Near-Infrared Emissive Super Penetrating Conjugated Polymer Dots for Intratumoral Imaging in 3D Tumor Spheroid Models.

This study describes the formation of single-chain polymer dots (Pdots) via ultrasonic emulsification of nonionic donor-acceptor-donor type (D-A-D) alkoxy thiophene-benzobisthiadiazole-based conjugated polymers (Poly BT) with amphiphilic cetyltrimethylammonium bromide (CTAB). The methodology yields Pdots with a high cationic surface charge (+56.5 mV ± 9.

Fabrication of gelatin-polyester based biocomposite scaffold via one-step functionalization of melt electrowritten polymer blends in aqueous phase.

The rapid manufacturing of biocomposite scaffold made of saturated-Poly(ε-caprolactone) (PCL) and unsaturated Polyester (PE) blends with gelatin and modified gelatin (NCO-Gel) is demonstrated. Polyester blend-based scaffold are fabricated with and without applying potential in the melt electrowriting system. Notably, the applied potential induces phase separation between PCL and PE and drives the formation of PE rich spots at the interface of electrowritten fibers.

Heavy metals contamination and ecological risks in agricultural soils of Uşak, western Türkiye: a geostatistical and multivariate analysis.

This research aimed to determine and evaluate the concentrations of As, Cu, Hg, Ni, and Pb, and the physicochemical properties of 48 agricultural soil samples, to identify potential ecological risks and their sources associated with heavy metals contamination in Usak, western Türkiye. Various methods were used to assess ecological risks, including geoaccumulation index (I), enrichment factor (EF), degree of contamination (C), potential ecological risk (RI), and pollution load index (PLI). The heavy metals concentrations ranged from 4 to 61 mg/kg for As, 8-48 mg/kg for Cu, 0.

The Soft Nanodots as Fluorescent Probes for Cell Imaging: Analysis of Cell and Spheroid Penetration Behavior of Single Chain Polymer Dots.

This study describes the formation, size control, and penetration behavior of polymer nanodots (Pdots) consisting of single or few chain polythiophene-based conjugated polyelectrolytes (CPEs) via nanophase separation between good solvent and poor solvent of CPE. Though the chain singularity may be associated with dilution nanophase separation suggests that molecules of a good solvent create a thermodynamically driven solvation layer surrounding the CPEs and thereby separating the single chains even in their poor solvents. This statement is therefore corroborated with emission intensity/lifetime, particle size, and scattering intensity of polyelectrolyte in good and poor solvents.

Thickness Gradient in Polymer Coating by Reactive Layer-by-Layer Assembly on Solid Substrate.

The study describes a simple yet robust methodology for forming gradients in polymer coatings with nanometer-thickness precision. The thickness gradients of 0-20 nm in the coating are obtained by a reactive layer-by-layer assembly of polyester and polyethylenimine on gold substrates. Three parameters are important in forming thickness gradients: (i) the incubation time, (ii) the incubation concentration of the polymer solutions, and (iii) the tilt angle of the gold substrate during the dipping process.

Colorimetric Assaying of Exosomal Metabolic Biomarkers.

Exosomes released into the extracellular matrix have been reported to contain metabolic biomarkers of various diseases. These intraluminal vesicles are typically found in blood, urine, saliva, breast milk, cerebrospinal fluid, semen, amniotic fluid, and ascites. Analysis of exosomal content with specific profiles of DNA, microRNA, proteins, and lipids can mirror their cellular origin and physiological state.

Greenness of lab-on-a-chip devices for analytical processes: Advances & future prospects.

Lab-on-a-chip devices have now-a-days become an important aspect of analytical/bioanalytical chemistry having wide range of applications including clinical diagnosis, drug screening, cell biology, environmental monitoring, food safety analysis etc. Conventional lab-on-a-chip devices generally employ chemicals that are not environmentally friendly and were commonly fabricated on hard plastic platform which are non-degradable and hence ignore the importance of green analytical chemistry. In today's scenario, it is highly imperative to protect our environment by using less toxic and environmentally friendly chemicals/solvents and biocompatible platforms.

A Perspective on Polythiophenes as Conformation Dependent Optical Reporters for Label-Free Bioanalytics.

Poly(3-alkylthiophene) (PT)-based conjugated polyelectrolytes (CPEs) constitute an important class of responsive polymers with excellent optical properties. The electrostatic interactions between PTs and target analytes trigger complexation and concomitant conformational changes of the PT backbones that produce distinct optical responses. These conformation-induced optical responses of the PTs enable them to be utilized as reporters for detection of various analytes by employing simple UV-vis spectrophotometry or the naked eye.

Gadolinium and Polythiophene Functionalized Polyurea Polymer Dots as Fluoro-Magnetic Nanoprobes.

A rapid and one-pot synthesis of poly 3-thiopheneacetic acid (PTAA) functionalized polyurea polymer dots (Pdots) using polyethyleneimine and isophorone diisocyanate is reported. The one-pot mini-emulsion polymerization technique yielded Pdots with an average diameter of ~20 nm. The size, shape, and concentration of the surface functional groups could be controlled by altering the synthesis parameters such as ultrasonication time, concentration of the surfactant, and crosslinking agent, and the types of isocyanates utilized for the synthesis.

Colorimetric and Fluorometric Profiling of Advanced Glycation End Products.

Profiling of advanced glycation end products (AGEs) is an emerging area of clinical significance for disease diagnosis and prognosis. Typically, concentrations of AGEs are estimated in laboratories by trained personnel using sophisticated equipment. Herein, a facile approach for colorimetric and fluorometric profiling of AGEs is reported for rapid and on-site analysis.

Electroactive Nanogel Formation by Reactive Layer-by-Layer Assembly of Polyester and Branched Polyethylenimine via Aza-Michael Addition.

We here demonstrate the utilization of reactive layer-by-layer (rLBL) assembly to form a nanogel coating made of branched polyethylenimine (BPEI) and alkyne containing polyester (PE) on a gold surface. The rLBL is generated by the rapid aza-Michael addition reaction of the alkyne group of PE and the -NH groups of BPEI by yielding a homogeneous gel coating on the gold substrate. The thickness profile of the nanogel revealed that a 400 nm thick coating is formed by six multilayers of rLBL, and it exhibits 50 nm roughness over 8 μm distance.

Glucuronoxylan-based quince seed hydrogel: A promising scaffold for tissue engineering applications.

Natural gums and mucilages from plant-derived polysaccharides are potential candidates for a tissue-engineering scaffold by their ability of gelation and biocompatibility. Herein, we utilized Glucuronoxylan-based quince seed hydrogel (QSH) as a scaffold for tissue engineering applications. Optimization of QSH gelation was conducted by varying QSH and crosslinker glutaraldehyde (GTA) concentrations.

PCR-Free Methodology for Detection of Single-Nucleotide Polymorphism with a Cationic Polythiophene Reporter.

This study presents a nonamplification-based nucleic acid assay for the detection of single-nucleotide polymorphism (SNP) associated with familial Mediterranean fever (FMF) besides polymerase chain reaction (PCR)-based methodologies. The major objective is to show the potential of the proposed assay for rapid screening of FMF in a Mediterranean region of 400 million population. The assay relies on binding difference of specially designed wild and mutant primers to the target genomic DNA, followed by determination of unbound primers by quick titration of a cationic polythiophene reporter.

Colorimetric Urinalysis for On-Site Detection of Metabolic Biomarkers.

Over the past few decades, colorimetric assays have been developed for cost-effective and rapid on-site urinalysis. Most of these assays were employed for detection of biomarkers such as glucose, uric acid, ions, and albumin that are abundant in urine at micromolar to millimolar levels. In contrast, direct assaying of urinary biomarkers such as glycated proteins, low-molecular-weight reactive oxygen species, and nucleic acids that are present at significantly lower levels (nanomolar to picomolar) remain challenging due to the interferences from the urine sample matrix.

Fabrication of a Postfunctionalizable, Biorepellent, Electroactive Polyurethane Interface on a Gold Surface by Surface-Assisted Polymerization.

This study describes surface-assisted (SurfAst) urethane polymerization, providing a modular/postfunctionalizable, biorepellent, electroactive ∼10 to 100 nm-thick polyurethane (PU) interface on a gold surface. SurfAst is a functionalization methodology based on sequential incubation steps of alkane diisocyanates and alkanediol monomers. The gold surface is functionalized by alkane diisocyanates in the first incubation step, and our theoretical calculations reveal that while the isocyanate group atoms (N, C, and O) at one end of the molecule exhibits strong interactions (∼900 meV) with surface atoms, the other end group remains unreacted.

Pixelated colorimetric nucleic acid assay.

Conjugated polyelectrolytes (CPEs) have been widely used as reporters in colorimetric assays targeting nucleic acids. CPEs provide naked eye detection possibility by their superior optical properties however, as concentration of target analytes decrease, trace amounts of nucleic acid typically yield colorimetric responses that are not readily perceivable by naked eye. Herein, we report a pixelated analysis approach for correlating colorimetric responses of CPE with nucleic acid concentrations down to 1 nM, in plasma samples, utilizing a smart phone with an algorithm that can perform analytical testing and data processing.

Biomimetic hybrid scaffold consisting of co-electrospun collagen and PLLCL for 3D cell culture.

Electrospun collagen is commonly used as a scaffold in tissue engineering applications since it mimics the content and morphology of native extracellular matrix (ECM) well. This report describes "toxic solvent free" fabrication of electrospun hybrid scaffold consisting of Collagen (Col) and Poly(l-lactide-co-ε-caprolactone) (PLLCL) for three-dimensional (3D) cell culture. Biomimetic hybrid scaffold was fabricated via co-spinning approach where simultaneous electrospinning of PLLCL and Collagen was mediated by polymer sacrificing agent Polyvinylpyrrolidone (PVP).

Single Chain Cationic Polymer Dot as a Fluorescent Probe for Cell Imaging and Selective Determination of Hepatocellular Carcinoma Cells.

This letter describes formation of single chain cationic polymer dots (Pdots) made of poly[1,4-dimethyl-1-(3-((2,4,5-trimethylthiophen-3-yl)oxy)propyl)piperazin-1-ium bromide] conjugated polyelectrolyte (CPE). The single chain Pdot formation relies on a simple process which is a rapid nanophase separation between CPE solution of ethylene glycol and water. Pdots show narrow monodisperse size distribution with a 3.

Flow-through colorimetric assay for detection of nucleic acids in plasma.

A flow-through colorimetric assay for detection of nucleic acids in plasma is reported. The proposed assay features an array of four polyvinylidene fluoride (PVDF) membranes impregnated with cationic poly (3-alkoxy-4-methylthiophene) (PT) as an optical reporter. The sensing strategy is based on monitoring the changes in optical properties of PT, upon complexation with target nucleic acids in the presence and in the absence of their corresponding complementary peptide nucleic acids (PNAs).

Hand-Held Volatilome Analyzer Based on Elastically Deformable Nanofibers.

This study reports on a hand-held volatilome analyzer for selective determination of clinically relevant biomarkers in exhaled breath. The sensing platform is based on electrospun polymer nanofiber-multiwalled carbon nanotube (MWCNT) sensing microchannels. Polymer nanofibers of poly(vinylidene fluoride) (PVDF), polystyrene (PS), and poly(methyl methacrylate) (PMMA) incorporated with MWCNT exhibits a stable response to interferences of humidity and CO and provides selective deformations upon exposure of exhaled breath target volatilomes acetone and toluene, exhibiting correlation to diabetes and lung cancer, respectively.

Luminescent Device for the Detection of Oxidative Stress Biomarkers in Artificial Urine.

A luminescent paper-based device for the visual detection of oxidative stress biomarkers is reported. The device consists of a polyvinylidene fluoride membrane impregnated with poly(3-alkoxy-4-methylthiophene) (PT) for colorimetric detection. 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker associated with oxidative stress, is used as a model system for validating the proposed methodology.

A BODIPY-Based Fluorescent Probe to Visually Detect Phosgene: Toward the Development of a Handheld Phosgene Detector.

A boron-dipyrromethene (BODIPY)-based fluorescent probe with a phosgene-specific reactive motif shows remarkable selectivity toward phosgene, in the presence of which the nonfluorescent dye rapidly transforms into a new structure and induces a fluorescent response clearly observable to the naked eye under ultraviolet light. Given that dynamic, a prototypical handheld phosgene detector with a promising sensing capability that expedites the detection of gaseous phosgene without sophisticated instrumentation was developed. The proposed method using the handheld detector involves a rapid response period suitable for issuing early warnings during emergency situations.

Tailoring Conformation-Induced Chromism of Polythiophene Copolymers for Nucleic Acid Assay at Resource Limited Settings.

Here we report on the design and synthesis of cationic water-soluble thiophene copolymers as reporters for colorimetric detection of microRNA (miRNA) in human plasma. Poly(3-alkoxythiophene) (PT) polyelectrolytes with controlled ratios of pendant groups such as triethylamine/1-methyl imidazole were synthesized for optimizing interaction with target miRNA sequence (Tseq). Incorporation of specific peptide nucleic acid (PNA) sequences with the cationic polythiophenes yielded distinguishable responses upon formation of fluorescent PT-PNA-Tseq triplex and weakly fluorescent PT-Tseq duplex, thereby enabling selective detection of target miRNA.

Visual detection of Al(3+) ions using conjugated copolymer-ATP supramolecular complex.

A colorimetric Al(3+) sensor based on fluorescence recovery of a conjugated copolymer-ATP complex is proposed. An optimized ratio of two polythiophene (PT) monomers is utilized to synthesize copolymer (CP) that yielded maximized colorimetric response for Al(3+) in deionized (DI) and tap water. The electrostatic disassembly of CP-ATP upon addition of Al(3+) led to an evident visual color change.