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While hole extraction is crucial for the external quantum efficiency of conventional n-i-p colloidal quantum dot (CQD) solar cells (CQDSCs), sulfur-passivated p-type CQDs (pCQDs) have been the best...

In this paper, we present results from the detailed investigations on the synthesis, optical, emission, electrochemical, and ultrafast nonlinear optical (NLO) properties along with the excited stat...

Porphyrins are well-known anticancer agents because of their high binding affinity for G-quadruplex DNA and excellent photophysical properties. Several studies carried out using TMPyP4 established it as an efficient chemotherapeutic and a photodynamic therapeutic (PDT) agent, but its use as a lead molecule has been restricted because of its high level of binding to double-stranded DNA (dsDNA), which may have side effects on normal cells and tissues. To minimize its interaction with dsDNA and to enhance internalization into cells, an analogue of TMPyP4 (5Me) was synthesized. Its selectivity for G-quadruplex DNA over dsDNA was evaluated by spectroscopic methods, and its role in stabilizing G-quadruplex DNA was assessed by fluorescence lifetime and thermal melting experiments. Biophysical studies indicated that 5Me interacts well with G-quadruplex DNA. In vitro cytotoxicity experiments with tumor cell lines (PANC-1, B16F10, and MDA MB 231) have revealed that 5Me can inhibit the growth of cancer cells comparable to TMPyP4. MTT and apoptotic assays demonstrated the ability of 5Me to specifically affect cancer cells over normal cells. Cell cycle analysis showed that 5Me, like TMPyP4, induces G2/M phase cell cycle arrest. In addition, 5Me is more effectively taken up by both cancer and normal cells than TMPyP4. In addition, we have noticed that 5Me is more efficient than TMPyP4 in inhibiting the growth of the cancer cells after irradiation with light (600-720 nm, 20 J/cm

Origin of mixed valence states from π-conjugated photoresponsive systems offers self-assembled nanostructures facilitating excellent optoelectronic properties. Despite various electron-rich moieties, tethered linear π-conjugated systems generate charged ions however limited to standard redox-active materials until now, which further extended to macrocyclic systems. Herein, we report three carbazole and triphenylamine-assisted phthalocyanine derivatives (1, 2, and 3) and discussed the nature of photobleaching/photoionization by illumination with an excitation wavelength of 350 nm. Detailed UV–visible absorption and cyclic voltammetry studies revealed that three derivatives are bleached during irradiation; however, 3 exhibits mixed valence species in CHCl3 when compared to 1 and 2. Microscopic analysis suggested that ionized 3 forms nanospheres with an average diameter of 100–400 nm upon methanol vapor diffusion approach. Thus, photoresponsive mixed valence systems facilitated well-defined nanostructures, t...

In this study, a novel visible-light-driven photocatalyst was designed based on unsymmetrical zinc–phthalocyanine photosensitizer on hierarchical porous TiO2 (HPT) semiconductor. The HPT material has been prepared by a simple self-formation route. The present work successfully uses zinc phthalocyanine with spectral response extended to 700 nm triggers light harvesting center and HPT semiconductors for high photocatalytic H2 production. This novel unsymmetrical zinc–phthalocyanine (PCH001) containing three tert-butyl and two carboxylic acid groups that act as “push” and “pull” electron transfer properties from the excited dye to the TiO2 conduction band. The carboxylic group in the sensitizer serves as an anchoring group on to the surface of TiO2 and to provide intimate electronic coupling between its excited-state wave function and the conduction-band manifold of the semiconductor. The excellent photophysical properties was governed further by choosing three tert-butyl groups which tuned the LUMO level of...

Porphyrins are major sensitizers in dye-sensitized solar cells (DSSCs) and result in very high power conversion efficiency; however, aggregation tendency and visible range absorption prevent realistic applications. Thus, designing of novel porphyrins based sensitizers is essential to resolve the current existing issues. In this context, seven D−π–A porphyrin dyes (LG1–LG7) engineered with 3-ethynyl phenothiazine tethered at the meso-position and π-spacers, such as 4-ethynyl phenyl (LG1), 5-ethynylthiophene (LG2), 5-ethynyl furan (LG3), 2,1,3-benzothiadiazole (BTD)–phenyl (LG6), and BTD–thiophene (LG7), were incorporated between porphyrin macrocycle and anchoring carboxylic acid. Similarly, π-spacers 4-ethynyl phenyl (LG4) and 4-ethynylthiophene (LG5) were functionalized between porphyrin and anchoring cyanoacrylic acid. LG5 and LG6 showed significant near-infrared absorption resulting in the highest efficiency of 10.20% and 9.64% among other derivatives. UV–vis-NIR absorption, cyclic voltammetry, and dens...