Differentiation and targeting of HT 29 cancer cells based on folate bioreceptor using cysteamine functionalized gold nano-leaf

A ratiometric electrochemical probe for the quantification of apixaban in unprocessed plasma samples using carbon aerogel/BFO modified glassy carbon electrodes

A novel electrochemical probe was established for the quantification of apixaban (APX) in unprocessed plasma samples. Efficiently oxidized graphene oxide aerogels (EEGO-AGs) and nano-sized Bi2Fe4O9 (BFO) particles were electrodeposited on the surface of a glassy carbon electrode (GCE). In this work, a ratiometric electrochemical method was introduced for APX detection to enhance the specificity of the probe in plasma samples. The fabricated ratiometric probe was employed for the indirect detection determination of APX using K3[Fe(CN)6]/K4[Fe(CN)6] as the redox pair. The differential pulse voltammetry technique was used to record the current alteration of the BFO/EEGO-AG-functionalized GCE probe at various APX concentrations. The probe response was proportional to the APX concentrations from 10 ng mL-1 to 10 μg mL-1 with a low limit of quantification (LLOQ) of 10 ng mL-1. After validation, this method was successfully utilized for the determination of APX in patients' plasma samples who have taken APX regularly. The fabricated chemosensor detected APX concentrations in unprocessed plasma samples with high selectivity, resulting from the physical filtering antifouling activity of aerogels.

Synthesis and characterization of folate-functionalized silica-based materials and application for bioimaging of cancer cells

Early-stage detection is a vital factor in the later treatment and prognosis of cancer. Enhancing the sensitivity and specificity of the cancer detection pathological and experimental approaches can affect the morbidity and mortality of this disease. A folic acid (FA)-functionalized silica quantum dots (SiQDs)/KCC-NH₂@SiO₂ nanomaterials were synthesized and characterized as a bioimaging agent of the MCF 7 cancer cells. These nanoparticles showed biocompatible nature with specificity towards folate receptor (FR)-overexpressed MCF 7 cancer cells. Viability findings suggested that the SiQDs/KCC-NH₂@SiO₂/FA nanomaterials have nontoxic nature towards the cells in the concentration of 200 μg/mL. Fluorescence microscopy images were utilized to estimate the cell internalization of the nanoparticles and further verified by the flow cytometry technique. The differentiation ability of the nanoparticles was also approved by incubation with FR-negative HEK 293 normal cells. The SiQDs/KCC-NH₂@SiO₂/FA nanoparticle exhibited high stability, bright and high quantum yield fluorescence emission, proposing as a high-quality material for in vivo bioimaging of FR-overexpressed circulating tumoral cancer cells (CTCs).

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.

Concanavalin A-conjugated gold nanoparticle/silica quantum dot (AuNPs/SiQDs-Con A)-based platform as a fluorescent nanoprobe for the bioimaging of glycan-positive cancer cells

The glycan receptor is a glycosylphosphatidylinositol glycoprotein that is overexpressed on the surface of various cancer cells and has been utilized for wide applications. In the present work, the surface of citrate-capped gold nanoparticles (cit-AuNPs) was modified with mercaptopropionic acid (MPA) molecules to provide carboxylic groups for secondary functionalization with amine anchored-silica quantum dots (Si-NH₂ QDs) to produce cit-AuNPs-MPA/Si-NH₂ QDs fluorescent nanoparticles. Concanavalin A (Con A) molecules were attached through thiol-AuNP bonds to produce the final cit-AuNPs/MPA/Si-NH₂ QDs/Con A smart nanoparticles. The synthesized novel cit-AuNPs/MPA/Si-NH₂ QDs/Con A nanoparticles were utilized for the bioimaging of glycan-overexpressed breast cancer cells. Fluorescence microscopy and flow cytometry results revealed that the cit-AuNPs/MPA/Si-NH₂ QDs/Con A NPs can be efficiently taken up by cancer cells, with differentiating ability between overexpressed cancer cells and low-expressed normal cells. The cellular viability of the cit-AuNPs/MPA/Si-NH₂ QDs/Con A NPs was tested by the MTT test, proving their biocompatible nature at the 200 μg mL^-1 level. In conclusion, the fabricated cit-AuNPs/MPA/Si-NH₂ QDs/Con A NPs could be utilized for the bioimaging of MCF-7 cancer cells even in the clinical setting after proper in vivo validation.

Applications of Advanced Materials for Non-Enzymatic Glucose Monitoring: From Invasive to the Wearable Device

Diabetes mellitus (DM) is a global health problem leading to many complications and disabilities in life adjusting activities and even dead. Monitoring glucose levels is a key factor in diagnosis and management of DM. Conventional glucose sensors consisted of immobilized enzymes, are so susceptible to environmental conditions. In this way, nonenzymatic biosensors have attracted extensive attentions in many clinical diagnostics applications. To date, the finger pricking test is a common enzyme-based glucometer that is an invasive and inconvenient and may lead to infections in the injection sites. So, working on the possibility of cutaneous or subcutaneous insertion of devices as a noninvasive or minimally-invasive systems for continuous glucose controlling approaches through human biofluids (blood, perspiration, tears, saliva, etc.) have stimulated growing interest. This review summarizes recent nonenzymatic and noninvasive biofluids glucose monitoring systems which are highly resilience and stretchable to continuously adapt to body movements during common physical activity. Sensors are based on their constituent materials including carbon-based, metal nanoparticles, polymer, and hydrogel systems are classified for electrochemical, and optical glucose detection. Finally, we address the drawbacks and challenges of enzyme-free sensors which are aroused sustaining research passion to be used in point-of-care medical diagnostics applications.

Carbon-based aerogels for biomedical sensing: Advances toward designing the ideal sensor

Carbon based aerogels are special solid-state materials comprised of interconnected networks of 3D nanostructures with high amount of air-filled nanoporous. They expand the structural properties along with physicochemical characteristics of nanoscale construction blocks to macroscale, and incorporate distinctive attributes of aerogels, like large surface area, high porosity, and low density, with particular features of the different constituents. These features impart aerogels with rapid response signal, high selectivity, and ultra-sensitivity for sensing diverse targets in biomedical media. This has prompted researchers to develop a variety of aerogel-based sensors with encouraging achievements. Hence, this work outlines sensing applications of aerogel-based sensors with a comprehensive overview on the carbon aerogel hybrid materials and their analytical performances. Authors tried to list advantages and limitations of the developed approach and introduced more potent research for possible devices designing. We also point out some challenges and future perspectives related to the improvement of high-efficiency aerogel-based sensors.

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.

Sensitive monitoring of doxorubicin in plasma of patients, MDA-MB-231 and 4T1 cell lysates using electroanalysis method

In the present work, an innovative electrochemical sensor was fabricated based on poly toluidine blue modified glassy carbon electrode (PTB-GCE). So, PTB-GCE was used for the detection and determination of doxorubicin hydrochloride (DOX) in cell lysate, and whole human plasma samples. PTB could enhance the rate of electrochemical reaction for the electro oxidation and detection of DOX in real samples. Cyclic voltammetry (CV) technique was used for the electro polymerization of toluidine blue on the surface of GCE with the applied potential ranging from -0.6 to 0.2 V. The sensor construction steps were approved by field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX) and electrochemical methods. Also, CV results indicated that the DOX is oxidized via two electrons and two protons process at the optimum pH of 6.5 using PTB modified GCE. Under optimized conditions, differential pulse voltammetry (DPV) technique response exhibited linear relationship between the oxidative peak current and concentration of DOX in the range of 17 nM - 8.6 μM with low limit of quantification (LLOQ) of 17 nM for untreated and treated human plasma samples. Also, determination of DOX in MDA-MB-231 and 4T1cell lysates were performed based on its direct electrochemical oxidation on PTB-GCE. Finally, analytical validation of DOX in human bio-fluids using FDA guideline were done successfully. Results suggested that the proposed electrochemical sensor can be used to the sensitive and selective determination of DOX in biological samples. The interaction results of DOX with cancer cells indicate the developed probe can easily detect candidate drug in cancer cells with high accuracy. To the best of our knowledge this is the first report of the determination of DOX based on the direct electrochemical oxidation on PTB-GCE and determination in MDA-MB-231 and 4T1 cell lysates. It is anticipated that this research open new horizons on the design of new class of electrochemical sensors for determination drugs, and therapeutic drug monitoring (TDM) in human bio-fluids.