This study explores the potential of reaction-based optical fingerprinting and total X-ray fluorescence (TXRF) elemental analysis, both separately and in combination, as a rapid and inexpensive approach to preliminary cancer diagnostics. Plasma samples from BALB/c mice with transplanted mammary carcinoma (EMT-6) and BDF1 mice with Lewis lung carcinoma (LLC) or B16 melanoma were analyzed. The optical fingerprinting method relies on differences in the oxidation rate of a carbocyanine dye in the presence of blood plasma samples. Changes in fluorescence and absorption intensity were recorded photographically, enabling high-throughput analysis. The obtained images were digitized and the resulting dataset was processed using various statistical methods. Reaction-based optical fingerprinting achieved up to 100% observed accuracy in several classification tasks within the limited proof-of-concept dataset, distinguishing between healthy and diseased animals with transplanted tumors at different time points after tumor cell inoculation: 1 week for LLC, 2 weeks for B16, and 3 weeks for EMT-6. The same samples were simultaneously analyzed using TXRF, which also achieved 100% recognition accuracy when distinguishing between healthy animals and mice bearing LLC (after 1 and 2 weeks) or B16 melanoma (after 2 weeks). Although a direct combination of the reaction-based optical fingerprinting and TXRF analysis data into a single array did not consistently improve discrimination accuracy, the individual methods complement each other and enable effective screening of various cancer types. Overall, the kinetic based fingerprint method demonstrated significant potential in distinguishing between different types and stages of malignancies in mice.

Optical fingerprinting offers effective solutions to many practical problems that require distinguishing samples of similar composition. We are developing a kinetic version of optical fingerprinting based on conducting an indicator reaction in the presence of a sample and monitoring time-resolved optical changes during the reaction, which generates characteristic sample profiles that can be used for chemometric discrimination. This study investigates the influence of the choice of indicator reaction on the discrimination accuracy of various sample types, including irradiated foods (chicken breasts, potato tubers, and turkey liver), apple juices from different production years, natural waters, and model mixtures of pharmaceuticals. The method involved the oxidation of four heptamethine carbocyanine dyes by NaOCl or H2O2 in a 96-well plate with periodic absorption and emission measurements using a photographic method. The resulting kinetic profiles of the samples were processed using partial least squares - discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and logistic/softmax regression. At least one indicator reaction provided high discrimination accuracy (above 90%) for each sample type, but no single reaction was universally optimal for all tasks. PLS-DA proved to be the most effective method for data processing for binary classifications. The kinetic-based methods were compared with alternative approaches, including intrinsic spectra, antioxidant assay (FRAP), and 3,3',5,5'-tetramethylbenzidine (TMB) oxidation, with all methods tested on the same samples.​ The method is versatile and cost-effective, requires simple setup and minimal sample preparation, and is sensitive to minor compositional changes.

Mixed phosphonium-iodonium ylides are of interest as reactants for the synthesis of new heterocyclic compounds. Recently it has been shown that under irradiation the reactions of phosphonium-iodonium ylides occur with the formation of radicals. The radicals generated in the photolysis of the ylide itself and its fragments, diphenyliodonium salt and triphenylphosphine, or compounds participating in its reactions, dichloromethane and phenylacetylene, are studied with the use of PBN and DMPO spin traps. The obtained results confirm the radical mechanism of the ylide photodecomposition and have allowed us to specify the composition of the primary radicals generated in the photolysis. The unknown EPR parameters of spin adducts are determined for some radicals.

Extensive monitoring of water sources necessitates the development of inexpensive and effective methods for monitoring their pollution. A particularly challenging task is detecting a sudden release of contaminated effluents into a water supply. To solve this issue, we employ a reaction-based fingerprinting technique that is based on conducting an indicator reaction of oxidation of carbocyanine dyes in the presence of a sample. The absorbance and fluorescence intensity are measured periodically using cameras, and the obtained data are processed using machine learning techniques. Monitoring of clean tap or river water was simulated by sampling every few days. Artificial contamination of this water was modeled by adding diluted sewage water (4 different samples). As a result, the contaminated samples were displayed as outliers in the score plots. In both tap and river water, 0.1% vol of wastewater (1000-fold dilution) was detected. The accuracy of discrimination between polluted and unpolluted samples exceeded 90% using linear discriminant analysis (LDA) or softmax regression (SR). Thereby, an unexpected discharge of wastewater into a water source could be rapidly detected with simple instruments. Development of this approach will contribute to improving the accuracy and ease of detection of water source contamination, making environmental monitoring methods more reliable for the benefit of public health.

Fluorescent conjugates of carbocyanine dyes with a ligand selective to prostate-specific membrane antigen were accessed by either peptide synthesis or CuAAC methodology, with the latter being more promising. The introduction of a propargylamino moiety at the meso-position of the polymethine chain of the fluorophores afforded the alkyne counterparts for the CuAAC reaction toward the ligand bearing azido group. The photochemical studies showed that the quantum yields of the obtained conjugates exceeded those for the unmodified fluorophores by more than 20 times.

Food irradiation on an industrial scale calls for the development of rapid and inexpensive methods for the dose estimation after irradiation. An emerging solution to this problem is a reaction-based optical sensing strategy that is based on monitoring dose-dependent indicator reactions. In this study, raw chicken breast samples from three producers were irradiated with 1 MeV accelerated electrons, extracted with water for 24 h, and introduced into reactions of carbocyanine dyes with H2O2 or hypochlorite. The absorbance and fluorescence of the reaction mixtures in different spectral ranges were measured photographically as a function of time. Supervised machine learning methods allowed to confidently discriminate between the samples irradiated with 250, 1000, and 5000 Gy and non-irradiated samples provided that the samples irradiated with known doses were from the same producers as the unknown ones. Dose estimation for samples from an unknown producer could be implemented by constructing a database using samples from a larger number of producers.

For sensing small organic molecules, the tricarbocyanine derivatives are particularly efficient if contain at least two binding sites. As a step toward such ditopic structures, we synthesized the tricarbocyanines bearing ionogenic functional groups in the meso-position and studied their complexes with transition metals. New compounds exhibited a differential colorimetric response to individual pharmaceutical compounds tentatively due to the formation of mixed-ligand complexes.

Substitution reactions in carbocyanine dyes are used to determine nucleophilic compounds. The interaction of a chlorine-containing carbocyanine dye with a number of medicinal substances is studied. It is shown that, in the reaction with isoniazid in the presence of a surfactant, this dye selectively changes color from yellow-green to violet. The formation of a product of the substitution of chlorine for isoniazid is proven by chromatography–mass spectrometry. The reaction proceeds in 20 min in the presence of 1 mM cetyltrimethylammonium bromide. The limit of detection for isoniazid in water by the photometric method is 10 μg/mL and in diluted artificial urine using fluorimetry, 0.3 μg/mL. The procedure does not use full-spectrum equipment, which simplifies the determination.

Food irradiation is becoming increasingly popular in many countries for preserving and extending the shelf life of foods, which creates a demand for express methods for the detection of absorbed doses. This paper proposes an innovative method for the estimation of the dose absorbed by X-rayed beef samples using a reaction -based optical sensing technique that was proposed earlier by our team for the estimation of the dose absorbed by raw potatoes. Potato and beef samples were exposed to X-ray irradiation at 100 and 1000 Gy and then extracted by water at 23 C-degrees for 24 h or 60/70 C-degrees for 1 h. The resulting solutions were introduced to the reaction mixtures of dyes (carbocyanines, Rhodamines, or Crystal Violet) with oxidants (hypochlorite, bromate, or hydrogen peroxide). The fluorescence intensity and absorbance of the mixtures were periodically measured photographically using visualizers. The data were processed using linear discriminant analysis (LDA) and k -nearest neighbors algorithm (kNN). Using the most efficient individual reactions, the doses can be recognized with a 90-100% accuracy, and the combinations of up to 5 reactions can improve the accuracy to 100%. The protocol is simple and rapid: sample extraction time and indicator reactions take not more than 1 h each. The proposed method potentially has a wide area of applications ranging from plants to animal products.

The condensation of diethyl phosphite with aldehydes and cyclic ketones under conditions of thermal catalysis and microwave radiation (MW) afforded new amino phosphonates based on secondary amines, including those containing gem-dichlorocyclopropane and cyclic acetal fragments. The optimization of conditions for obtaining the target products using MW radiation showed that dialkylamines are more active than the secondary amines used.

The reactivity of ylides possessing additional iodonium functionality is driven by the departure of the iodonium group, which generates highly reactive intermediates. The scope of these reactions depends on both the nature of the reacting partner and the functional groups present at the ylidic center. In this study, we investigate the reactivity of phosphonium-iodonium ylides, where the ylidic carbon atom is bonded to a cyclic phenoxaphosphonium moiety and various electron-withdrawing substituents. The study examines these ylides in reactions with nitriles and alkynes, continuing our investigation of acyclic phosphonium-iodonium ylides with triple-bond-containing compounds. The incorporation of phosphorus into a cyclic structure reveals new bond-making and bond-breaking patterns in reactions with alkynes, leading to novel reaction pathway and the formation of enone-functionalized phosphonates. Phenoxaphosphonium-iodonium ylides and furans have been shown to have antiproliferative activity in vitro against several human cancer cell lines.

Treatment of mixed phosphonium-iodonium ylides featuring a six-membered phenoxaphosphonium fragment with aqueous tetrafluoroboronic acid induces a rearrangement, resulting in expansion of the phosphacycle and oxidation of the phosphorus atom. The target difficult-to-access dibenzo[b,f][1,4]oxaphosphepine oxides (3 examples) were isolated in excellent yields (up to 95%) as mixtures of stereoisomers. Hydrolysis of a five-membered mixed ylide, a dibenzophosphole derivative, predominantly preserves the phosphole system with cycle expansion occurring as a side process.

Annulation of mixed phosponium-iodonium ylides and compounds with a triple bond is an interesting example of the synthesis of different types of heterocycles in one-pot, metal-free systems at ambient temperature to give substituted oxazoles in the reaction with nitriles and phosphorus-containing lambda(5)-phosphinolines and substituted furans in the reaction with acetylenes. The iodonium group in the mixed ylides provides the possibility for the radical initiation of the reaction. Herein, we investigated the generation of primary radicals and the formation of phosphorus-containing products in the photolysis of benzoyl phosphonium-iodonium ylide alone and in its reaction with acetylenes in DCM by EPR and P-31 NMR spectroscopies with the use of two most popular spin traps, PBN and DMPO. The results allowed us to account the crucial difference in the registered radicals in the two systems for the aggregation of the components, with ylide molecules forming a core and acetylene molecules being a shell of the aggregates in DCM, in which the annulation occurs. The peculiarities of the reactions of PBN and DMPO with generated radicals are discussed.

For the purpose of imaging hydrophilic drugs, aggregates of gentamicin and vinorelbine with carbocyanine dyes fluorescing in the near-infrared region of the spectrum and a laurate ion as a counterion are obtained. To isolate the aggregates, precipitation from an aqueous solution of components is used. The size of the aggregates with gentamicin range from 200 to 600 nm; with vinorelbine, from 400 to 1000 nm; the surface ζ potential varies in the range of –15…–5 mV. The aggregates are sorbed by the subcutaneous fatty tissue, muscle, bone, and endothelial tissues of chickens. In the future, the resulting aggregates can be used to visualize drug delivery to the tissues of living organisms.

Mixed phosphonium-iodonium ylides effectively undergo the photochemical reaction of heterocyclization. For most mixed phosphonium-iodonium ylides, the main stage of photolysis was the homolytic cleavage of the C—I bond of the ylide molecule with the formation of radicals. ESR spectroscopy was used to study radicals formed during the photolysis of the mixed benzoyl-substituted phosphonium-iodonium ylide in acetonitrile and alcohols. The hyperfine coupling constants of the registered radicals were determined and their structures were proposed.

Water quality control employs techniques mostly targeting individual analytes; group detection is also practiced, but the choice of group methods is limited, which supports interest in developing such methods. We have examined the interaction of hypochlorite with a chlorine-containing heptamethine carbocyanine dye in the presence of 30 organic and inorganic model analytes that were found to induce diverse color changes in the system. The main supposed mechanisms are retardation of the dye oxidation with hypochlorite (presumably by scavenging chlorine radicals) and substitution of chlorine atom in the dye by the most nucleophilic analytes (amines, amino acids, proteins, DNA, phenol). The grass-green substitution product is more contrastingly visible against the dark-purple hypochlorite oxidation product of the dye than against the original emerald-green dye. The indicator reaction is monitored photographically for 10–40 min and the images are processed using principal component analysis (PCA) or linear discriminant analysis (LDA), allowing for data convolution for the complex color transitions. Nitrogen compounds are discriminated from the others, and more reactive analytes (tryptophan, cysteine, bovine serum albumin, and DNA) are detected in the presence of less reactive ones in natural water. The system is promising for the development of group assays for dissolved organic matter and the discrimination of water samples.

Optical sensor arrays are widely used in obtaining fingerprints of samples, allowing for solutions of recognition and identification problems. An approach to extending the functionality of the sensor arrays is using a kinetic factor by conducting indicator reactions that proceed at measurable rates. In this study, we propose a method for the discrimination of proteins based on their oxidation by sodium hypochlorite with the formation of the products, which, in turn, feature oxidation properties. As reducing agents to visualize these products, carbocyanine dyes IR-783 and Cy5.5-COOH are added to the reaction mixture at pH 5.3, and different spectral characteristics are registered every several minutes (absorbance in the visible region and fluorescence under excitation by UV (254 and 365 nm) and red light). The intensities of the photographic images of the 96-well plate are processed by principal component analysis (PCA) and linear discriminant analysis (LDA). Six model proteins (bovine and human serum albumins, γ-globulin, lysozyme, pepsin, and proteinase K) and 10 rennet samples (mixtures of chymosin and pepsin from different manufacturers) are recognized by the proposed method. The method is rapid and simple and uses only commercially available reagents.