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Conjugated polymers (CPs) have been developed quickly as an emerging functional material with applications in optical and electronic devices, owing to their highly electron‐delocalized backbones and versatile side groups for facile processibility, high mechanical strength, and environmental stability. CPs exhibit multistimuli responsive behavior and fluorescence quenching properties by incorporating azobenzene functionality into their molecular structures. Over the past few decades, significant progress has been made in developing functional azobenzene‐based conjugated polymers (azo‐CPs), utilizing diverse molecular design strategies and synthetic pathways. This article comprehensively reviews the rapidly evolving research field of azo‐CPs, focusing on the structural characteristics and synthesis methods of general azo‐CPs, as well as the applications of charged azo‐CPs, specifically azobenzene‐based conjugated polyelectrolytes (azo‐CPEs). Based on their molecular structures, azo‐CPs can be broadly categorized into three primary types: linear CPs with azobenzene incorporated into the side chain, linear CPs with azobenzene integrated into the main chain, and branched CPs containing azobenzene moieties. These systems are promising for biomedical applications in biosensing, bioimaging, targeted protein degradation, and cellular apoptosis. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) have gained considerable attention due to their potential applications in emerging biosensor platforms. The use of conjugated polyelectrolytes (CPEs) as active materials in OECTs is particularly advantageous owing to their functional, water‐processable, and biocompatible nature, as well as their tunable electronic and ionic transport properties. However, there exists a lack of systematic studies of the structure‐property relationships of these materials with respect to OECT performance. This study shows how by tuning the molecular weight of self‐doped CPE (CPE‐K) it is possible to fabricate OECTs with a µC* value of 14.7 F cm−1 V−1 s−1, one order of magnitude higher than previously reported CPE‐based devices. Furthermore, OECTs with a transconductance of 120 mS are demonstrated via device engineering. While CPE‐K batches with different molecular weights show good doping behavior and high volumetric capacitance, as confirmed by spectroelectrochemistry and electrochemical impedance spectroscopy, the medium molecular weight possesses the highest carrier mobility of ≈0.1 cm2 V−1 s−1 leading to the highest transconductance. The enhanced charge transport is due to a favorable charge percolation pathway, as revealed by the combination of X‐ray analysis and conductive atomic force microscope. These insights provide guidelines for further improving the performance of CPE‐based OECTs. [ABSTRACT FROM AUTHOR]

Polythiophene‐based conjugated polyelectrolytes (CPE) are attracting increasing attention as sensor or interface materials in chemistry and biology. While cationic polythiophenes are better understood, limited structural information is available on their anionic counterparts. Limited access to well‐defined polymers has made the study of structure‐property relationships difficult and clear correlations have remained elusive. By combining controlled Kumada catalyst transfer polymerization with a polymer‐analog substitution, regioregular and narrowly distributed poly(6‐(thiophen‐3‐yl)hexane‐1‐sulfonate)s (PTHS) with tailored chain length are prepared. Analysis of their aqueous solution structures by small‐angle neutron scattering (SANS) revealed a cylindrical conformation for all polymers tested, with a length close to the contour length of the polymer chains, while the estimated radii remain too small (<1.5 nm) for extensive π‐stacking of the chains. The latter is particularly interesting as the longest polymer exhibits a concentration‐independent structured absorption typical of crystalline polythiophenes. Increasing the ionic strength of the solution diminishes these features as the Coulomb repulsion between the charged repeat units is shielded, allowing the polymer to adopt a more coiled conformation. The extended π‐conjugation, therefore, appears to be a key parameter for these unique optical features, which are not present in the corresponding cationic polythiophenes. [ABSTRACT FROM AUTHOR]

For an ideal electron interlayer, both electron injection and hole‐blocking properties are important to achieve better polymer light‐emitting devices (PLEDs) performance. Conjugated polyelectrolytes (CPEs) are applied widely in PLEDs to enhance charge injection. Understanding the role of backbone structures and energetic matching between the CPEs and emitters can benefit charge injection and balance. Herein, a postpolymerization approach to introduce varying amounts of alkyl sulfonate groups onto the backbone of a copolymer of 5‐fluoro‐2,1,3‐benzothiadiazole and 9,9′‐dioctylfluorene is utilized. This study finds that device performance is dependent on the percentage of sulfonate groups incorporated, with the optimal copolymer (CPE‐50%) maintaining efficient ohmic electron injection and gaining enhanced hole‐blocking properties, thereby achieving the most balanced hole/electron current. Therefore, the PLED with CPE‐50% interlayer exhibits the highest efficiency (20.3 cd A−1, 20.2 lm W−1) and the fastest response time (4.3 µs), which is the highest efficiency among conventional thin (70 nm) F8BT PLEDs with CPEs. These results highlight the importance of balanced charge carrier density in CPEs and highlight that postpolymerization modification is a useful method for fine‐tuning ionic content. [ABSTRACT FROM AUTHOR]

The use of conjugated polyelectrolytes (CPEs) as interfacial layers (ILs) to increase the efficiency of organic light‐emitting diodes (OLEDs), organic solar cells (OSCs), and organic transistors is a well‐established strategy. Here, the rational process is reported that led to develop the bifunctional poly[(2,7‐(9,9'‐bis(6'‐diethoxylphosphorylhexyl)‐fluorene)‐alt‐(2,7‐(9,9′‐bis(6″‐trimethylammonium bromide)hexyl)‐fluorene)] (PF‐NBr‐EP). PF‐NBr‐EP is successfully incorporated as a cathode IL (CIL) in diverse electronic and optoelectronic devices. The properties of two fluorene‐based CPEs containing, respectively, phosphonate (EP) and ammonium (NBr) moieties used as building blocks for the synthesis of the PF‐NBr‐EP copolymer and their mixtures are investigated to evaluate the combined effect of the two moieties and therefore to gain insight into the behavior of PF‐NBr‐EP chemical structure in the devices. Additionally, the performance of OLEDs and OSCs is analyzed based on established active layers, incorporating all these neat and mixed CILs. [ABSTRACT FROM AUTHOR]

The electron transport layer (ETL) is a critical component in achieving high device performance and stability in organic solar cells. Conjugated polyelectrolytes (CPEs) have become an attractive alternative due to film‐forming properties and ease of preparation. However, p‐type CPEs generally exhibit poor charge mobility and conductivity, incorporation of electron‐withdrawing units forming alternated D‐A conjugated backbone can make up for these deficiencies. Herein, the ratio of electron withdrawing moieties are further increased and two poly(A1‐alt‐A2) typed PIIDNDI‐Br and PDPPNDI‐Br based on the combination of naphthalene diimide (NDI) with isoindigo (IID) or diketopyrrolopyrrole (DPP) via direct arylation polycondensation are synthesized. These CPEs possess excellent alcohol solubility, a suitable lowest unocuppied molecular orbital energy level, and work function tunability. Surprisingly, the incorporation of IID and DPP units generate distinct self‐doping behaviors, which are confirmed by UV–vis absorption and ESR spectra. However, no matter doped or undoped, both CPEs present better charge‐transporting properties and conductivity when utilized as ETLs. The PIIDNDI‐Br and PDPPNDI‐Br display good universal compatibility with the blend of PM6:Y6 and PM6:L8‐BO, and PCEs of 18.32% and 18.36% are obtained, respectively, which also present excellent storage stability. In short, the combination of two different acceptors demonstrates an efficient strategy to design highly efficient ETLs for high performance photovoltaic devices. [ABSTRACT FROM AUTHOR]

Bioelectrochemical systems hold the promise of enabling sustainable microbial‐mediated energy interconversion between electrical and chemical energy. Herein, it is demonstrated how a single conjugated polymer can be used to enhance bidirectional extracellular electron transfer through forming self‐assembled coatings on individual cells. Specifically, the n‐type conjugated polyelectrolyte p(cNDI‐gT2) exhibits a reduction potential window between −0.1 and −0.8 V (vs Ag/AgCl), thereby driving thermodynamically favored electron transfer in both directions across the abiotic‐biotic interface that involves the outer membrane cytochromes and flavins of Shewanella oneidensis MR‐1. Electrochemical tests show that injection from an external electrode into Shewanella oneidensis MR‐1 is enabled at negative potentials (−0.6 V), while electron extraction is possible at positive potentials (0.2 V). Relative to controls, the biohybrid shows a sixfold increase in biocurrent generation and a 35‐fold increase in current uptake for the bioelectrosynthesis of succinate from fumarate. This demonstrated abiotic‐biotic synergy provides new strategies for designing multifunctional biohybrids. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolytes (CPEs) comprised of conjugated backbones and pendant ionic functionalities are versatile organic semiconductors with myriad optoelectronic applications. Although polarons are dominant charge carriers in conducting CPEs owing to strong electron‐phonon coupling, their properties are not well understood, especially from a first‐principles perspective. In this study, a comprehensive study on the stability, structural deformation, electronic structure, and optical absorption of positive (or hole)/negative (or electron) polarons and bi‐polarons in CPEs is conducted. It is explored how these properties depend on the electrostatic interaction between the polarons and ionic functionalities, including alkyl chains, ionic groups, and counterions. It is then examined how the bandgap, polaron binding energy, and optoelectronic structure of CPEs can be tuned by various combinations of the donor and acceptor units in their backbones. Finally, electrochemical stability of CPEs is studied and light is shed on the absence of negative polarons in CPEs. The strategy to improve the electrochemical stability of n‐doped CPEs is also discussed. [ABSTRACT FROM AUTHOR]

Due to their distinctive intrinsic advantages, the nanoaggregates of conjugated polyelectrolytes (CPEs) are fascinating and attractive for various luminescence applications. Generally, the emission luminescence of CPEs is determined by the conjugated backbone structure, i.e., different conjugated backbones of CPEs produce emission luminescence with different emission wavelength bands. Here, we polymerized the bis(boronic ester) of benzothiadiazole and an alkyl sulfonate sodium-substituted dibromobenzothiatriazole to provide PBTBTz-SO3Na with different molecular weights via controlling the ratio of the monomer and the catalyst. Theoretically, the CPEs with the same molecular structure usually display similar photoelectronic performances. However, the resulting PBTBTz-SO3Na reveal a similar light absorption property, but different luminescence. The higher molecular weight is, the stronger the fluorescence intensity of PBTBTz-SO3Na that occurs. PBTBTz-SO3Na with different molecular weights have different colors of luminescence. It is well known that the molecular aggregates often led to weaker luminescent properties for most of the conjugated polymers. However, PBTBTz-SO3Na exhibits a higher molecular weight with an increasing molecular chain aggregation, i.e., the nanoaggregates of PBTBTz-SO3Na are beneficial to emission luminescence. This work provides a new possible chemical design of CPEs with a controllable, variable luminescence for further optoelectronics and biomedicine applications. [ABSTRACT FROM AUTHOR]

Successful practical implementation of bioelectrochemical systems (BES) requires developing affordable electrode structures that promote efficient electrical communication with microbes. Recent efforts have centered on immobilizing bacteria with organic semiconducting polymers on electrodes via electrochemical methods. This approach creates a fixed biocomposite that takes advantage of the increased electrode's electroactive surface area (EASA). Here, it is demonstrated that a biocomposite comprising the water‐soluble conjugated polyelectrolyte CPE‐K and electrogenic Shewanella oneidensis MR‐1 can self‐assemble with carbon paper electrodes, thereby increasing its biocurrent extraction by ≈6‐fold over control biofilms. A ≈1.5‐fold increment in biocurrent extraction is obtained for the biocomposite on carbon paper relative to the biocurrent extracted from gold‐coated counterparts. Electrochemical characterization revealed that the biocomposite stabilized with the carbon paper more quickly than atop flat gold electrodes. Cross‐sectional images show that the biocomposite infiltrates inhomogeneously into the porous carbon structure. Despite an incomplete penetration, the biocomposite can take advantage of the large EASA of the electrode via long‐range electron transport. These results show that previous success on gold electrode platforms can be improved when using more commercially viable and easily manipulated electrode materials. [ABSTRACT FROM AUTHOR]

A facile synthesis of low band gap water soluble dyad materials comprising of fullerenol and poly thiophene carboxylic acids is demonstrated. Fullerene‐conjugated polyelectrolytes dyad materials were prepared using polythiophene‐3‐acetic acid (PT3AA) and polythiophene‐3‐malonic acid (PT3MA) as donors and fullerenol as acceptor in microwave synthesizer at 70°C. The reaction has several advantages over conventional reflux methods; easy to handle, fast reaction and good quality products. Fullerene core star‐like dyad structures having single‐ or di‐carboxylic acid group in each thiophene ring were synthesized. Thermal methods (TGA & DSC) estimated about six to seven exohedrally attached polymer units to fullerene core. The electrochemical band gaps of ~1.17 and 1.21 eV were recorded for fullerenol poly thiophene 3‐acetic acid (FPT3AA) and fullerenol polythiophene‐3‐malonic acid (FPT3MA) dyads, respectively. The UV–vis analyses record a red shifting of absorbance maxima for mono carboxylic acid (408 nm FPT3AA vs. 263 nm PT3AA) and blue shifting in di‐carboxylic acid (263 nm FPT3MA vs. 396 nm PT3MA). The strong quenching and substantial red shifting of emission peaks of dyad materials compared to both fullerenol and polymers demonstrate charge transfer exciplex formation in excited state. [ABSTRACT FROM AUTHOR]

The ability to assemble artificial systems that mimic aspects of natural light‐harvesting functions is fascinating and attractive for materials design. Given the complexity of such a system, a simple design pathway is desirable. Here, we argue that associative phase separation of oppositely charged conjugated polyelectrolytes (CPEs) can provide such a path in an environmentally benign medium: water. We find that complexation between an exciton–donor and acceptor CPE leads to formation of a complex fluid. We interrogate exciton transfer from the donor to the acceptor CPE within the complex fluid and find that transfer is highly efficient. We also find that excess molecular ions can tune the modulus of the inter‐CPE complex fluid. Even at high ion concentrations, CPEs remain complexed with significantly delocalized electronic wavefunctions. Our work lays the rational foundation for complex, tunable aqueous light‐harvesting systems via the intrinsic thermodynamics of associative phase separation. [ABSTRACT FROM AUTHOR]

The ability to assemble artificial systems that mimic aspects of natural light‐harvesting functions is fascinating and attractive for materials design. Given the complexity of such a system, a simple design pathway is desirable. Here, we argue that associative phase separation of oppositely charged conjugated polyelectrolytes (CPEs) can provide such a path in an environmentally benign medium: water. We find that complexation between an exciton–donor and acceptor CPE leads to formation of a complex fluid. We interrogate exciton transfer from the donor to the acceptor CPE within the complex fluid and find that transfer is highly efficient. We also find that excess molecular ions can tune the modulus of the inter‐CPE complex fluid. Even at high ion concentrations, CPEs remain complexed with significantly delocalized electronic wavefunctions. Our work lays the rational foundation for complex, tunable aqueous light‐harvesting systems via the intrinsic thermodynamics of associative phase separation. [ABSTRACT FROM AUTHOR]

Conducting polymer hydrogels (CPHs) are an attractive class of materials that synergize the electrical properties of organic semiconductors with the physical properties of hydrogels. Of particular interest is the implementation of CPHs as electrode materials for electrochemical energy storage by taking advantage of redox‐tunable conjugated backbones and the large electroactive surface area. Herein, the use of 2D electrolytes as an effective post‐polymerization additive to enhance the pseudocapacitive performance of CPHs, is demonstrated. By using the self‐doped conjugated polyelectrolyte CPE‐K hydrogel as a model system, improvements in cycling stability, specific capacitance and working voltage window upon addition of the 2D electrolytes, are shown. Furthermore, positively charged 2D electrolytes to be more effective than their negatively charged counterparts are revealed. Rheology measurements and SEM imaging indicate that the 2D electrolytes serve as non‐covalent cross‐linkers that help in forming a mechanically more robust and highly percolated conducting network. These results provide a new and simple to execute post‐polymerization strategy to optimize the electrochemical performance of CPH‐based pseudocapacitors. [ABSTRACT FROM AUTHOR]

The development of luminescent materials is critical to humankind. The Nobel Prizes awarded in 2008 and 2010 for research on the development of green fluorescent proteins and super-resolved fluorescence imaging are proof of this (2014). Fluorescent probes, smart polymer machines, fluorescent chemosensors, fluorescence molecular thermometers, fluorescent imaging, drug delivery carriers, and other applications make fluorescent polymers (FPs) exciting materials. Two major branches can be distinguished in the field: (1) macromolecules with fluorophores in their structure and (2) aggregation-induced emission (AIE) FPs. In the first, the polymer (which may be conjugated) contains a fluorophore, conferring photoluminescent properties to the final material, offering tunable structures, robust mechanical properties, and low detection limits in sensing applications when compared to small-molecule or inorganic luminescent materials. In the latter, AIE FPs use a novel mode of fluorescence dependent on the aggregation state. AIE FP intra- and intermolecular interactions confer synergistic effects, improving their properties and performance over small molecules aggregation-induced, emission-based fluorescent materials (AIEgens). Despite their outstanding advantages (over classic polymers) of high emission efficiency, signal amplification, good processability, and multiple functionalization, AIE polymers have received less attention. This review examines some of the most significant advances in the broad field of FPs over the last six years, concluding with a general outlook and discussion of future challenges to promote advancements in these promising materials that can serve as a springboard for future innovation in the field. [ABSTRACT FROM AUTHOR]

Phosphonium‐based polythiophene conjugated polyelectrolytes (CPEs) with three different counterions (dodecylsulfate, octylsulfate and perfluorooctane sulfonate) are synthesized to determine how the nature of the counterion affects the thermal properties, the self‐assembly in thin films and the performance as the cathode interfacial layer in polymer solar cells (PSCs). The counterion has a significant effect on the thermal properties of the CPEs, affecting both their glass transition and crystalline behaviour. Grazing‐incidence wide‐angle X‐ray scattering studies also indicate that changing the nature of the counterion influences the microstructural organization in thin films (face‐on versus edge‐on orientation). The affinity of the CPEs with the underlying photoactive layer in PSCs is highly correlated with the counterion species. Finally, in addition to an increase of the power conversion efficiency of ca 15% when using these CPEs as cathode interfacial layers in PSCs, a higher device stability is noted, compared to a reference device with a calcium interlayer. © 2020 Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]

Fluorescence imaging using poly(phenylene ethynylene) (PPE) based conjugated polyelectrolytes (CPEs) has garnered considerable attention in the recent past due to their remarkable photophysical properties. In this report, we studied the fluorescence imaging properties of a set of six PPE‐based CPEs appended with side chains varying in structure and number of cationic charges. The photophysical and aggregation features of the CPEs depend on the overall charge density on the polymer in water. The cytotoxicity of the CPEs was evaluated against MCF‐7 mammalian cells, which revealed that polyelectrolytes with less cationic charge are less cytotoxic and vice versa. Confocal laser scanning microscopy (CLSM) studies showed that all the CPEs could efficiently penetrate into the MCF‐7 cells after 10 h of incubation. The transit of CPEs into the lysosomes was confirmed by comparison with the uptake of LysoTracker Red DND‐99 dye, which also revealed that the polyelectrolytes are highly photostable. We also demonstrated that the imidazolium‐functionalized CPEs could selectively stain bacteria over mammalian cells, suggesting the importance of CPEs for clinical applications. [ABSTRACT FROM AUTHOR]

Doping provides an efficient strategy to control the electronic properties of organic semiconductors. However, compared with the widely reported p‐type doping protocols, n‐type doping of organic semiconductors still remains a challenge. Herein, a series of novel n‐doped conjugated polyelectrolytes (CPEs) with high doping levels and conductivity are designed. These CPEs are synthesized via a facile, metal‐free, and high‐yield aldol condensation protocol from bis‐isatin and bis‐oxindole monomers. The designed CPEs possess a n‐type electron‐deficient and rigid conjugated backbone, resulting in easy charge delocalization, enhanced n‐doping behaviors, and high conductivity. The evolution on the counterions of these CPEs further alters their n‐doping behaviors, charge transporting properties, and work function tunability, etc. By using these CPEs as electron transport materials (ETMs) for nonfullerene polymer solar cells (NF–PSCs), high power conversion efficiencies (PCEs) over 16% can be achieved when PM6:Y6 is used as the active component. Moreover, these CPEs can enable efficient NF–PSCs even if their thicknesses are up to 60 nm, indicating the potential of these CPEs as thickness‐insensitive ETMs for the fabrication of large‐area NF–PSCs. [ABSTRACT FROM AUTHOR]

Robust photosensitizers with strong red/NIR fluorescence, efficient reactive oxygen species (ROS) generation and high photostability are highly desired for photodynamic therapy (PDT). Herein, three novel red conjugated polyelectrolytes (CPEs) with tetraphenylethene and 2,1,3-benzothiadiazole on the main chains and triphenylphosphonium on the side chains are developed. These CPEs display apparent aggregation-induced emission feature and high fluorescence quantum yields in the aggregated state. They can target lysosome in HeLa cells for fluorescence bioimaging. By virtue of the good retention effect and high photostability, these CPEs show ultralong-term tracing performance of subcutaneous tumors, and the tumor site can still be visualized for 20 days after injection. Owing to their good biocompatibility and strong ROS generation ability, the image-guided PDT based on these CPEs can effectively inhibit the growth of subcutaneous tumor and significantly prolong the survival of tumor bearing mice. The H&E and IHC staining reveal that the PDT of these CPEs depress the proliferation of tumor cells, and promote apoptosis and necrosis process. These new CPEs may be employed both as fluorescent probes for in vitro and in vivo long-term tracing and as photosensitizers for image-guided PDT of tumors. [ABSTRACT FROM AUTHOR]

The use of π‐conjugated polymers (CPs) in conductive hydrogels remains challenging due to the water‐insoluble nature of most CPs. Conjugated polyelectrolytes (CPEs) are promising alternatives because they have tunable electronic properties and high water‐solubility, but they are often difficult to synthesize and thus have not been widely adopted. Herein, we report the synthesis of an anionic poly(cyclopentadienylene vinylene) (aPCPV) from an insulating precursor under mild conditions and in high yield. Functionalized aPCPV is a highly water‐soluble CPE that exhibits low cytotoxicity, and we found that doping hydrogels with aPCPV imparts conductivity. We also anticipate that this synthetic strategy, due to its ease and high efficiency, will be widely used to create families of not‐yet‐explored π‐conjugated vinylene polymers. [ABSTRACT FROM AUTHOR]

The use of π‐conjugated polymers (CPs) in conductive hydrogels remains challenging due to the water‐insoluble nature of most CPs. Conjugated polyelectrolytes (CPEs) are promising alternatives because they have tunable electronic properties and high water‐solubility, but they are often difficult to synthesize and thus have not been widely adopted. Herein, we report the synthesis of an anionic poly(cyclopentadienylene vinylene) (aPCPV) from an insulating precursor under mild conditions and in high yield. Functionalized aPCPV is a highly water‐soluble CPE that exhibits low cytotoxicity, and we found that doping hydrogels with aPCPV imparts conductivity. We also anticipate that this synthetic strategy, due to its ease and high efficiency, will be widely used to create families of not‐yet‐explored π‐conjugated vinylene polymers. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen evolution is viewed as a promising green strategy to utilize the inexhaustible solar energy and provide clean hydrogen fuels with zero‐emission characteristic. The nature of semiconductor‐based photocatalysts is the key point to achieve efficient photocatalytic hydrogen evolution. Conjugated materials have been recently emerging as a novel class of photocatalysts for hydrogen evolution and photocatalytic reactions due to their electronic properties can be well controlled via tailor‐made chemical structures. Hydrophilic conjugated materials, a subgroup of conjugated materials, possess multiple advantages for photocatalytic applications, thus spurring remarkable progress on both material realm and photocatalytic applications. This minireview aims to provide a brief review of the recent developments of hydrophilic conjugated polymers/small molecules for photocatalytic applications, and special concern on the rational molecular design and their impact on photocatalytic performance will be reviewed. Perspectives on the hydrophilic conjugated materials and challenges to their applications in the photocatalytic field are also presented. [ABSTRACT FROM AUTHOR]

Robust photosensitizers with strong red/NIR fluorescence, efficient reactive oxygen species (ROS) generation and high photostability are highly desired for photodynamic therapy (PDT). Herein, three novel red conjugated polyelectrolytes (CPEs) with tetraphenylethene and 2,1,3-benzothiadiazole on the main chains and triphenylphosphonium on the side chains are developed. These CPEs display apparent aggregation-induced emission feature and high fluorescence quantum yields in the aggregated state. They can target lysosome in HeLa cells for fluorescence bioimaging. By virtue of the good retention effect and high photostability, these CPEs show ultralong-term tracing performance of subcutaneous tumors, and the tumor site can still be visualized for 20 days after injection. Owing to their good biocompatibility and strong ROS generation ability, the image-guided PDT based on these CPEs can effectively inhibit the growth of subcutaneous tumor and significantly prolong the survival of tumor bearing mice. The H&E and IHC staining reveal that the PDT of these CPEs depress the proliferation of tumor cells, and promote apoptosis and necrosis process. These new CPEs may be employed both as fluorescent probes for in vitro and in vivo long-term tracing and as photosensitizers for image-guided PDT of tumors. [ABSTRACT FROM AUTHOR]

Interface engineering is an effective means to enhance the performance of thin‐film devices, such as perovskite solar cells (PSCs). Herein, a conjugated polyelectrolyte, poly[(9,9‐bis(3′‐((N,N‐dimethyl)‐N‐ethyl‐ammonium)‐propyl)‐2,7‐fluorene)‐alt‐2,7‐(9,9‐dioctylfluorene)]di‐iodide (PFN‐I), is used at the interfaces between the hole transport layer (HTL)/perovskite and perovskite/electron transport layer simultaneously, to enhance the device power conversion efficiency (PCE) and stability. The fabricated PSCs with an inverted planar heterojunction structure show improved open‐circuit voltage (Voc), short‐circuit current density (Jsc), and fill factor, resulting in PCEs up to 20.56%. The devices maintain over 80% of their initial PCEs after 800 h of exposure to a relative humidity 35–55% at room temperature. All of these improvements are attributed to the functional PFN‐I layers as they provide favorable interface contact and defect reduction. [ABSTRACT FROM AUTHOR]

Poly(6‐(4,7‐dimethyl‐2H‐benzo[d][1,2,3]triazol‐2‐yl)‐N,N,N‐trimethylhexan‐1 aminium iodide) (PBTz‐TMAI) and poly(sodium 4‐(4,7‐dimethyl‐2H‐benzo[d] [1,2,3]triazol‐2‐yl)butane‐1‐sulfonate) (PBTz‐SO3Na) based on the same benzotriazole‐conjugated backbone but with ammonium and sulfonated side chains are designed and synthesized through side‐chain functionalization and Yamamoto polymerization, respectively, and are used as the cathode interlayers in fullerene‐ and non‐fullerene‐based polymer solar cells. The interfacial modification of PBTz‐TMAI and PBTz‐SO3Na onto the active layer achieves good energy alignment at cathode electrodes and optimized exciton‐dissociation efficiency from the active layer. Consequently, the power conversion efficiencies (PCEs) of 7.8% and 9.6% are obtained for the fullerene PTB7:PC71BM‐based and non‐fullerene PBDB‐T:ITIC‐based polymer solar cells (PSCs) with PBTz‐SO3Na interlayer. The PCS devices based on PTB7:PC71BM and PBDB‐T:ITIC active layers with PBTz‐TMAI interlayer achieved a remarkably improved performance with PCEs of 8.2% and 10.2%, respectively. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolytes based on benzotriazole (BT) and benzothiadiazole (BTz) alt unit with a pendant sulfonate ion but different countercations were synthesized and named PBTBTz-SO3Na and PBTBTz-SO3TBA. PBTBTz-SO3Na was used as a cathode interface applied to polymer solar cells (PSCs), and ITO/PEDOT:PSS/active layer/cathode interlayer/Al was set as a device structure. The PSCs displayed an average power conversion efficiency (PCE) of 7.7%, revealing an unchanged efficiency in comparison with that of the control device fabricated from a CH3OH interlayer. TBA+, a different counteraction, was used instead of Na+ to further study the influence of counterions on the electrical property of PBTBTz-SO3−. PBTBTz-SO3TBA was used as a cathode interface to fabricate two types of PSCs based on PTB7:PC71BM and PBDB-T:ITIC, and their improved average PCEs were 8.6% and 9.1%, respectively. [ABSTRACT FROM AUTHOR]

Two novel poly(pyridinylene vinylene) (PPV)-type conjugated polyelectrolytes 2,6-PPYPV-(2+) and 3,5-PPYPV-(2+) were synthesized via Heck coupling reaction and characterized by 1H nuclear magnetic resonance (NMR), ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy. The two polymers consisting of meta-position substituted pyridinylenes as the metal recognition unit and a water-soluble divinyl-benzene derivative in the backbones. 2,6-PPYPV-(2+) and 3,5-PPYPV-(2+) both exhibit strongest fluorescence in methanol and weakest fluorescence in water among common polar solvents. In respect of ion detection, 3,5-PPYPV-(2+) has an excellent identifiability for Pd2+ in methanol with the K_SV value of 1.1×105m−1 while 2,6-PPYPV-(2+) has a good selectivity for Cu2+ and Hg2+ in aqueous solution. And all the Stern-Volmer plots of 2,6-PPYPV-(2+) and 3,5-PPYPV-(2+) in fluorescence quenching for metal ions have favorable tendencies. All the results suggest that 2,6-PPYPV-(2+) and 3,5-PPYPV-(2+) are promising materials in the applications of high performance chemosensors for some specific metal ions. [ABSTRACT FROM AUTHOR]

Abstract: Here, a means of controlling the assembly pathways of p‐conjugated oligoelectrolytes into supramolecular fibers and microtubes is presented, and it is shown how the addition of small end‐caps to well‐defined and pH‐responsive conjugated oligomers can alter the balance between repulsive and attractive supramolecular forces and enables control of the morphology of the hierarchical assembly process. The assembly stages from nuclei to protofibers are evidenced and a hypothesis on the mechanism of microtubes formation using a combination of analytical methods is provided, revealing different degrees of order at different scales along the structural hierarchy. [ABSTRACT FROM AUTHOR]

Abstract: Three complexes of gadolinium‐based on dentritic molecules are reported as magnetic resonance imaging (MRI) contrast agents. Their ligands feature four carboxylate groups, which contribute to good water solubility and a strong combination with metal ions. As a new attempt, coupling polymerization is carried out to make a combination of conjugated polyelectrolytes and dendrimers for MRI contrast agents. For comparison, mononuclear and binuclear complexes are also reported. The investigation suggests that the contrast agent with the newly designed macromolecular skeleton provides higher longitudinal relaxivity value (36.2 m m −1s−1) and more visible enhancement in in vivo and in vitro MR images than the small molecular ones. In addition, extremely low cytotoxicity and main clearance via hepatobiliary are confirmed, which reduces the deterioration of chronic kidney disease. All the results indicate that these three complexes are generally applicable as promising clinical contrast agents. [ABSTRACT FROM AUTHOR]

Theoretical calculation study of two alternating conjugated polyelectrolytes, named SDPP-PPV and SDPP-PPE, constituted of 1,4-diketo-2,5-bis(4-sulfonylbutyl)- 3,6-bis(4-bromophenyl) pyrrolo[3,4-c]pyrrole (SDPP) with 2,5-diethoxy-1,4-phenylenevinylene (DVB) or 2,5-diethoxy-1,4-phenyleneethynylene (DEB) were carried out with Gaussian 09 software. The absorption spectral study shows that SDPP-PPV and SDPP-PPE have broad coverage of visible spectra and considerable red shift compared with water-soluble poly(p-phenylenevinylene)s (PPVs) and poly(p-phenyleneethynylene)s (PPEs). The TD-DFT calculation results show that LUMO of the polymers can be significantly reduced and the HOMO-LUMO gap can be changed by introducing DPP into the backbone. Theoretical study indicates that introduction of electro-deficient unit DPP in the polymer main chain can optimize the band structure of traditional PPV and PPE. The improved optical properties and excellent water solubility of these two novel DPP-based conjugated polyelectrolytes allow them to be promising materials in optoelectronic applications. [ABSTRACT FROM AUTHOR]

Three anionic fluorene-based alternating conjugated polyelectrolytes (CPEs) have been synthesized that have 9,9-bis(4-phenoxy-butylsulfonate) fluorene-2,7-diyl and 1,4-phenylene (PBS-PFP), 4,40-biphenylene (PBS-PFP2), or 4,400-p-terphenylene (PBS-PFP3) groups, and the effect of the length of the oligophenylene spacer on their aggregation and photophysics has been studied. All form metastable dispersions in water, but can be solubilized using methanol, acetonitrile, or dioxane as cosolvents. This leads to increases in their emission intensities and blue shifts in fluorescence maxima due to break-up of aggregates. In addition, the emission maximum shifts to the blue and the loss of vibronic structure are observed when the number of phenylene rings is increased. Debsity Functional Theory (DFT) calculations suggest that this is due to increasing conformational flexibility as the number of phenylene rings increases. This is supported by increasing amplitude in the fast component in the fluorescence decay. The nonionic surfactant n-dodecylpentaoxyethylene glycol ether (C12E5) also breaks up aggregates, as seen by changes in fluorescence intensity and maximum. However, the loss in vibrational structure is less pronounced in this case, possibly due to a more rigid environment in the mixed surfactant-CPE aggregates. Further information on the aggregates formed with C12E5 was obtained by electrical conductivity measurements, which showed an initial increase in specific conductivity upon addition of surfactants, while at higher surfactant/CPE molar ratios a plateau was observed. The specific conductance in the plateau region decreased in the order PBS-PFP3 < PBS-PFP2 < PBS-PFP, in agreement with the change in charge density on the CPE. The reverse process of aggregate formation has been studied by injecting small volumes of solutions of CPEs dissolved at the molecular level in a good solvent system (50% methanol-water) into the poor solvent, water. Aggregation was monitored by changes in both fluorescence and light scattering. The rate of aggregation increases with hydrophobicity and concentration of sodium chloride but is only weakly dependent on temperature. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolytes (CPEs) are a focus of research because combine their inherent electrical conductivity and the ability to interact with ions in aqueous solutions or biological systems. However, it is still not understood to what degree the counter ion in CPEs influences the properties of the CPE itself and the performance of electronic transducers. In order to investigate this, three different conjugated polyelectrolytes, poly(6-(thiophen-3-yl)hexane- 1-sulfonate)s (PTHS--X+), are synthesized, which have the same polythiophene backbone but different X+ counter ions: the bulky tetrabutylammonium (TBA+), tetraethylammonium (TEA+), and the smallest tetramethylammonium (TMA+). At the interface with biological systems, thin CPE films have to be stable in an aqueous environment and should allow the inward and outward flow of ions from the electrolyte. Since the studied PTHS--X+ have different solubilities in water, the optical properties of pristine PTHS--X+ as well as of crosslinked PTHS--X+ via UV--vis absorption spectroscopy are investigated additionally. PTHS--TMA+ exhibits better aggregation, fast interdiffusion of ions, and fast recovery from the oxidized state. Additionally, spectroelectrochemical and cyclic voltammetric as well as electrochemical capacitance investigations show that PTHS--TMA+ can be oxidized to a higher degree. This leads to a better performance of PTHS--TMA+-based organic electrochemical transistors. [ABSTRACT FROM AUTHOR]

We probe anaerobic respiration of bacteria in the presence of conjugated polyelectrolytes (CPEs). Three different CPEs were used to probe how structural variations impact biocurrent generation from Shewanella oneidensis MR-1. For the self-doped anionic CPE only, absorption spectroscopy shows that the addition of S. oneidensis MR-1 leads to the disappearance of the polaron (radical cation) band at >900 nm and an increase in the band at 735 nm due to the neutral species, consistent with electron transfer from microbe to polymer. Microbial three-electrode electrochemical cells (M3Cs) show an increase in the current generated by S. oneidensis MR-1 with addition of the self-doped CPE relative to other CPEs and controls. These experiments combined with in situ cyclic voltammetry suggest that the doped CPE facilitates electron transport to electrodes and reveal structure-function relationships relevant to developing materials for biotic/abiotic interfaces. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolytes (CPEs) are polymer semiconductors whose properties are affected by the presence of covalently fixed and mobile ions. These structural components lead to interfacial dipoles, electrochemical doping, and mixed ionic and electronic conductivity. While the behavior of ionic carriers is important to a number of CPE applications, it remains difficult to quantify ion transport in films due to interference from electronic carriers; relationships between molecular structure and ion conductivity are thus not well understood. This work demonstrates direct observation of ions in six different CPE films using Kelvin probe force microscopy. Surface potential measurements of thin, planar CPE device structures are used to map the distribution of ions through the simple electrostatic relationship between potential and charge density. The transport of mobile ions within the CPE bulk can be studied through the time‐dependent relaxation of bias‐stressed CPE films, through which the decay of ion populations near each electrode is measured and carefully modeled, leading to estimated values of ionic mobility and effective ionic carrier density. The results show that ion transport is most strongly impacted by the number of ion‐bearing side chains per monomer, which facilitate room temperature ion transport via vibrational motion. [ABSTRACT FROM AUTHOR]

The article offers information on charge carriers in conjugated polyelectrolyte (CPE). Topics discussed include optoelectronic features of organic semiconductors with the ability of polyelectrolytes to modulate physical properties through electrostatic forces; injection barriers in organic optoelectronic devices; and the information on the Hall effect, Seebeck coefficient, field effect transistors (FETs), and ultraviolet photoelectron spectroscopy (UPS) measurements.

We measure the UV-visible absorption of an annealed hydrophobic conjugated polyelectrolyte as a function of the pH, for different temperatures and ionic strengths. The position of the absorption maximum shifts non-monotonically as the neutralization degree f decreases from 1 to 0, thus defining two regimes. In the hydrophilic regime, 1>f>f1, the red shift is due to dominant direct Coulombic interactions between the charges along the backbone and the ? electrons, without significant conformational effects. In the hydrophobic regime,f1>f>0, the blue shift is dominated by conformational effects with two successive isosbestic points as f decreases. We propose two possible scenarios for the collapse of the chains at low neutralization degrees. [ABSTRACT FROM AUTHOR]

Poly(Phenylene vinylene) anionic polyelectrolyte (PVBT‐SO3) was found to be an efficient hole extraction layer for inverted perovskite solar cells. It can be cast from an aqueous solution and does not require thermal annealing for improved device performance. The devices show maximum solar cell efficiency of 15.9% and exhibit improved stability under ambient conditions and enhanced charge extraction. [ABSTRACT FROM AUTHOR]

In this work, a multifunctional platform based on the versatile function of cationic poly( p-phenylene vinylene) (PPV) derivative has been developed for white light-enhanced siRNA delivery in a remote control manner. Conjugated polyelectrolyte PPV, which possesses cationic and amphipathic features, can effectively self-assemble with siRNA and deliver siRNA into living cells. More importantly, PPV can sensitize surrounding oxygen into reactive oxygen species (ROS) upon exposure to white light and disrupt the endosomal membrane, and the resulting enhanced endosomal escape increases the gene silencing ability of siRNA. Besides, due to high fluorescent emission, PPV can also be used to image the siRNA delivery and intracelluar location. Therefore, by taking full advantage of PPV, this strategy provides a new enhanced siRNA delivery in a non-invasive and spatiotemporal photochemical manner. [ABSTRACT FROM AUTHOR]

A series of anionic self-doped conjugated polyelectrolytes (CPEs) by copolymerization of a 1,4-bis(4-sulfonatobutoxy)benzene moiety with different counter monomers of thiophene, bithiophene, and terthiophene is reported. The CPEs show high conductivity of ≈10−4 S cm−1 due to being self-doped in a neutral state and exhibit excellent hole transporting property in the out-of-plane direction, compared with poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS). Moreover, the CPE incorporating a less electron-donating unit from terthiophene to thiophene exhibits a higher work function and therefore, PhNa-1T incorporating thiophene shows a relatively high work function of 5.21 eV than 4.97 eV of PEDOT:PSS. This can induce a higher internal field in the solar cell device, facilitating efficient charge collection to the electrode. As a result, polymer solar cell devices incorporating the CPEs as a hole transporting layer achieve enhanced photovoltaic performances from those of the conventional PEDOT:PSS-based devices. The solar cell efficiency reaches up to 9.89%, which is among the highest values demonstrated by PCE-10-based normal-type organic solar cells. [ABSTRACT FROM AUTHOR]

Low-temperature solution-processed high-efficiency colloidal quantum dot (CQD) photovoltaic devices are developed by improving the interfacial properties of p-n heterojunctions. A unique conjugated polyelectrolyte, WPF-6-oxy-F, is used as an interface modification layer for ZnO/PbS-CQD heterojunctions. With the insertion of this interlayer, the device performance is dramatically improved. The origins of this improvement are determined and it is found that the multifunctionality of the WPF-6-oxy-F interlayer offers the following essential benefits for the improved CQD/ZnO junctions: (i) the dipole induced by the ionic substituents enhances the quasi-Fermi level separation at the heterojunction through favorable energy band-bending, (ii) the ethylene oxide groups containing side chains can effectively passivate the interfacial defect sites of the heterojunction, and (iii) these effects occur without deterioration in the intrinsic depletion region or the series resistance of the device. All of the figures-of-merit of the devices are improved as a result of the enhanced built-in potential (electric field) and the reduced interfacial charge recombination at the heterojunction. The benefits due to the WPF-6-oxy-F interlayer are generally applicable to various types of PbS/ZnO heterojunctions. Finally, CQD photovoltaic devices with a power conversion efficiency of 9% are achievable, even by a solution process at room temperature in an air atmosphere. The work suggests a useful strategy to improve the interfacial properties of p-n heterojunctions by using polymeric interlayers. [ABSTRACT FROM AUTHOR]

A water-soluble cationic conjugated polyelectrolyte ( P1) containing fluorene, BODIPY and diacetylene moieties was synthesized and characterized. P1 showed two main absorption bands with maxima at 360 and 574 nm as well as fluorescence maxima at 648 nm due to the incorporation of BODIPY into the polymer backbone. Addition of CT DNA can quench the emission of P1 because of the formation of a P1/CT DNA complex, which was demonstrated by UV-vis spectra and dynamic light scattering (DLS) analyses. Cellular imaging results indicated P1 could be utilized as cellular imaging of HeLa cells, where red fluorescence was observed in the partial cytoplasm. Moreover, CCK-8 assay showed P1 had a low cytotoxicity. [ABSTRACT FROM AUTHOR]

Three types of cationic polyfluorenes with a different number of ionic groups are synthesized to modulate their solubility in water and the interactions with anionic oligonucleotide probes (DNA-C). Increasing the charge density improves the water-solubility of conjugated polyelectrolytes (CPEs) but decreases its optical antenna effect in the electrostatic sensory platform (CPE/DNA-C), resulting in low fluorescence resonance energy transfer (FRET) signal. With increasing charge density in CPE, the concentration of conjugated units in CPE/DNA-C decreases at [+]:[−] = 1:1, after which little driving force is expected to bring positive CPEs and negative DNA-C into close proximity for efficient FRET. CPF2 with 2 ionic groups (per repeat unit) and hydrophilic polyether side-chains exhibits good water-solubility and a higher FRET signal with an enhanced signal on/off ratio. In addition, the charge density in CPEs modulates the range of sensory responses by forming a tighter or weaker electrostatic CPE/DNA-C complex, which perturbs the probe-target binding interactions. [ABSTRACT FROM AUTHOR]

Three kinds of charged star‐shaped conjugated macroelectrolytes, named as PhNBr, TPANBr, and TrNBr, are synthesized as electron‐collecting interlayers for inverted polymer solar cells (i‐PSCs). Based on these well‐defined structured interlayer materials, the light soaking (LS) effect observed in i‐PSCs was studied systematically and accurately. The general character of the LS effect is further verified by studying additional i‐PSC devices functionalized with other common interlayers. The key‐role of UV photons was confirmed by electrochemical impedance spectroscopy and electron‐only devices. In addition, the ultraviolet photoelectron spectroscopy measurements indicate that the work function of the indium tin oxide (ITO)/interlayer cathode is significantly reduced after UV treatment. In these i‐PSC devices the LS effect originates from the adsorbed oxygen on the ITO substrates when oxygen plasma is used; however, even a small amount of oxygen from the ambient is also enough for triggering the LS effect, albeit with a weaker intensity. Our results suggest that the effect of adsorbed oxygen on ITO needs to be considered with attention while preparing i‐PSCs. This is an important finding that can aid the large‐scale manufacturing of organic solar cells via printing technologies, which do not always ensure the full protection of the device electrode substrates from oxygen. [ABSTRACT FROM AUTHOR]

Alkoxy side-chain tethered polyfluorene conjugated polyelectrolyte (CPE), poly[(9,9-bis((8-(3-methyl-1-imidazolium)octyl)-2,7-fluorene)-alt-(9,9-bis(2-(2-methoxyethoxy)ethyl)-fluorene)] dibromide (F8imFO4), is utilized to obtain CPE-hybridized ZnO nanoparticles (NPs) (CPE:ZnO hybrid NPs). The surface defects of ZnO NPs are passivated through coordination interactions with the oxygen atoms of alkoxy side-chains and the bromide anions of ionic pendent groups from F8imFO4 to the oxygen vacancies of ZnO NPs, and thereby the fluorescence quenching at the interface of yellow-emitting poly( p-phenylene vinylene)/CPE:ZnO hybrid NPs is significantly reduced at the CPE concentration of 4.5 wt%. Yellow-emitting polymer light-emitting diodes (PLEDs) with CPE(4.5 wt%):ZnO hybrid NPs as a cathode interfacial layer show the highest device efficiencies of 11.7 cd A−1 at 5.2 V and 8.6 lm W−1 at 3.8 V compared to the ZnO NP only (4.8 cd A−1 at 7 V and 2.2 lm W−1 at 6.6 V) or CPE only (7.3 cd A−1 at 5.2 V and 4.9 lm W−1 at 4.2 V) devices. The results suggest here that the CPE:ZnO hybrid NPs has a great potential to improve the device performance of organic electronics. [ABSTRACT FROM AUTHOR]

By coating conjugated polyelectrolytes (CPEs) on metals, the work function (WF) of metals can be tuned by electric dipoles formed through the selfassembly of cation-anion pairs on the side chains of CPEs. Recently, it has been reported that a pertinent oxidative doping of anionic CPEs results in a reversed direction in the net electric dipoles, thereby yielding opposite WF tunability compared with pristine CPEs. However, the fundamental mechanism of this reversed WF tunability is not clearly understood. Here, through a systematic study of the relationship between the chemical structure of anionic CPEs (n-type) and the corresponding oxidation-processed CPEs (p-type), it is clearly demonstrated that radical cations are generated on the π-conjugated backbone of the n-type CPEs and strongly paired with anions on the side chains of the n-type CPEs, thereby reversing the direction of the total net electric dipoles. Furthermore, it is found that the degree of radical cation-anion coupling in the CPEs is a key factor in determining their WF tunability. It is envisioned that the results will provide a fundamental understanding of CPEs for versatile interface engineering in organic electronics. [ABSTRACT FROM AUTHOR]

Water-soluble cationic alkynylplatinum(II) 2,6-bis(benzimidazol-2′-yl)pyridine (bzimpy) complexes have been demonstrated to undergo supramolecular assembly with anionic polyelectrolytes in aqueous buffer solution. Metal-metal-to-ligand charge transfer (MMLCT) absorptions and triplet MMLCT (3MMLCT) emissions have been found in UV/Vis absorption and emission spectra of the electrostatic assembly of the complexes with non-conjugated polyelectrolytes, driven by Pt⋅⋅⋅Pt and π-π interactions among the complex molecules. Interestingly, the two-component ensemble formed by [Pt(bzimpy-Et){CCC6H4(CH2NMe3-4)}]Cl2 ( 1) with para-linked conjugated polyelectrolyte (CPE), PPE-SO3−, shows significantly different photophysical properties from that of the ensemble formed by 1 with meta-linked CPE, mPPE-Ala. The helical conformation of mPPE-Ala allows the formation of strong mPPE-Ala- 1 aggregates with Pt⋅⋅⋅Pt, electrostatic, and π-π interactions, as revealed by the large Stern-Volmer constant at low concentrations of 1. Together with the reasonably large Förster radius, large HOMO-LUMO gap and high triplet state energy of mPPE-Ala to minimize both photo-induced charge transfer (PCT) and Dexter triplet energy back-transfer (TEBT) quenching of the emission of 1, efficient Förster resonance energy transfer (FRET) from mPPE-Ala to aggregated 1 molecules and strong 3MMLCT emission have been found, while the less strong PPE-SO3−- 1 aggregates and probably more efficient PCT and Dexter TEBT quenching would account for the lack of 3MMLCT emission in the PPE-SO3−- 1 ensemble. [ABSTRACT FROM AUTHOR]

ABSTRACT Two novel ID-based water-soluble conjugated polymers (+)-PIDPV and (−)-PIDPV were synthesized by Heck coupling reaction. These two polyelectrolytes are both consisted of isoindigo units and phenylenevinylene units. In the UV-vis absorption spectra, both (+)-PIDPV and (−)-PIDPV exhibit broad absorption bands that almost cover the whole visible region. Photophysical investigations reveal that the fluorescence of water-soluble PPV can be efficiently quenched by oppositely charged PIDPV at a very low concentration. Cationic PPV shows an efficient quenching effect with ΚSV = 1.01 × 106 M−1 in the presence of (−)-PIDPV while the anionic PPV gives a lager quenching constant with ΚSV = 1.71 × 106 M−1 in the presence of (+)-PIDPV. Furthermore, the blend films of water-soluble PPVs and oppositely charged PIDPV also exhibit excellent quenching effect. These properties suggest that (+)-PIDPV and (−)-PIDPV are promising materials in the application of ionic photoactive layer in the organic solar cells. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2223-2237 [ABSTRACT FROM AUTHOR]

p‐Type conjugated polyelectrolytes (CPEs) are developed as organic‐based work‐function‐modifier materials for the broad work‐function (WF) tunability of various metal electrodes. Facile oxidative treatments of n‐type CPEs using various oxidants produce unprecedented p‐type CPEs with reversed electronic properties corresponding to n‐type CPEs, resulting in fine WF tuning of adjacent metal electrodes. This change leads to substantial increases in power conversion efficiency and lifetime of organic solar cells. [ABSTRACT FROM AUTHOR]

This article summarizes the recent advances of benzothiadiazole (BT)-containing conjugated polyelectrolytes (CPEs) for biological sensing and imaging. After a brief introduction of the molecular design principles, the application of linear BT-containing CPEs as multicolor or light-up probes for visual sensing of biomolecules is reviewed. Then, linear, grafted, and hyperbranched BT-containing CPEs that can self-assemble into nanoparticles or have intrinsic 3D structures for in vitro and in vivo imaging are summarized. The future outlook of BT-containing CPEs for biomedical applications is also discussed at the end. [ABSTRACT FROM AUTHOR]

Conjugated polyelectrolytes (CPEs) have gain great research interest during the past decades. The incorporation of phosphorescent transition-metal complexes into CPEs backbones could yield organometallic CPEs (OMCPEs), which exhibit unique physical and chemical properties, enabling their applications in electroluminescence device, sensing, bioimaging and photodynamic therapy fields. This review begins with a brief introduction of synthetic approaches towards OMCPEs, followed by summary of the recent advances for applications. Some outlooks are also highlighted at the end. [ABSTRACT FROM AUTHOR]