Easy-to-Engineer Flexible Nanoelectrode Sensor from an Inexpensive Overhead Projector Sheet for Sweat Neuropeptide-Y Detection.

In this paper, we report an inexpensive and easy-to-engineer flexible nanobiosensor electrode platform by exploring a nonconductive overhead projector (OHP) sheet for sweat Neuropeptide-Y (NPY) detection, a potential biomarker for stress, cardiovascular regulation, appetite, etc. We converted a nonconductive OHP sheet into a conductive nanobiosensor electrode platform with a hybrid polymerization method, which consists of interfacial polymerization of pyrrole and a template-free electropolymerization technique to decorate the electrode platform with poly(EDOT-COOH--EDOT-EG3) nanotubes. The selection of poly(EDOT-COOH) features an easy conjugation of NPY antibody (NPY-Ab) through EDC/Sulfo-NHS coupling chemistry, while poly(EDOT-EG3) is best known to reduce nonspecific binding of biomolecules.

Recent advances in PEDOT/PProDOT-derived nano biosensors: engineering nano assemblies for fostering advanced detection platforms for biomolecule detection.

With the recent unprecedented emergence of a global pandemic, unknown diseases and new metabolic patterns expressing serious health issues, the requirement to develop new diagnostic tools, therapeutic solutions, and healthcare and environmental monitoring systems are significantly higher in the present situation. Considering that high sensitivity, selectivity, stability and a low limit of detection (LOD) are inevitable requirements for an ideal biosensor, the class of conducting polymers of poly(3,4-ethylenedioxythiophene) (PEDOT) and recently poly(3,4-propylenedioxythiophene) (PProDOT) materials have been demonstrated to be promising candidates for designing sensor devices. Nanostructure engineering of these polymeric materials with tunable surface properties and side chain functionalization to enable sensor probe conjugation combined with signal amplification devices such as OECTs and OFETs can fulfil the requirements of next-generation smart nano-biosensors.

Gradient conducting polymer surfaces with netrin-1-conjugation promote axon guidance and neuron transmission of human iPSC-derived retinal ganglion cells.

Major advances have been made in utilizing human-induced pluripotent stem cells (hiPSCs) for regenerative medicine. Nevertheless, the delivery and integration of hiPSCs into target tissues remain significant challenges, particularly in the context of retinal ganglion cell (RGC) restoration. In this study, we introduce a promising avenue for providing directional guidance to regenerated cells in the retina.

Detection of SARS-CoV-2 Spike Protein Using Micropatterned 3D Poly(3,4-Ethylenedioxythiophene) Nanorods Decorated with Gold Nanoparticles.

The sensitivity and fabrication process of the detection platform are important for developing viral disease diagnosis. Recently, the outbreak of SARS-CoV-2 compelled us to develop a new detection platform to control such diseases in the future. We present an electrochemical-based assay that employs the unique properties of gold nanoparticles (AuNPs) deposited on 3D carboxyl-functionalized poly(3,4-ethylenedioxythiophene) (PEDOTAc) nanorods for specific and sensitive detection of SARS-CoV-2 spike protein (S1).

Nano-On-Nano: Responsive Nanosubstrate-Mediated Liposome Delivery with High Cellular Uptake Efficiency.

Efficiently delivering liposomal content to cells in a relatively uniform dose and patterned fashion, especially bypassing the degradative endocytosis pathway, is an important technology in cell culture and potentially to tissue engineering that still remains challenging. We developed a "nano-on-nano" platform technology that consists of the following three material features: (1) high density silicon nanopillars to create a pseudo-3-dimensional nanoenvironment for cell culturing, (2) thermoresponsive polymer grafted onto silicon nanopillars to form a responsive nanosubstrate, and (3) immobilized liposomes using a biotin-streptavidin-biotin conjugation. The working principle is that the liposomes are detached for cellular uptake upon thermal stimulation and high local liposome concentration between the cells and substrates drives the cellular uptake with nonendocytic pathways.

Smart Thermoresponsive Electrospun Nanofibers with On-Demand Release of Carbon Quantum Dots for Cellular Uptake.

Developing a smart responsive surface for on-demand delivery of organic, inorganic, and biological cargo in vitro cellular uptake is always in constant demand. Herein, we present carbon quantum dot (CQD)-loaded (poly(-isopropylacrylamide) (PNIPAAm)/poly(methyl methacrylate (PMMA)) blend nanofiber sheets having a thermoresponsive nature. As a model cargo, fluorescent CQDs are used for the demonstration of the on-demand delivery mechanism.

Biguanide- and Oligo(Ethylene Glycol)-Functionalized Poly(3,4-Ethylenedioxythiophene): Electroactive, Antimicrobial, and Antifouling Surface Coatings.

The challenge of infectious diseases remains a critical concern to the global public health. Recently, it is common to encounter touch-screen electronic devices everywhere to access services. The surface of such devices may easily get contaminated by an infected person, which leads to transmission of infectious diseases between individuals.

Sensitive Detection of Sweat Cortisol Using an Organic Electrochemical Transistor Featuring Nanostructured Poly(3,4-Ethylenedioxythiophene) Derivatives in the Channel Layer.

In this study, we examined the influence of functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) nanostructures decorated on the channel layer of an organic electrochemical transistor (OECT) for the detection of sweat cortisol, an adrenocorticosteroid stress hormone. The OECT device featured a bilayer channel confined by a PEDOT:polystyrenesulfonate (PSS) underlayer and a nanostructure-decorated upper layer engineered from the monomers EDOT-COOH and EDOT-EG3 through template-free electrochemical polymerization. This molecular design allowed antibody conjugation using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/-hydroxysulfosuccinimide coupling through the carboxylic acid side chain, with EDOT-EG3 known to minimize nonspecific binding of biomolecules.

Hybrid "Kill and Release" Antibacterial Cellulose Papers Obtained via Surface-Initiated Atom Transfer Radical Polymerization.

Infectious diseases triggered by bacteria cause a severe risk to human health. To counter this issue, surfaces coated with antibacterial materials have been widely used in daily life to kill these bacteria. The substrates enabled with a hybrid kill and release strategy can be employed not only to kill the bacteria but also to wash them using external stimuli (temperature, pH, etc.

Molecular and nano structures of chiral PEDOT derivatives influence the enantiorecognition of biomolecules. analysis of chiral recognition.

In this study we investigated the synergistic effects of the chirality (molecular structure) and surface morphology (nanostructure) of a newly designed sensing platform for the stereoselective recognition of biomolecules. We synthesized 3,4-ethylenedioxythiophene monomers presenting an OH functional group on the side chain (EDOT-OH) with either or chirality and then electropolymerized them in a template-free manner to engineer poly(EDOT-OH) nanotubes and smooth films with or chirality. We used a quartz crystal microbalance (QCM) to examine the differential binding of fetal bovine serum, RGD peptide, insulin, and ()- and ()-mandelic acid (MA) on these chiral polymeric platforms.

Self-Cleaning Cotton Obtained after Grafting Thermoresponsive Poly(-vinylcaprolactam) through Surface-Initiated Atom Transfer Radical Polymerization.

Although the performance of smart textiles would be enhanced if they could display self-cleaning ability toward various kinds of contamination, the procedures that have been used previously to impart the self-cleaning potential to these functional fabrics (solvent casting, dip coating, spin coating, surface crosslinking) have typically been expensive and/or limited by uncontrollable polymer thicknesses and morphologies. In this paper, we demonstrate the use of atomic transfer radical polymerization for the surface-initiated grafting of poly(-vinylcaprolactam), a thermoresponsive polymer, onto cotton. We confirmed the thermoresponsiveness and reusability of the resulting fabric through water contact angle measurements and various surface characterization techniques (scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy).

Purification of HCC-specific extracellular vesicles on nanosubstrates for early HCC detection by digital scoring.

We report a covalent chemistry-based hepatocellular carcinoma (HCC)-specific extracellular vesicle (EV) purification system for early detection of HCC by performing digital scoring on the purified EVs. Earlier detection of HCC creates more opportunities for curative therapeutic interventions. EVs are present in circulation at relatively early stages of disease, providing potential opportunities for HCC early detection.

Synthesis of MOF525/PEDOT Composites as Microelectrodes for Electrochemical Sensing of Dopamine.

Dopamine (DA) is an important neurotransmitter responsible for the functions and activities of multiple systems in human. Electrochemical detection of DA has the advantages of fast analysis and cost-effectiveness, while a regular electrode probe is restricted to laboratory use because the probe size is too large to be suitable for an in vivo or in vitro analysis. In this study, we have developed porphyrin-based metal organic framework (MOF525) and poly(3,4-ethylenedioxythiophene) (PEDOT)-based composites to modify microelectrode for DA detection.

Mechanotactic Activation of TGF-β by PEDOT Artificial Microenvironments Triggers Epithelial to Mesenchymal Transition.

Epithelial to mesenchymal transition (EMT) is integral for cells to acquire metastatic properties, and ample evidence links it to bioorganic framework of the tumor microenvironment (TME). Hydroxymethyl-functionalized 3,4-ethylenedioxythiophene polymer (PEDOT-OH) enables construction of diverse nanotopography size and morphologies and is therefore exploited to engineer organic artificial microenvironments bearing nanodots from 300 to 1000 nm in diameter to understand spatiotemporal EMT regulation by biophysical components of the TME. MCF-7 breast cancer cells are cultured on these artificial microenvironments, and temporal regulation of cellular morphology and EMT markers is investigated.

Tunable Protein/Cell Binding and Interaction with Neurite Outgrowth of Low-Impedance Zwitterionic PEDOTs.

Zwitterionic poly(3,4-ethylenedioxythiophene) (PEDOT) is an effective electronic material for bioelectronics because it exhibits efficient electrical trade-off and diminishes immune response. To promote the use of zwitterionic PEDOTs in bioelectronic devices, especially for cell alignment control and close electrocoupling, features such as tunable interaction of PEDOTs with proteins/cells and spatially modulating cell behavior are required. However, there is a lack of reliable methods to assemble zwitterionic EDOTs with other functionalized EDOT materials, having different polarities and oxidation potentials, to prepare PEDOTs with the aforementioned surface properties.

Ultrastable tetraphenyl-p-phenylenediamine-based covalent organic frameworks as platforms for high-performance electrochemical supercapacitors.

In this study we synthesized two tetraphenyl-p-phenylenediamine-based covalent organic frameworks (TPPDA-TPPyr and TPPDA-TPTPE COFs) for potential use in high-performance electrochemical supercapacitors. This excellent performance arose from their structures containing redox-active triphenylamine derivatives and their high surface areas.

Covalent chemistry on nanostructured substrates enables noninvasive quantification of gene rearrangements in circulating tumor cells.

Well-preserved mRNA in circulating tumor cells (CTCs) offers an ideal material for conducting molecular profiling of tumors, thereby providing a noninvasive diagnostic solution for guiding treatment intervention and monitoring disease progression. However, it is technically challenging to purify CTCs while retaining high-quality mRNA.Here, we demonstrate a covalent chemistry-based nanostructured silicon substrate ("Click Chip") for CTC purification that leverages bioorthogonal ligation-mediated CTC capture and disulfide cleavage-driven CTC release.

Organic Electrochemical Transistors/SERS-Active Hybrid Biosensors Featuring Gold Nanoparticles Immobilized on Thiol-Functionalized PEDOT Films.

In this study we immobilized gold nanoparticles (AuNPs) onto thiol-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) films as bioelectronic interfaces (BEIs) to be integrated into organic electrochemical transistors (OECTs) for effective detection of dopamine (DA) and also as surface-enhanced Raman scattering (SERS)-active substrates for the selective detection of -cresol (PC) in the presence of multiple interferers. This novel PEDOT-based BEI device platform combined (i) an underlying layer of polystyrenesulfonate-doped PEDOT (PEDOT:PSS), which greatly enhanced the transconductance and sensitivity of OECTs for electrochemical sensing of DA in the presence of other ascorbic acid and uric acid metabolites, as well as amperometric response toward DA with a detection limit (S/N = 3) of 37 nM in the linear range from 50 nM to 100 μM; with (ii) a top interfacial layer of AuNP-immobilized three-dimensional (3D) thiol-functionalized PEDOT, which not only improved the performance of OECTs for detecting DA, due to the signal amplification effect of the AuNPs with high catalytic activity, but also enabled downstream analysis (SERS detection) of PC on the same chip. We demonstrate that PEDOT-based 3D OECT devices decorated with a high-density of AuNPs can display new versatility for the design of next-generation biosensors for point-of-care diagnostics.

Deprotonation-Induced Conductivity Shift of Polyethylenedioxythiophenes in Aqueous Solutions: The Effects of Side-Chain Length and Polymer Composition.

Deprotonation-induced conductivity shift of poly(3,4-ethylenedixoythiophene)s (PEDOTs) in aqueous solutions is a promising platform for chemical or biological sensor due to its large signal output and minimum effect from material morphology. Carboxylic acid group functionalized poly(C-EDOT-COOH)s are synthesized and electrodeposited on microelectrodes. The microelectrodes are utilized to study the effect of carboxylic acid side-chain length on the conductivity curve profiles in aqueous buffer with different pH.

A Hollow Microtubular Triazine- and Benzobisoxazole-Based Covalent Organic Framework Presenting Sponge-Like Shells That Functions as a High-Performance Supercapacitor.

In this paper we report the construction of a hollow microtubular triazine- and benzobisoxazole-based covalent organic framework (COF) presenting a sponge-like shell through a template-free [3+2] condensation of the planar molecules 2,4,6-tris(4-formylphenyl)triazine (TPT-3CHO) and 2,5-diaminohydroquinone dihydrochloride (DAHQ-2HCl). The synthesized COF exhibited extremely high crystallinity, a high surface area (ca. 1855 m  g ), and ultrahigh thermal stability.

Electrically Responsive, Nanopatterned Surfaces for Triggered Delivery of Biologically Active Molecules into Cells.

Polyelectrolyte multilayers (PEMs) assembled layer-by-layer have emerged as functional polymer films that are both stable and capable of containing drug molecules for controlled release applications. Most of these applications concentrate on sustained release, where the concentration of the released molecules remains rather constant with time. However, high-efficiency delivery requires obtaining high local concentrations at the vicinity of the cells, which is achieved by triggered release.

Correction: In vitro selection of electrochemical peptide probes using bioorthogonal tRNA for influenza virus detection.

Correction for 'In vitro selection of electrochemical peptide probes using bioorthogonal tRNA for influenza virus detection' by Tara Bahadur K. C. et al.

In vitro selection of electrochemical peptide probes using bioorthogonal tRNA for influenza virus detection.

An electrosensitive peptide probe has been developed from an in vitro selection technique using biorthogonal tRNA prepared with an electroreactive non-natural amino acid, 3,4-ethylenedioxythiophene-conjugated aminophenylalanine. The selected probe quantitatively detected the influenza virus based on a signal "turn-on" mechanism. The developed strategy could be used to develop electrochemical biosensors toward a variety of targets.