Determination of deferiprone in urine and serum using a terbium-sensitized luminescence method

A versatile ratiometric fluorescence nanoprobe for the determination of clonazepam in patients' plasma samples

Despite the necessity of the study of therapeutic drug monitoring of clonazepam (CLZ), there are only a few fast detection methods available for determining CLZ in biological media. This study aims to develop a cost-effective and ratiometric probe for the quantification of CLZ in plasma samples. Fluorescent polydopamine nanoparticles were produced through a self-polymerization process at a pH of 8.5. Rhodamine B molecules were employed as a fluorescent reference material, emitting stable fluorescence in the visible range. The fabricated probe exhibited a specific detection capability for CLZ. The fluorescence emission of the probe was enhanced in two concentration ranges: from 50 ng/mL to 1.0 μg/mL and from 1.0 to 15.0 μg/mL with a lower limit of quantification of 50 ng/mL, indicating the sensitivity of the probe for detecting CLZ plasma levels. The accuracy of the probe is favorable which could be recommended for CLZ monitoring in the biological media. Furthermore, this probe is highly specific towards CLZ in the presence of various interfering agents which is mainly caused by its ratiometric nature. The developed platform showed high reliability in quantifying CLZ concentrations in patients' plasma samples. Hence, the fabricated probe could be recommended as a reliable method for the routine detection of CLZ in clinical settings.

A dual-emission ratiometric fluorescent biosensor for ultrasensitive detection of glibenclamide using S-CDs/CdS quantum dots

In the present work, sulfide-doped carbon dots (S-CDs)/cadmium sulfide quantum dots (CdS QDs) ratiometric fluorescent nanosensor has been developed for sensitive and selective determination of glibenclamide (GLC) in biological fluids. The method was based on the quenching effect of GLC on the dual-emission intensity of the S-CDs/CdS QDs system at 420 nm and 650 nm, which are related to S-CDs and CdS QDs, respectively. The fluorimetric data analysis indicated that the fluorescence signals of the system were quenched by adding GLC in a concentration-dependent manner. A good linear relationship was observed between GLC concentration and the quenched fluorescence intensity of the S-CDs/CdS QDs in the range of 0.3 nM-10.0 μM. The limit of detection (LOD) value was estimated to be 0.12 nM. Furthermore, under optimum conditions, GLC was detected in spiked human serum sample (as real media) using the developed ratiometric nanosensor with an accuracy of 99.6%. According to the results, the developed dual-emission system can be used as a reliable method for the quantitative detection of GLC in biological samples.

Electrochemical Biosensors as a Novel Platform in the Identification of Listeriosis Infection

Listeria monocytogenes (L.M.) is a gram-positive bacillus with wide distribution in the environment. This bacterium contaminates water sources and food products and can be transmitted to the human population. The infection caused by L.M. is called listeriosis and is common in pregnant women, immune-deficient patients, and older adults. Based on the released statistics, listeriosis has a high rate of hospitalization and mortality; thus, rapid and timely detection of food contamination and listeriosis cases is necessary. During the last few decades, biosensors have been used for the detection and monitoring of varied bacteria species. These devices are detection platforms with great sensitivity and low detection limits. Among different types of biosensors, electrochemical biosensors have a high capability to circumvent several drawbacks associated with the application of conventional laboratory techniques. In this review article, different electrochemical biosensor types used for the detection of listeriosis were discussed in terms of actuators, bioreceptors, specific working electrodes, and signal amplification. We hope that this review will facilitate researchers to access a complete and comprehensive template for pathogen detection based on the different formats of electrochemical biosensors.

Spectrofluorimetric Method for Monitoring Methotrexate in Patients' Plasma Samples and Cell Lysates Using Highly Fluorescent Carbon Dots

For the first time, nitrogen, sulfur, phosphorus, and boron-doped carbon dots (N, S, P, B-codoped CDs) were synthesized through a hydrothermal reaction. The produced CDs were utilized to develop an optical sensor to determine methotrexate (MTX) in cell lysates and patients' plasma samples. Basically, in the presence of MTX, the fluorescence emission of the CD-based probe was quenched. Under optimum conditions, a good proportional relationship was obtained between the quenched fluorescence signal and MTX concentrations from 74.9 ng/mL to 99.9 µg/mL with a limit of detection of 74.9 ng/mL. The developed nanoprobe provided a wide linear range and high accuracy and was successfully utilized in the routine therapeutic drug monitoring of MTX in plasma samples. The obtained results proposed the developed nanoprobe for the on-time and specific detection of MTX in blood samples. As another application, N, S, P, B-codoped CDs were utilized for bioimaging MCF-7 cancer cells and could be proposed as efficient bioimaging agents for tumor cells.

Simple fluorescence chemosensor for the detection of calcium ions in water samples and its application in bio-imaging of cancer cells

This article describes the design, synthesis and characterization of a sensor suitable for practical measurement of ionized calcium in water samples and cancer cells. Calcium is an important ion in living organs and works as a messenger in several cellular functions. A lack of Ca ions interrupts the immune system and can lead to several diseases. A novel magnetic-polydopamine nanoparticle (PDNP)/rhodamine B (RhB)/folic acid (FA) nanoparticle was developed for the determination of calcium ions in MCF 7 cell lysates and water samples. Furthermore, the produced nanoparticle was employed for bioimaging of folate receptor (FR)-overexpressed cancer cells. This nanoprobe displayed a bright photoluminescence emission at 576 nm under an excitation wavelength of 420 nm. In the presence of calcium ions, the fluorescence emission of the MNPs-PDNPs/RhB/FA probe was proportionally decreased from 20 ng mL-1 to 100 ng mL-1 and 0.5 μg mL-1 to 20 μg mL-1 with a lower limit of quantification (LLOQ) of about 20 ng mL-1. The developed sensor showed a low-interference manner in the presence of possible coexistence interfering ions. In addition, this nanomaterial showed excellent biocompatibility with favorable differentiation ability to attach to the FR-positive cancer cells. The MNPs-PDNPs/RhB/FA nanoparticle has been utilized for bioimaging of the MCF 7 cell with favorable differentiation ability.

Quality by design approach for green HPLC method development for simultaneous analysis of two thalassemia drugs in biological fluid with pharmacokinetic study

This work implements a combined experimental approach of analytical quality-by-design (AQbD) and green analytical chemistry (GAC) to develop an HPLC method for simultaneous determination of the two thalassemia drugs, deferasirox (DFX) and deferiprone (DFP), in biological fluid for the first time. This integration was designed to maximize efficiency and minimize environmental impacts, as well as energy and solvent consumption. To accomplish this goal, an analytical quality-by-design approach was performed, beginning with quality risk assessment and scouting analysis, followed by Placket-Burman design screening for five chromatographic parameters. Critical method parameters were thoroughly recognized and then optimized by using a two levels-three factors custom experimental design to evaluate the optimum conditions that achieved the highest resolution with acceptable peak symmetry within the shortest run time. The desirability function was used to define the optimal chromatographic conditions, and the optimal separation was achieved using an XBridge® HPLC RP-C18 (4.6 × 250 mm, 5 μm) column with ethanol : acidic water at pH 3.0 adjusted by phosphoric acid in the ratio of (70 : 30, v/v) as the mobile phase at a flow rate of 1 mL min^-1 with UV detection at 225 nm at a temperature of 25 °C. Linearity was obtained over the concentration range of 0.30-20.00 μg mL^-1 and 0.20-20.00 μg mL^-1 for DFX and DFP, respectively, using 20.00 μg mL^-1 ibuprofen (IBF) as an internal standard. The established method's greenness profile was evaluated and measured using various assessment tools, and the developed method was green. For the validation of the developed method, FDA recommendations were followed, and all the results obtained met the acceptance criteria. The suggested method was successfully used to study the pharmacokinetic parameters of DFX and DFP in rat plasma. Due to the substantial increase in bioavailability of the two iron chelating drugs, the results from this study strongly recommend their co-administration.

Early stage evaluation of colon cancer using tungsten disulfide quantum dots and bacteriophage nano-biocomposite as an efficient electrochemical platform

Background

Recently, biosensors have become popular analytical tools for small analytes due to their high sensitivity and wide analytical range. In the present work, development of a novel biosensing method based on tungsten disulfide quantum dots (WS2 QDs)-Au for rapidly and selectively detecting c-Met protein is introduced. As a proof of concept, M13 bacteriophage-based biosensors were used for the electrochemical detection of c-Met protein as a colon cancer biomarker.

Method

The M13 bacteriophage (virus), as the biorecognition element, was immobilized on glassy carbon electrodes which were modified by WS2 QDs-functionalized gold nanoparticles. The stepwise presence of the WS2 QDs, gold nanoparticles, and immobilized phage on glassy carbon electrodes were confirmed by scanning electron microscope (SEM) and square wave voltammetry (SWV) technique.

Results

The designed biosensor was applied to measure the amount of c-Met protein in standard solutions, and consequently the desirable detection limit of 1 pg was obtained. Finally, as a proof of concept, the developed platform was used for the evaluation of c-Met protein in serum samples of colon cancer-suffering patients and the results were compared with the results of the common Elisa kit.

Conclusions

As an interesting part of this study, some concentrations of the c-Met protein in colon cancer serum samples which could not be determined by Elisa, were easily analyzed by the developed bioassay system. The developed bioassay system has great potential to application in biomedical laboratories.

Graphical Abstract

Applications of scaffold-based advanced materials in biomedical sensing

There have been many efforts to synthesize advanced materials that are capable of real-time specific recognition of a molecular target, and allow the quantification of a variety of biomolecules. Scaffold materials have a porous structure, with a high surface area and their intrinsic nanocavities can accommodate cells and macromolecules. The three-dimensional structure (3D) of scaffolds serves not only as a fibrous structure for cell adhesion and growth in tissue engineering, but can also provide the controlled release of drugs and other molecules for biomedical applications. There has been a limited number of reports on the use of scaffold materials in biomedical sensing applications. This review highlights the potential of scaffold materials in the improvement of sensing platforms and summarizes the progress in the application of novel scaffold-based materials as sensor, and discusses their advantages and limitations. Furthermore, the influence of the scaffold materials on the monitoring of infectious diseases such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and bacterial infections, was reviewed.

Ultrasensitive fluorescence detection of antitumor drug methotrexate based on a terbium-doped silica dendritic probe

A novel strategy was developed for the detection of methotrexate (MTX) via the quenching effect of MTX on the fluorescence intensity of terbium-doped dendritic silica particles (Tb@KCC-1). The fluorescence intensity of Tb@KCC-1 can be effectively quenched by MTX at 546 nm under an excitation wavelength of 233 nm. The quenched fluorescence is proportional to the amount of MTX in both plasma and exhaled breath condensate (EBC) samples. Under the optimal conditions, the linear dynamic ranges of the developed method were 44 nM to 2.2 μM for EBC, 44 nM to 0.22 μM and 0.22-2.2 μM for plasma samples. The limit of detection (LOD) and limit of quantification (LOQ) in both plasma and EBC media are 35 and 116 nM, respectively. The developed method has the benefits of fast analysis time, simple approach, high specificity, and sensitivity for the detection of MTX in both media. This nanoprobe has been successfully utilized for the quantification of MTX in patients' plasma and spiked EBC samples, proving the applicability of the nanoprobe for MTX detection in real samples.

Synthesis of folic acid functionalized terbium-doped dendritic fibrous nano-silica and Interaction with HEK 293 normal, MDA breast cancer and HT 29 colon cancer cells

A novel folic acid functionalized terbium-doped dendritic fibrous nanoparticle (Tb@KCC-1-NH₂ -FA) with high surface area was synthesized using a novel hydrothermal protocol. In the present work, we report the fluorescent Tb-doted nanomaterial with emission wavelength at 497 nm which confirms the formation of Tb@KCC-1-NH₂ -FA. Synthesized nanoparticles were investigated through transmission electron microscope, field emission scanning electron Microscopy, Fourier transform infrared spectra, Brunauer-Emmett-Teller, energy dispersive X-ray, Zeta potential and particle size distribution values and AFM (Atomic force microscopy) techniques. Specially, our desired nanomaterial which has FA moieties on the surface of Tb@KCC-1-NH2-FA where interact with folate receptor (FR) which there is on the surface of the various cancer cells. For this purpose, fluorescence microscopy images were used to prove the uptake of FA based nanomaterial with FR-positive MDA breast cancer and HT 29 colon cancer cells. Also HEK 293 normal cells as FR-negative cells verified the specificity of our desired nanomaterial toward the FR-positive cells. The cytotoxicity survey of Tb@KCC-1-NH₂ -FA was examined by MTT assays against MDA breast cancer, HT 29 colon cancer and HEK 293 Normal cell lines which confirmed their biocompatible nature with any significant cytotoxic effects even for concentration higher than 900 μg/mL which could be used as a non-toxic catalyst or carrier in biological ambient. Hence, Tb@KCC-1-NH₂ -FA were synthesized using green and hydrothermal method; the process was simple with good productivity and desired nanocomposite was non-toxic.

Developing an Analytical Method Based on Graphene Quantum Dots for Quantification of Deferiprone in Plasma

In the world of nanotechnology, graphene quantum dots (GQDs) have been considerably employed in numerous optical sensing and bioanalytical applications. Herein, a simple and cost-efficient methodology was developed to the quantification of deferiprone in plasma samples by utilizing the selective interaction of the GQDs and drug in the presence of Fe³⁺ ions. GQDs were synthesized by a bottom-up technique as an advantageous fluorescent probe. Increasing levels of deferiprone ranging from 5 to 50 mg.L^-1, leads to significant fluorescence quenching of GQDs. In addition, the calibration curve was revealed a linear response in this range with a sensitivity of 5 mg.L^-1. The method validation was carried out according to the FDA guidelines to confirm the accuracy, precision, stability and selectivity of the developed method. The results show that this green and low-cost fluorescent probe could be used for the analysis of deferiprone.

Spectrofluorimetric cytosensing of colorectal cancer cells using terbium-doped dendritic fibrous nano-silica functionalized by folic acid: A novel optical cytosensor for cancer detection

A novel fluorescent probe for detection of HT 29 cancer cells was developed based on terbium-doped dendritic fibrous nanosilica functionalized by folic acid (Tb@KCC-1-NH₂-FA). Using this probe, fluorescence signals was emitted by Tb@KCC-1-NH₂-FA at 490 nm by applying 380 nm as excitation wavelength. The reported probe is based on the interaction between FA decorated on the surface of Tb@KCC-1-NH₂-FA and folate receptor (FR) which is overexpressed on the surface of the most of cancer cells. Fluorescence microscopy and flow cytometry were utilized to verify the uptake of Tb@KCC-1-NH₂-FA with FR-positive HT 29 cancer cells. The specificity of Tb@KCC-1-NH₂-FA towards FR-positive cells was approved by staining HEK 293 cells as FR-negative cells with Tb@KCC-1-NH₂-FA which obtained results approved selective differentiation of normal cells with the FA-decorated nanomaterials. The cytotoxicity of Tb@KCC-1-NH₂-FA was evaluated by MTT assay which confirmed their biocompatible nature. Under optimum conditions, this cytosensor is able to detect HT 29 colon cancer from 500 to 6.5 × 10³ cells/mL with lower limit of detection (LLOQ) of 500 cells/mL. Due to the room temperature stability of Tb@KCC-1-NH₂-FA, this cytosensor could be developed in a simple way with exceptional specificity which may show potential applications for early stage detection of colon cancer.

A ratiometric fluorometric and colorimetric probe for the β-thalassemia drug deferiprone based on the use of gold nanoclusters and carbon dots

A turn-on fluorometric probe is described for the β-thalassemia drug deferiprone (DFP). The probe is making use of carbon dots (C-dots) and gold nanoclusters (AuNCs) which, under 340-nm excitation, display dual emission with peaks at 445 and 592 nm. The orange fluorescence of AuNCs is quenched after the addition of Fe(III), but recovered on addition of DFP. The blue fluorescence of the C-dots, in contrast, remains unchanged. The Fe(III)-DFP complex undergoes intermolecular electron transfer under UV excitation and displays only weak peaks in the UV region. The ratio of the two fluorescences is measured which makes the probe intrinsically self-calibrated. Colorimetry is best performed at a wavelength of 280 nm. The ratio of fluorescences increases linearly in the 0.1-80 μM DFP concentration range, and the detection limit is 0.1 μM. The respective figures for colorimetry are 2.5-120 μM and 0.3 μM. The probe is highly selective for DFP. Thus, it possesses a large potential for detection of DFP in serum. Graphical abstract The orange fluorescence of gold nanoclusters (AuNCs) is quenched by Fe³⁺ ions but recovered on addition of deferiprone (DFP), while the change of blue fluorescence in carbon dots (C-dots) is minimal. Moreover, the Fe(III)-DFP complex undergoes intermolecular electron transfer under ultraviolet (UV) irradiation, and absorption spectra can be observed in the presence of Fe(III)-DFP detected by UV scanning. Thus, a ratiometric fluorometric and colorimetric assay is developed for DFP.