of a stable and efficient corrosion inhibition coating on a surface and that the adhesion/adsorption strength of a molecule correlates directly to its corrosion inhibition efficiency. The experimental observations are further substantiated through FE-SEM, EDAX and XPS studies. The corrosion inhibition efficiency of free base phthalocyanine is followed by its zinc based counterpart at 85%.

Dual Cathepsin B and Glutathione-Activated Dimeric and Trimeric Phthalocyanine-Based Photodynamic Molecular Beacons for Targeted Photodynamic Therapy.

Two dual stimuli-activated photosensitizers were developed, in which two or three glutathione (GSH)-responsive 2,4-dinitrobenzenesulfonate (DNBS)-substituted zinc(II) phthalocyanine units were connected via one or two cathepsin B-cleavable Gly-Phe-Leu-Gly peptide linker(s). These dimeric and trimeric phthalocyanines were fully quenched in the native form due to the photoinduced electron transfer to the DNBS substituents and the self-quenching of the phthalocyanine units. In the presence of GSH and cathepsin B, or upon internalization into A549 and HepG2 cancer cells, these probes were activated through the release of free phthalocyanine units. The intracellular fluorescence intensity was increased upon post-incubation with GSH ester or reduced upon pre-treatment with a cathepsin B inhibitor. Upon light irradiation, these photosensitizers became highly cytotoxic with IC50 values of 0.21-0.39 μM. The photocytotoxicity was also dependent on the intracellular GSH and cathepsin B levels. The results showed that these conjugates could serve as smart photosensitizers for targeted photodynamic therapy.

Ultrafast charge dynamics in molecular thin films

Conjugated molecular thin films have potential for novel optoelectronic devices such as flexible solar cells and display devices. However, a detailed understanding of their excited state dynamics is crucial for their technological applications. Tetrapyrrole complexes are an important class of conjugated organic molecules for optoelectronic applications due to their high light gathering ability and thermal stability. In this review, we summarize excited state dynamics of porphyrin and phthalocyanine molecular thin films investigated by pump–probe techniques. The relaxation dynamics for metallo-phthalocyanine molecules are observed to be ultrafast in nature and are in femtosecond time scale while that for metal free phthalocyanine are moderately fast. In case of metallo-phthalocyanines exciton lifetime is much longer than for metal free phthalocyanines. The central metal atom plays an important role in the excited state dynamics of porphyrin molecular thin films thus providing additional excitation channels. Time-resolved photoemission spectroscopy reveals about the evolution of charge transfer excitons at donor–acceptor interfaces and their dissociation mechanism. In case of metallo-phthalocyanines the exciton transport is dominated by hopping mechanism rather than spatial coherent length of excitons. The pump–probe studies provide a basis for appropriate selection of molecules for technological applications.

VOCs adsorption induced surface potential changes on phthalocyanines: A combined experimental and theoretical approach towards food freshness monitoring

Many organic molecules such as porphyrins, pthalocyanines, pyrene ligands and so on are being used to detect volatile organic compounds (VOCs). The richness in π-electrons, coordination metals and their structural integrity make them as potential candidates for chemical sensing applications. In this work, metal free (H2Pc) and iron (II) phthalocyanines (FePc) are used for detecting VOCs such as 1-hexanol, nonanal, triethylamine and so on. The structural, morphological and optical properties of as deposited films of H2Pc and FePc on fluorine doped tin oxide substrates are characterized by XRD, HR-SEM, UV–Vis adsorption and Raman spectroscopy studies. Their gas adsorption properties are investigated through scanning Kelvin probe by means of change in contact potential difference in dark as well as light illumination conditions. Among both pthalocyanines, FePc shows highly selective response towards 1-hexanol under visible light exposure. Interestingly, the one to one molecular computations have revealed that FePc show higher interaction towards VOCs when compared to H2Pc. Overall, being a marker for food freshness monitoring, 1-hexanol can be detected using FePc based photo enhanced room temperature gas sensors.

Investigation of Electric and Thermoelectric Properties of Phthalocyanine monomer/dimer Molecular Junctions

In this work, we carried out a theoretical calculation to present the electrical and thermoelectrical properties of five monomers/dimers structures based on Phthalocyanine molecule sandwiched between gold electrodes. The calculation was preformed based on density functional theory (DFT) implemented by SIESTA. The results reveal that the transmission calculations T(E) of all five monomers/dimers show no spin dependent with highest value for monomer structure around Fermi energy. The phthalocyanine monomer structures show higher conductivity calculation around the Fermi energy in comparison to conductivity values of phthalocyanine dimer structures. Further, thermoelectric properties such as Seebeck coefficient (S), thermal conductance (k) and figure of merit (ZT) are also presented. It is found that the highest positive Seebeck coefficient (S) value belongs to zinc phthalocyanine monomer, while the highest negative (S) value belongs to free base phthalocyanine dimer structure over a wide range of Fermi energies. Moreover, zinc phthalocyanine monomer structure shows highest thermal conductance (k), while phthalocyanine dimer structures exhibit lowest thermal conductance (k) in the vicinity of DFT predicted Fermi energy. As a result, high room-temperature figure of merit (ZT ≈1.7) is reported for free base phthalocyanine dimer, which might be due to the low thermal conductivity and high Seebeck coefficient and electrical conductance values, which makes it a preferred candidate for potential thermoelectric applications.

Aluminum corrosion retardation properties of acetamidophenoxy phthalocyanines: Effect of central metal

Corrosion inhibition performances and adsorption behaviour at the aluminum-HCl solution interface were investigated for metal free (2), ClGa (3) and Co (4) tetrakis (4-acetamidophenoxy) phthalocyanine. Electrochemical techniques were used in the study and complemented with Fourier transform infrared, scanning electron microscopy and X-ray diffraction measurements. Potentiodynamic polarization technique gave inhibition efficiency values as 93.3% (2), 69.7% (3) and 87.7% (4) at 28°C at highest inhibitor concentration (10 µM) in the following order 2 > 4 > 3. These compounds exhibited good corrosion inhibition performance as mixed-type corrosion inhibitors. All applied techniques gave results which corroborated.

Photocytotoxicity of liposomal zinc phthalocyanine in oral squamous cell carcinoma and pharyngeal carcinoma cells.

Aim: Photodynamic therapy utilizes a light-sensitive molecule that produces reactive oxygen species following irradiation. Photodynamic activities of free Zn phthalocyanine (ZnPc) and its liposomal formulations on human oral squamous cell carcinoma and pharyngeal carcinoma cells were assessed. Materials & methods: ZnPc was incorporated in extruded and nonextruded liposomes composed of palmitoyloleoylphosphatidylglycerol (POPG):palmitoyloleoylphosphatidylcholine (POPC) or POPG:dioleoylphosphatidylethanolamine liposomes and incubated with CAL 27 or FaDu cells. Cell viability was assessed following illumination and further incubation. Results: ZnPc incorporated in extruded POPG:POPC liposomes caused extensive cytotoxicity, while ZnPc in extruded or nonextruded POPG:dioleoylphosphatidylethanolamine liposomes or in multilamellar POPG:POPC liposomes were not effective. Conclusion: Extruded POPG:POPC liposomes are a useful delivery vehicle for ZnPc in photodynamic therapy of oral and pharyngeal cancers.

Photodynamic Therapy Activity of Phthalocyanine-Silver Nanoparticles on Melanoma Cancer Cells.

The synthesis, characterization and photodynamic therapy activity of a novel metal free phthalocyanine (complex 3), with or without silver nanoparticles (AgNPs), are reported. The in vitro photodynamic activity of this complex was investigated using metastatic melanoma cancer cell line. In the presence of different concentrations of complex 3 or 3 in combination with silver nanoparticles, the viability of the cells showed a concentration dependent decrease upon irradiation with red light. The photodynamic activity of complex 3 showed an increase in the presence of the AgNPs. Although complex showed a high degree of aggregation in water, it still demonstrated reasonable potency towards the melanoma cancer cell line.

The Synthesis, Characterization, Electrochemical and Spectroelectrochemical Properties of Novel Unsymmetrical Phthalocyanines Containing Naphthoic Acid and Di-tert-butylphenoxy Groups

In this study, novel A3B-type unsymmetrically tetrasubstituted metallo and metal free phthalocyanine compounds were synthesized by a statistical condensation method using two differently substituted precursors, 4-(6-carboxy-2-naphthoxy) phthalonitrile and 4-(2,4-di-tert-butylphenoxy) phthalonitrile. The structures of the synthesized phthalocyanine compounds (ZnPc, CuPc, CoPc, NiPc and H2Pc) were characterized with spectroscopic techniques of FT-IR, UV-Vis, 1H-NMR, MALDI-TOF MS and elemental analysis. Electrochemistry of metallophthalocyanines (MPcs) was studied and electrochemical responses were compared with each other in order to understand the influence of the cations in the Pc core and substituent environment to the redox responses of them. Electrochemical characterizations indicated that one metal based reduction and one metal based oxidization processes were observed with CoPc in addition to the Pc based electron transfer reactions. Moreover ZnPc, CuPc, NiPc, and H2Pc only indicated Pc ring based redox couples. Extraordinarily, all complexes were electrodeposited on the working electrode surface during the reduction reactions which intensively altered the redox behaviors of the complexes. In situ spectroelectrochemical characterizations supported the voltammetric assignments and indicated electrocheromic functionality of the complexes. ZnPc was tested as potential dye for DSSCs and illustrated reasonable photovoltaic performance.

A phthalocyanine-based liposomal nanophotosensitizer with highly efficient tumor-targeting and photodynamic activity

Phthalocyanines are promising photosensitizers for photodynamic therapy (PDT), but the inherent tendency of aggregation generally leads to the decrease or even quenching of photoactivities. To address this issue and realize the desirable photodynamic therapeutic effect of phthalocyanines, herein, we report a folate-modified phthalocyanine-based liposomal nanophotosensitizer (PcN@Lip-FA), which can be prepared through a facile “one-pot” method. An analogue (PcN@Lip) without folate was also prepared as a negative control. The liposomal nanophotosnesitizers greatly prevented the aggregation of the zinc(II) phthalocyanine (PcN) and showed highly efficient photoactivities (fluorescence and singlet oxygen generation) in aqueous solutions, although the free PcN is severely aggregated and its photoactivities are nearly quenched. The in vitro results demonstrate that PcN@Lip-FA can be taken in by folate receptor (FR)-positive HeLa cells through FR-mediated process, and exhibits significantly higher cellular uptake and photocytotoxicity against HeLa cells than both PcN@Lip and PcN, but for FR-negative MCF-7 cells, PcN@Lip-FA and PcN@Lip show comparable photocytotoxicity. In addition, with the folate vector, PcN@Lip-FA has highly efficient tumor targeting and PDT effect on the S180 rat ascitic tumor-bearing mice with a tumor inhibition rate up to 98.0%. Therefore, the liposomal nanophotosensitizer PcN@Lip-FA can serve as a promising nanoplatform for cancer diagnosis and targeted PDT.