Recent advances in the aqueous applications of PEDOT

Electroactive Polymers for On-Demand Drug Release

Conductive materials have played a significant role in advancing society into the digital era. Such materials are able to harness the power of electricity and are used to control many aspects of daily life. Conductive polymers (CPs) are an emerging group of polymers that possess metal-like conductivity yet retain desirable polymeric features, such as processability, mechanical properties, and biodegradability. Upon receiving an electrical stimulus, CPs can be tailored to achieve a number of responses, such as harvesting energy and stimulating tissue growth. The recent FDA approval of a CP-based material for a medical device has invigorated their research in healthcare. In drug delivery, CPs can act as electrical switches, drug release is achieved at a flick of a switch, thereby providing unprecedented control over drug release. In this review, recent developments in CP as electroactive polymers for voltage-stimuli responsive drug delivery systems are evaluated. The review demonstrates the distinct drug release profiles achieved by electroactive formulations, and both the precision and ease of stimuli response. This level of dynamism promises to yield "smart medicines" and warrants further research. The review concludes by providing an outlook on electroactive formulations in drug delivery and highlighting their integral roles in healthcare IoT.

Dopamine induced multiple bonding in hyaluronic acid network to construct particle-free conductive hydrogel for reliable electro-biosensing

Conductive hydrogel (CH) as flexible electrophysiology interface has become the new trend of bioelectronics, but still challenging in synergizing the biocompatibility, mechanics and comprehensive electrical performance. Hyaluronic acid (HA), featured with abundant active sites for personalized-modification and well-known biocompatibility, is one of the alterative candidates. The obstacle lies in the unstable conductivity from the ionic conduction, and the electronic conduction by embedding conductive nanoparticles (NPs) is likely to result in inhomogeneous CH with poor stretchability and discontinuous conductive network. Herein, inspired by catechol chemistry, dopamine (DA)-modified HA was homogeneously composited with DA-modified poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS, named PP), to produce particle-free conductive hydrogel (HA-DA-PP). The DA-introduced multiple bondings in HA network and PP molecules brought aqueous conductive PP into HA hydrogel to form a homogeneous crosslinking network, imparted the flexible stretchability. By accurately regulation, HA-DA-PP achieved high stretchability with large tensile deformation (over 470 %) in the category of natural polymer-based hydrogels. Moreover, the interaction between DA and PP (conformational transition and charge transfer) could effectively enhance the hydrogel's conductivity. Consequently, HA-DA-PP hydrogel showed high sensibility to human movement, epidermal and in vivo electrophysiological signals monitoring. Overall, DA-mediated multiple bonding is a powerful strategy for constructing CH with high performance for bioelectronics.

Towards Highly Efficient Cesium Titanium Halide Based Lead-Free Double Perovskites Solar Cell by Optimizing the Interface Layers

Lead halide perovskites are the most promising compared to the other recently discovered photovoltaic materials, but despite their enormous potential, these materials are facing some serious concerns regarding lead-based toxicity. Among many lead-free perovskites, the vacancy-ordered double perovskite cesium titanium halide family (Cs₂TiX₆, X = Cl, Br, I) is very popular and heavily investigated and reported on. The main objective of this study is to design and compare an efficient cesium titanium halide-based solar cell that can be used as an alternative to lead-based perovskite solar cells. For efficient photovoltaic requirements, the hole-transport layer and electron-transport layer materials such as PEDOT:PSS and Nb₂O₅ are selected, as these are the commonly reported materials and electronically compatible with the cesium titanium halide family. For the active layer, cesium titanium halide family members such as Cs₂TiCl₆, Cs₂TiBr₆, and Cs₂TiI₆ are reported here for the devices ITO/Nb₂O₅/Cs₂TiI₆/PEDOT:PSS/Au, ITO/Nb₂O₅/Cs₂TiBr₆/PEDOT:PSS/Au, and ITO/Nb₂O₅/Cs₂TiCl₆/PEDOT:PSS/Au, respectively. To determine the most efficient photovoltaic response, all the layers (PEDOT:PSS, Nb₂O₅, and active perovskite layer) of each device are optimized concerning thickness as well as doping density, and then each optimized device was systematically investigated for its photovoltaic responses through simulation and modeling. It is observed that the device ITO/Nb₂O₅/Cs₂TiI₆/PEDOT:PS/Au shows the most efficient photovoltaic response with little above 18.5% for maximum power-conversion efficiency.

PEDOT-Carbon Nanotube Counter Electrodes and Bipyridine Cobalt (II/III) Mediators as Universally Compatible Components in Bio-Sensitized Solar Cells Using Photosystem I and Bacteriorhodopsin

In nature, solar energy is captured by different types of light harvesting protein–pigment complexes. Two of these photoactivatable proteins are bacteriorhodopsin (bR), which utilizes a retinal moiety to function as a proton pump, and photosystem I (PSI), which uses a chlorophyll antenna to catalyze unidirectional electron transfer. Both PSI and bR are well characterized biochemically and have been integrated into solar photovoltaic (PV) devices built from sustainable materials. Both PSI and bR are some of the best performing photosensitizers in the bio-sensitized PV field, yet relatively little attention has been devoted to the development of more sustainable, biocompatible alternative counter electrodes and electrolytes for bio-sensitized solar cells. Careful selection of the electrolyte and counter electrode components is critical to designing bio-sensitized solar cells with more sustainable materials and improved device performance. This work explores the use of poly (3,4-ethylenedioxythiophene) (PEDOT) modified with multi-walled carbon nanotubes (PEDOT/CNT) as counter electrodes and aqueous-soluble bipyridine cobalt^II/III complexes as direct redox mediators for both PSI and bR devices. We report a unique counter electrode and redox mediator system that can perform remarkably well for both bio-photosensitizers that have independently evolved over millions of years. The compatibility of disparate proteins with common mediators and counter electrodes may further the improvement of bio-sensitized PV design in a way that is more universally biocompatible for device outputs and longevity.