Electrochemical polymerized 5-amino-2-mercapto-1,3,4-thiadiazole modified single use sensors for detection of quercetin

Electrochemical preparation and the characterizations of poly(3,5-diamino 1,2,4-triazole) film for the selective determination of pyridoxine in pharmaceutical formulations

This work describes the synthesis and characterization of a polymeric film of 3,5-diamino 1,2,4-triazole on a pencil graphite electrode for the selective sensing of pyridoxine (PY). The PGE was modified using the electropolymerization process by the potentiodynamic method. The polymerized electrode (PDAT/PGE) was characterized by IR, SEM, AFM, cyclic voltammetry, and electrochemical impedance spectroscopy. PY undergoes irreversible oxidation at 0.79 V on PDAT/PGE in phosphate buffer of pH 5. Using the differential pulse voltammetric technique (DPV), PY showed a linear range from 5 to 950 μM with a lower detection limit of 2.96 μM. The PDAT/PGE was applied for the analytical determination of PY in pharmaceutical tablets with good recovery.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11696-023-02777-5.

Electrochemical study of 2-amino-5-mercapto-1,3,4-thiadiazole in the absence and presence of p-benzoquinone: an efficient strategy for the electrosynthesis of new 1,3,4-thiadiazole derivatives

In this study, first, the electrochemical behavior of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) was fully investigated in the absence and presence of electrochemically generated p-benzoquinone (p-BQ, which is the oxidized form of hydroquinone), as an electrophile, via cyclic voltammetry (CV) at a glassy carbon electrode (GCE) and in an acetic acid buffer (0.2 M)/ethanol solution mixture. Then, an E-pH diagram was proposed for different structures of AMT at various pH values. The obtained voltammograms also exhibited an "electron transfer + chemical reaction" (EC) mechanism. Besides the voltammetric exploration, electrosynthesis of new 1,3,4-thiadiazole derivatives was conducted by constant current electrolysis (CCE) as a facile and cost-effective method for the formation of S-S and S-C bonds. Finally, the biological activity of products was also analyzed via an in silico method.

Biogenic synthesis of carbon quantum dots from garlic peel bio-waste for use as a fluorescent probe for sensing of quercetin

Highly fluorescent and water-soluble carbon quantum dots (CQDs) were synthesized from the bio-waste source of garlic peels (renovation of bio-waste into bio-asset) using a controlled carbonization method. Synthesized CQDs were characterized by various analytical methods and explored as a fluorogenic probe for the recognition of quercetin (QT). UV-Vis result shows an absorption maximum at 275 nm attributed to the conjugation of C=C and C=O of CQDs and demonstrates a blue emission in the range of 330-410 nm. Selectivity was performed with various biomolecules, except for QT, all other do not exhibit any considerable change in the fluorescence of CQDs. On the interaction with QT, emission was completely quenched due to FET, confirming the high selective to QT. Effect of pH, sensitivity, and stability studies displayed excellent results under optimized conditions. The LOD fluorescent probe was found to be 6.73 μM. Our approach may suggest a new platform for the development of quick and low-cost CQDs-based sensors for environmental and biological purposes.

Electrochemical determination of anticancer drug Bendamustine and its interaction with double strand DNA in the absence and presence of quercetin

Studies based on drug-DNA interactions, especially anticancer drug-DNA interactions, are of great importance for the method development. It is thought that single-use electrodes, which give fast, cheap and reproducible results, will make a great contribution to the chip technology for the development of individual patient analysis in the future. It is known that antioxidants reduce carcinogenesis caused by oxidative stress with their radical scavenging effects. Literature shows that quercetin (QRCT) exhibits anticancer activity by preventing oxidative cell damage as an effective radical scavenger. In this study, Bendamustine (BND), an anticancer drug, which is used in different blood cancer types, was electrochemically determined and the toxicity degree was calculated by examining the interaction of the drug with DNA in the absence and presence of QRCT, which is the first examination in the literature. Limit of detection and quantification for BND was calculated as 6.0 and 20.0 μg/mL respectively by using the equation I = 0.029 × C_BND+ 1.197, (R² = 0.997). We found that QRCT prevents the interaction between BND and DNA because of its strong interaction with DNA.

Borate-modified carbon dots as a probe for quercetin in plants

Schematic presentation of the PBA-CDs enhancing the fluorescence of quercetin in contrast to N-CDs.

Development of Aloe vera-titanium oxide-based ultrasensitive sensor for the quantification of quercetin

In the present work, a novel sensor developed for the quantification of quercetin (QRC) is being reported. Due to synergistic effects of Aloe vera and titanium oxide, voltammetric performance of the developed sensor (ALV-TiO2/glassy carbon electrode) was greatly enhanced. The fabricated sensor was characterized by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray, and electrochemical impedance spectroscopy. The sensor was applied to study electrochemical behavior of QRC using square wave voltammetry. Under optimal condition, the developed sensor exhibited a linear response in the range of 3.3 × 10-7 to 2.31 × 10-6 µM with a detection limit of 0.8 nM. The analytical utility of the proposed sensor was justified by applying it for the analysis of QRC in real samples.

Highly sensitive and selective optosensing of quercetin based on novel complexation with yttrium ions

A simple and fast method was developed for the determination of quercetin. The concentration of quercetin can be determined based on the fluorescence emission resulting from the coordinative interactions between quercetin and the yttrium ion (Y³⁺). Notably, a portable platform to quantitatively analyze quercetin was constructed. This platform incorporates our custom-built homemade reader based on a photodiode, and Arduino hardware, which accepts a paper ribbon on which Y³⁺ is deposited as an input. In addition, the color change of the paper ribbon was identified using a smartphone via the hue values of the photographs. The limits of detection for quercetin using spectroscopy, a smartphone, and a custom-built reader were calculated to be 27, 110, and 129 nM, respectively. The use of a custom-built device and a smartphone for detecting quercetin via fluorescence from the prepared paper ribbon reduces the time and cost of quercetin detection. This approach could be employed for on-site sensing of quercetin in real samples.

Sr-Doped NiO3 nanorods synthesized by a simple sonochemical method as excellent materials for voltammetric determination of quercetin

A fabricated Sr-doped NiO₃ nanorod-modified GCE was developed for electrochemical sensing of quercetin.

Modern Assay Techniques for Cancer Drugs: Electroanalytical and Liquid Chromatography Methods

In the past decades, patients who have chemotherapy treatment have considerably increased number. At this point, the development of rapid precise, and reliable methods are very important to analyze cancer drugs from their dosage forms, animals or human biological samples. Among all the analytical methods, electrochemical methods hold an important position with their unique properties such as specificity in the biological recognition process, fast response, and their reliability and do not need a pretreatment process. Chromatographic methods are also used in a wide range of analytical applications for the analyses of anticancer drugs. The power of chromatography comes from its ability to separate a mixture of analytes and determination of their concentrations. Chromatographic techniques can mainly be divided into gas, liquid, and supercritical fluid chromatography. In the frame of this information, this review is aimed to provide basic principles of electroanalytical and high-performance liquid chromatography methods for the analysis of cancer drugs. In addition, some selected applications for electrochemistry-related techniques and high-performance liquid chromatography, for the determination of anti-cancer pharmaceuticals published in the last five years are also discussed.

Efficient Enrichment and Analysis of Vicinal-Diol-Containing Flavonoid Molecules Using Boronic-Acid-Functionalized Particles and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Detection and quantitation of flavonoids are relatively difficult compared to those of other small-molecule analytes because flavonoids undergo rapid metabolic processes, resulting in their elimination from the body. Here, we report an efficient enrichment method for facilitating the analysis of vicinal-diol-containing flavonoid molecules using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. In our strategy, boronic-acid-functionalized polyacrylamide particles were used, where boronic acids bound to vicinal diols to form boronate monoesters at basic pH. This complex remained intact during the enrichment processes, and the vicinal-diol-containing flavonoids were easily separated by centrifugation and subsequent acidic treatments. The selectivity and limit of detection of our strategy were confirmed by mass spectrometry analysis, and the validity was assessed by performing the detection and quantitation of quercetin in mouse organs.

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

Due to their electrochemical and economical characteristics, pencil graphite electrodes (PGEs) gained in recent years a large applicability to the analysis of various types of inorganic and organic compounds from very different matrices. The electrode material of this type of working electrodes is constituted by the well-known and easy commercially available graphite pencil leads. Thus, PGEs are cheap and user-friendly and can be employed as disposable electrodes avoiding the time-consuming step of solid electrodes surface cleaning between measurements. When compared to other working electrodes PGEs present lower background currents, higher sensitivity, good reproducibility, and an adjustable electroactive surface area, permitting the analysis of low concentrations and small sample volumes without any deposition/preconcentration step. Therefore, this paper presents a detailed overview of the PGEs characteristics, designs and applications of bare, and electrochemically pretreated and chemically modified PGEs along with the corresponding performance characteristics like linear range and detection limit. Techniques used for bare or modified PGEs surface characterization are also reviewed.

Sensitive Voltammetric Determination of Natural Flavonoid Quercetin on a Disposable Graphite Lead

In this paper, a pencil graphite electrode was pretreated using chronoamperometry technique in phosphate buffer solution (pH=7.0) for sensitive determination of quercetin. Oxidation of quercetin was investigated using pretreated pencil graphite electrode and anodic stripping differential pulse voltammetry. Under optimal conditions, the anodic current of quercetin exhibited linear response to its concentration in the range from 0.001 to 1.5 µmol/L with the limit of detection of 0.3·10^-3 µmol/L. The proposed method was successfully applied for the determination of quercetin in cranberry and blackcurrant juices with recovery rate from 93.2 to 94.7%. Solid-phase extraction was found to be necessary prior to voltammetric determination of quercetin in fruit juice samples using pretreated pencil graphite electrode.

Highly luminescent organosilane-functionalized carbon dots as a nanosensor for sensitive and selective detection of quercetin in aqueous solution

The organosilane-functionalized carbon dots (SiCDs) were synthesized using citric acid with N-(b-aminoethyl)-g-aminopropyl methyldimethoxy silane (AEAPMS). The as-synthesized SiCDs were characterized by IR, TEM, XPS, NMR and fluorescence. The SiCDs showed a strong emission at 455 nm with excitation at 365 nm. The SiCDs exhibited analytical potential as sensing probes for quercetin (QCT) determination. pH effect, temperature effect, interferences, and analytical performance of the method were investigated. It suggested that SiCDs exhibited high sensitivity and selectivity toward QCT: the linear ranges of SiCDs were estimated to be 0-40 μM while the limit of detection (LOD) was calculated to be 79 nM.