Small Warriors of Nature: Novel Red Emissive Chlorophyllin Carbon Dots Harnessing Fenton-Fueled Ferroptosis for In Vitro and In Vivo Cancer Treatment.

The appeal of carbon dots (CDs) has grown recently, due to their established biocompatibility, adjustable photoluminescence properties, and excellent water solubility. For the first time in the literature, copper chlorophyllin-based carbon dots (Chl-D CDs) are successfully synthesized. Chl-D CDs exhibit unique spectroscopic traits and are found to induce a Fenton-like reaction, augmenting photodynamic therapy (PDT) efficacies via ferroptotic and apoptotic pathways. To bolster the therapeutic impact of Chl-D CDs, a widely used cancer drug, temozolomide, is linked to their surface, yielding a synergistic effect with PDT and chemotherapy. Chl-D CDs' biocompatibility in immune cells and in vivo models showed great clinical potential.Proteomic analysis was conducted to understand Chl-D CDs' underlying cancer treatment mechanism. The study underscores the role of reactive oxygen species formation and pointed toward various oxidative stress modulators like aldolase A (ALDOA), aldolase C (ALDOC), aldehyde dehydrogenase 1B1 (ALDH1B1), transaldolase 1 (TALDO1), and transketolase (TKT), offering a deeper understanding of the Chl-D CDs' anticancer activity. Notably, the Chl-D CDs' capacity to trigger a Fenton-like reaction leads to enhanced PDT efficiencies through ferroptotic and apoptotic pathways. Hence, it is firmly believed that the inherent attributes of Chl-CDs can lead to a secure and efficient combined cancer therapy.

An innovative method for the detection of alpha synuclein, a potential biomarker of Parkinson's disease: quartz tuning fork-based mass sensitive immunosensor design.

An innovative biosensing fabrication strategy has been demonstrated for the first time using a quartz tuning fork (QTF) to develop a practical immunosensor for sensitive, selective and practical analysis of alpha synuclein protein (SYN alpha), a potential biomarker of Parkinson's disease. Functionalization of gold-coated QTFs was carried out in 2 steps by forming a self-assembled monolayer with 4-aminothiophenol (4-ATP) and conjugation of gold nanoparticles (AuNPs). The selective determination range for SYN alpha of the developed biosensor system is 1-500 ng mL-1 in accordance with the resonance frequency shifts associated with a limit of detection of 0.098 ng mL-1. The changes in surface morphology and elemental composition were evaluated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDX). The remarkable point of the study is that this QTF based mass sensitive biosensor system can capture the SYN alpha target protein in cerebrospinal fluid (CSF) samples with recoveries ranging from 92% to 104%.

A novel SLC35D1 variant causing milder phenotype of Schneckenbecken dysplasia in a large pedigree.

SLC35D1 gene encodes UDP-glucuronic acid/UDP-n-acetylgalactosamine dual transporter protein and transports organic or inorganic molecules across cellular membranes. SLC35D1 gene pathogenic variants causes Schneckenbecken dysplasia (SHNKND) which is a rare lethal autosomal recessive disorder characterized by the snail-like pelvis, flattening of vertebral bodies, short and broad long bones with a dumbbell-like appearance, thoracic hypoplasia. Only six cases with homozygous SLC35D1 variants have been reported to date, and all of these cases were lost in the perinatal period. Here we report different family members with a novel SLC35D1 variant who presented a milder phenotype of SHNKND. The affected patients have common clinical features such as short stature, mild mesomelia, shortening of the lower extremity, genu valgum, and narrow thorax. Exome sequencing of the proband revealed a homozygous missense variant of SLC35D1 gene, c.401 T > C (p. Met134Thr). The affected siblings, their two cousins, and their paternal uncle with a similar phenotype were also homozygous for the variant. This is the first case report of a family with a novel likely pathogenic variant (p. Met134Thr) and mild phenotypic features. It has the largest family with different ages of patients (ages ranged 4-31 years old) reported to date. The present report supports the evidence that the p. Met134Thr variant is responsible for a milder phenotype than previously reported cases with SLC35D1 pathogenic variants.

Graphene Oxide Nanosheets Interact and Interfere with SARS-CoV-2 Surface Proteins and Cell Receptors to Inhibit Infectivity.

Nanotechnology can offer a number of options against coronavirus disease 2019 (COVID-19) acting both extracellularly and intracellularly to the host cells. Here, the aim is to explore graphene oxide (GO), the most studied 2D nanomaterial in biomedical applications, as a nanoscale platform for interaction with SARS-CoV-2. Molecular docking analyses of GO sheets on interaction with three different structures: SARS-CoV-2 viral spike (open state - 6VYB or closed state - 6VXX), ACE2 (1R42), and the ACE2-bound spike complex (6M0J) are performed. GO shows high affinity for the surface of all three structures (6M0J, 6VYB and 6VXX). When binding affinities and involved bonding types are compared, GO interacts more strongly with the spike or ACE2, compared to 6M0J. Infection experiments using infectious viral particles from four different clades as classified by Global Initiative on Sharing all Influenza Data (GISAID), are performed for validation purposes. Thin, biological-grade GO nanoscale (few hundred nanometers in lateral dimension) sheets are able to significantly reduce copies for three different viral clades. This data has demonstrated that GO sheets have the capacity to interact with SARS-CoV-2 surface components and disrupt infectivity even in the presence of any mutations on the viral spike. GO nanosheets are proposed to be further explored as a nanoscale platform for development of antiviral strategies against COVID-19.

House dust mite-derived allergens effect on matrix metalloproteases in airway epithelial cells.

Aim of the Study: Many allergens have protease activities. Although the immunomodulatory effects of these antigens are well known, the effects attributed to their protease activities are not thoroughly investigated. We set out to determine the effects of house dust mite (HDM) allergens with varying protease activities on bronchial epithelial cell functions. Materials and methods: BEAS-2B cells were maintained in ALI-culture and stimulated with Der p1 (cysteine protease), Der p6 (serine protease), and Der p2 (non-protease) with and without specific protease inhibitors or heat denaturation. Cell viability and epithelial permeability were measured with MTT and paracellular flux assay, respectively. The effect of heat denaturation on allergen structure was examined using in silico models. Matrix metalloproteinases (MMPs) were investigated at the transcription (qPCR), protein (ELISA), and functional (zymography) levels. Results: Epithelial permeability increased only after Der p6 but not after Der p1 or Der p2 stimulation. Der p2 increased both MMP-2 and MMP-9 expression, while Der p1 increased only MMP-9 expression. The heat-denatured form of Der p1 unexpectedly increased MMP-9 gene expression, which, through the use of in silico models, was attributed to its ability to change receptor connections by the formation of new electrostatic and hydrogen bonds. IL-8 and GM-CSF production were increased after Der p1 and Der p2 but decreased after Der p6 stimulation. IL-6 decreased after Der p1 but increased following stimulation with Der p6 and heat-denatured Der p2. Conclusion: Allergens in house dust mites are capable of inducing various changes in the epithelial cell functions by virtue of their protease activities.

Ribavirin shows antiviral activity against SARS-CoV-2 and downregulates the activity of TMPRSS2 and the expression of ACE2 in vitro.

Ribavirin is a guanosine analog with broad-spectrum antiviral activity against RNA viruses. Based on this, we aimed to show the anti-SARS-CoV-2 activity of this drug molecule via in vitro, in silico, and molecular techniques. Ribavirin showed antiviral activity in Vero E6 cells following SARS-CoV-2 infection, whereas the drug itself did not show any toxic effect over the concentration range tested. In silico analysis suggested that ribavirin has a broad-spectrum impact on SARS-CoV-2, acting at different viral proteins. According to the detailed molecular techniques, ribavirin was shown to decrease the expression of TMPRSS2 at both mRNA and protein levels 48 h after treatment. The suppressive effect of ribavirin in ACE2 protein expression was shown to be dependent on cell types. Finally, proteolytic activity assays showed that ribavirin also showed an inhibitory effect on the TMPRSS2 enzyme. Based on these results, we hypothesized that ribavirin may inhibit the expression of TMPRSS2 by modulating the formation of inhibitory G-quadruplex structures at the TMPRSS2 promoter. As a conclusion, ribavirin is a potential antiviral drug for the treatment against SARS-CoV-2, and it interferes with the effects of TMPRSS2 and ACE2 expression.

Photocatalytically Active Graphitic Carbon Nitride as an Effective and Safe 2D Material for In Vitro and In Vivo Photodynamic Therapy.

Thanks to its photocatalytic property, graphitic carbon nitride (g-C3 N4 ) is a promising candidate in various applications including nanomedicine. However, studies focusing on the suitability of g-C3 N4 for cancer therapy are very limited and possible underlying molecular mechanisms are unknown. Here, it is demonstrated that photoexcitation of g-C3 N4 can be used effectively in photodynamic therapy, without using any other carrier or additional photosensitizer. Upon light exposure, g-C3 N4 treatment kills cancer cells, without the need of any other nanosystem or chemotherapeutic drug. The material is efficiently taken up by tumor cells in vitro. The transcriptome and proteome of g-C3 N4 and light treated cells show activation in pathways related to both oxidative stress, cell death, and apoptosis which strongly suggests that only when combined with light exposure, g-C3 N4 is able to kill cancer cells. Systemic administration of the mesoporous form results in elimination from urinary bladder without any systemic toxicity. Administration of the material significantly decreases tumor volume when combined with local light treatment. This study paves the way for the future use of not only g-C3 N4 but also other 2D nanomaterials in cancer therapy.

Identification of novel Nrf2/Keap1 pathway mutations in pediatric acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is a malignancy of lymphoid progenitor cells, characterized by a wide range of biological and clinical heterogeneity. Oxidative stress is a common problem observed in carcinogenesis and it is involved in developing treatment resistance. Nuclear Factor Erythroid-2-Like 2 (Nrf2) transcription factor is the main regulator of antioxidant responses. The levels of reactive oxygen species (ROS) are tightly controlled and regulated by Nrf2 and its suppressor protein Kelch-like ECH-associated protein 1 (Keap1). Recently, many studies have shown that most of the genes in the Nrf2/Keap1/nuclear factor kappa-B (NF-κB)/phosphotyrosine-independent ligand for the Lck SH2 domain Of 62 KDa (p62) pathway show abnormally high mutational variations in cancer. However, variations in the Nrf2/Keap1/NF-κB1/p62 pathway in pediatric ALL have not been thoroughly investigated, yet. Thirty children, who were diagnosed with pediatirc ALL were included in the study. The Nrf2/Keap1/NF-κB1/p62 pathway variants were analyzed by DNA sequencing analysis. The PolyPhen-2 program was used for identifying pathogenic mutations. Our study examined the molecular dynamics (MD) perspectives of the effect of A159T and E121K mutations on protein stability for the first time in the literature by using the GROMACS45 software package utilizing the OPSLAA force field. Of the detected 17 nucleotide changes, 6 were novel. The study predicted the potential pathological effect of two mutations p. A159T and p.E121K in the Keap1 gene. The MD perspectives revealed that the E121K mutant's observed structural behavior accounted for the key role of His-129 and E121K, where E121K exhibited much higher drift compared to His-129. For a future perspective, it would be meaningful to study the protein-small molecule interactions of the Keap1 protein to elaborate on the drug effects in patients carrying these mutations.

Nanomaterial-assisted molecularly imprinted polymer strategies for highly sensitive and selective determination of cefdinir and its validation using computational approach.

In this study, the first nanomaterial-supported molecularly imprinted polymer (MIP)-based electrochemical approach was proposed to achieve the successful detection of cefdinir (CFD). Here, p-amino benzoic acid (p-ABA) was used as the monomer and the photopolymerization method was chosen to form MIP on a glassy carbon electrode (GCE). ZnO nanoparticles (ZnO NPs) were added to the MIP sensor to increase sensitivity and create high porosity. Through the use of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), characterization investigations confirmed the alterations at each stage of the MIP production process. Electrochemical (cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS)) and scanning electron microscopy (SEM) methods were used for study the characterization studies of the MIP-based nanocomposite sensor. The measurement of MIP parameters, such as the addition of nanoparticles, the removal procedure, the rebinding period, the monomer ratio, etc., was done using the differential pulse voltammetry (DPV). The findings showed that when ZnO NPs were added, the signal was three times higher than when MIPs were used alone. Under the optimized conditions, CFD/4-ABA@ZnONPs/MIP/GCE showed a linear response in the concentration range between 7.5 pM and 100 pM with LOD and LOQ values of 2.06 pM and 6.86 pM, respectively. Anions, cations, and substances including uric acid, ascorbic acid, paracetamol, and dopamine were all used in the selectivity test. In addition, the imprinting factor (IF) study was carried out using compounds such as cefuroxime, cefazolin, cefixime, ceftazidime, and ceftriaxone, which have structural similarities with CFD, as well as impurities such as thiazolylacetyl glycine oxime (IMP-A), thiazolylacetyl glycine oxime acetal (IMP-B), and cefdinir lactone (IMP-E). The results showed that the proposed sensor was selective for CFD, as evidenced by the relative IF values of these impurities. The recovery studies of CFD were successfully applied to tablet dosage form samples, and the developed sensor demonstrated significant sensitivity and selectivity for rapid detection of CFD in tablet dosage form.

Ultrasensitive electrochemical immunosensor system for determination of autologous SOX2 antibody.

Lung cancer is mainly seen as the cancer type in the world. Lung cancer causes the death of many people. It is classified as large-cell neuroendocrine carcinoma (LCNEC), small-cell lung cancer (SCLC), and adenocarcinoma by the World Health Organization (WHO) in 2015. Small cell lung cancer (SCLC) is a highly aggressive type of cancer, accounting for approximately 20% of all cases. By performing the serological analysis of expression cDNA libraries (SEREX), the humoral immune response of SCLC patients is determined. SEREX of SCLC cell lines using pooled sera of SCLC patients led to the isolation of SOX2 genes. The between SOX2 antigen expression intensity and autologous antibody presence has a significant correlation because SOX2 is the main antigen eliciting anti-SOX responses. Electrochemical biosensors take much attention because of their simplicity, selectivity, and sensitivity in clinical analysis. Antibody-based surface recognizes antibody-specific antigens. This work aims to fabricate an immunosensor for determining autologous SOX2 antibodies using a multi-walled carbon nanotube-modified screen-printed electrode (DRP-MWCNT). All immobilization processes were evaluated with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The critical parameters were optimized, such as EDC/NHS concentration and time, SOX2 protein concentration and incubation time, BSA ratio, BSA blocking time, and anti-SOX2 antibody incubation time. The developed immunosensor, under optimal conditions, shows a linear response of autologous SOX2 antibody between 0.005 ng.mL-1 and 0.1 ng.mL-1. The limit of detection and quantification were 0.001 and 0.004 ng.mL-1, respectively. The electrode morphologies were examined with a scanning electron microscope (SEM). Lastly, the developed immunosensor was applied to a synthetic serum sample, and the linear range was compared with enzyme-linked immunosorbent assay (ELISA).

The Evaluation of Clinical Applications for the Detection of the Alzheimer's Disease Biomarker GFAP.

One of the most prevalent neurodegenerative diseases is Alzheimer's disease (AD). The hallmarks of AD include the accumulation of amyloid plaques and neurofibrillary tangles, which cause related secondary diseases, progressive neurodegeneration, and ultimately death. The most prevalent cell type in the human central nervous system, astrocytes, are crucial for controlling neuronal function. Glial fibrillary acidic protein (GFAP) is released from tissue into the bloodstream due to astrocyte breakdown in neurological diseases. Increased levels of GFAP in the serum can function as blood markers and be an effective prognostic indicator to help diagnose neurological conditions early on, from stroke to neurodegenerative diseases. The human central nervous system (CNS) is greatly affected by diseases associated with blood GFAP levels. These include multiple sclerosis, intracerebral hemorrhage, glioblastoma multiforme, traumatic brain injuries, and neuromyelitis optica. GFAP demonstrates a strong diagnostic capacity for projecting outcomes following an injury. Furthermore, the increased ability to identify GFAP protein fragments helps facilitate treatment, as it allows continuous screening of CNS injuries and early identification of potential recurrences. GFAP has recently gained attention due to data showing that the plasma biomarker is effective in identifying AD pathology. AD accounts for 60-70% of the approximately 50 million people with dementia worldwide. It is critical to develop molecular markers for AD, whose number is expected to increase to about 3 times and affect humans by 2050, and to investigate possible targets to confirm their effectiveness in the early diagnosis of AD. In addition, most diagnostic methods currently used are image-based and do not detect early disease, i.e. before symptoms appear; thus, treatment options and outcomes are limited. Therefore, recently developed methods such as point-of-care (POC), on-site applications, and enzyme-linked immunosorbent assay-polymerase chain reaction (ELISA-PCR) that provide both faster and more accurate results are gaining importance. This systematic review summarizes published studies with different approaches such as immunosensor, lateral flow, POC, ELISA-PCR, and molecularly imprinted polymer using GFAP, a potential blood biomarker to detect neurological disorders. Here, we also provide an overview of current approaches, analysis methods, and different future detection strategies for GFAP, the most popular biosensing field.

Effect of Disulfide Bonds on the Thermal Stability of Pediocin: In-silico Screening Using Molecular Dynamics Simulation.

The thermal stability properties of pediocin at 310, 313, 323, 333, 343, and 348 K (37, 40, 50, 60, 70, and 75°C, respectively) are reported in this study. A theoretical approach, such as the molecular dynamics method, was used to analyze the structure. Molecular dynamics simulation confirms the stability of molecules with Cys. Furthermore, this study reveals that Cys residues play an essential role in structure stability at high temperatures. To understand the structural basis for the stability of pediocin, a detailed in-silico analysis using molecular dynamics simulations to explore the thermal stability profiles of the compounds was conducted. This study shows that thermal effects fundamentally alter the functionally crucial secondary structure of pediocin. However, as previously reported, pediocin's activity was strictly conserved due to the disulfide bond between Cys residues. These findings reveal, for the first time, the dominant factor behind the thermodynamic stability of pediocin.

Electrochemical detection of lactate produced by foodborne presumptive lactic acid bacteria.

The detection of lactate is an important indicator of the freshness, stability, and storage stability of products as well as the degree of fermentation in the food industry. In addition, it can be used as a diagnostic tool in patients' healthcare since it is known that the lactate level in blood increases in some pathological conditions. Thus, the determination of lactate level plays an important role in not only the food industry but also in health fields. As a result, biosensor technologies, which are quick, cheap, and easy to use, have become important for lactate detection. In the current study, amperometric lactate biosensors based on lactate oxidase immobilization (with Nafion 5% wt) were designed and the limit of detection, linear range, and sensitivity values were determined to be 31 µM, 50-350 µM, and 0.04 µA µM-1 cm-2, respectively. Then, it was used for the measurement of lactic acid that produced by six different and morphologically identified presumptive lactic acid bacteria (LAB) which are isolated from different naturally fermented cheese samples. The biosensors were then used to successfully perform lactate measurements within 3 min for each sample, even though a few of them were out of the limit of detection. Thus, electrochemical biosensors should be used as an alternative and quick solutions for the measurement of lactate metabolites rather than the traditional methods which require long working hours. This is the first study to use a biosensor to measure lactate produced by foodborne LAB in a real sample.

Low Dose of Ti3 C2 MXene Quantum Dots Mitigate SARS-CoV-2 Infection.

MXene QDs (MQDs) have been effectively used in several fields of biomedical research. Considering the role of hyperactivation of immune system in infectious diseases, especially in COVID-19, MQDs stand as a potential candidate as a nanotherapeutic against viral infections. However, the efficacy of MQDs against SARS-CoV-2 infection has not been tested yet. In this study, Ti3 C2 MQDs are synthesized and their potential in mitigating SARS-CoV-2 infection is investigated.  Physicochemical characterization suggests that MQDs are enriched with abundance of bioactive functional groups such as oxygen, hydrogen, fluorine, and chlorine groups as well as surface titanium oxides. The efficacy of MQDs is tested in VeroE6 cells infected with SARS-CoV-2. These data demonstrate that the treatment with MQDs is able to mitigate multiplication of virus particles, only at very low doses such as 0,15 µg mL-1 . Furthermore, to understand the mechanisms of MQD-mediated anti-COVID properties, global proteomics analysis are performed and determined differentially expressed proteins between MQD-treated and untreated cells. Data reveal that MQDs interfere with the viral life cycle through different mechanisms including the Ca2 + signaling pathway, IFN-α response, virus internalization, replication, and translation. These findings suggest that MQDs can be employed to develop future immunoengineering-based nanotherapeutics strategies against SARS-CoV-2 and other viral infections.

Synergized photothermal therapy and magnetic field induced hyperthermia via bismuthene for lung cancer combinatorial treatment.

Thanks to its intrinsic properties, two-dimensional (2D) bismuth (bismuthene) can serve as a multimodal nanotherapeutic agent for lung cancer acting through multiple mechanisms, including photothermal therapy (PTT), magnetic field-induced hyperthermia (MH), immunogenic cell death (ICD), and ferroptosis. To investigate this possibility, we synthesized bismuthene from the exfoliation of 3D layered bismuth, prepared through a facile method that we developed involving surfactant-assisted chemical reduction, with a specific focus on improving its magnetic properties. The bismuthene nanosheets showed high in vitro and in vivo anti-cancer activity after simultaneous light and magnetic field exposure in lung adenocarcinoma cells. Only when light and magnetic field are applied together, we can achieve the highest anti-cancer activity compared to the single treatment groups. We have further shown that ICD-dependent mechanisms were involved during this combinatorial treatment strategy. Beyond ICD, bismuthene-based PTT and MH also resulted in an increase in ferroptosis mechanisms both in vitro and in vivo, in addition to apoptotic pathways. Finally, hemolysis in human whole blood and a wide variety of assays in human peripheral blood mononuclear cells indicated that the bismuthene nanosheets were biocompatible and did not alter immune function. These results showed that bismuthene has the potential to serve as a biocompatible platform that can arm multiple therapeutic approaches against lung cancer.

Emerging 2D materials for antimicrobial applications in the pre- and post-pandemic era.

Infectious diseases caused by viral or bacterial pathogens are one of the most serious threats to humanity. Moreover, they may lead to pandemics, as we have witnessed severely with the coronavirus disease 2019 (COVID-19). Nanotechnology, including technological developments of nano-sized materials, has brought great opportunities to control the spreading of such diseases. In the family of nano-sized materials, two-dimensional (2D) materials with intrinsic physicochemical properties can efficiently favor antimicrobial activity and maintain a safer environment to protect people against pathogens. For this purpose, they can be used alone or combined for the disinfection process of microbes, antiviral or antibacterial surface coatings, air filtering of medical equipment like face masks, or antimicrobial drug delivery systems. At the same time, they are promising candidates to deal with the issues of conventional antimicrobial approaches such as low efficacy and high cost. This review covers the antiviral or antibacterial activities of 2D materials and highlights their current and possible future applications. Considering their intrinsic properties, 2D materials will become part of the leading antimicrobial technologies for combating future pandemics anytime soon.

Ultrasensitive Determination of Glial-Fibrillary-Acidic-Protein (GFAP) in Human Serum-Matrix with a Label-Free Impedimetric Immunosensor.

In this work, immobilizing anti-GFAP antibodies via covalent attachment onto L-cysteine/gold nanoparticles that were modified with screen-printed carbon electrodes (Anti-GFAP/L-cys/AuNps/SPCE) resulted in the development of a sensitive label-free impedance immunosensor for the detection of Glial Fibrillary Acidic Protein (GFAP). The immunosensor's stepwise construction was studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). L-cysteine was chosen as the linker between GFAP antibodies and Au NPs/SPCE because it enables the guided and stable immobilization of GFAP antibodies, thus resulting in increased immunosensor sensitivity. As a redox probe, 5 mM of [Fe(CN)6]3-/4- was used to measure the electron-transfer resistance (Ret), which was raised by the binding of antigens to the immobilized anti-GFAP on the surface of the modified electrode. A linear correlation between Rct and GFAP concentration was achieved under optimum conditions in the range of 1.0-1000.0 pg/mL, with an extraordinarily low detection limit of 51.0 fg/mL. The suggested immunosensor was successfully used to detect the presence of GFAP in human blood serum samples, yielding good findings. As a result, the proposed platform may be utilized to monitor central nervous system injuries.

Novel Sensor Approaches of Aflatoxins Determination in Food and Beverage Samples.

The rapid quantification of toxins in food and beverage products has become a significant issue in overcoming and preventing many life-threatening diseases. Aflatoxin-contaminated food is one of the reasons for primary liver cancer and induces some tumors and cancer types. Advancements in biosensors technology have brought out different analysis methods. Therefore, the sensing performance has been improved for agricultural and beverage industries or food control processes. Nanomaterials are widely used for the enhancement of sensing performance. The enzymes, molecularly imprinted polymers (MIP), antibodies, and aptamers can be used as biorecognition elements. The transducer part of the biosensor can be selected, such as optical, electrochemical, and mass-based. This review explains the classification of major types of aflatoxins, the importance of nanomaterials, electrochemical, optical biosensors, and QCM and their applications for the determination of aflatoxins.

Human hair rich in pyridinic nitrogen-base DNA biosensor for direct electrochemical monitoring of palbociclib-DNA interaction.

Carbon material derived from the waste-based biomass human hair (H), which is naturally rich in pyridinic nitrogen, provides a significant benefit in biosensor applications with its dominant conductivity character. The carbon material was synthesized from human hair waste by the hydrothermal carbonization (HTC) method, which is a promising green synthesis. A morphological characterization of the carbon materials was performed. In this study, H and amine-functionalized multi-walled carbon nanotubes (NH2-MWCNT) were combined for the first time as a modifier, which enhanced the glassy carbon electrode (GCE) surface area for deoxyribonucleic acid (DNA) biosensor studies. Palbociclib (PLB) is clinically used in the treatment of breast cancer. The novel electrochemical nanobiosensor was used to investigate the dsDNA-PLB interaction to evaluate the possibility that PLB causes conformational changes in DNA structure and/or oxidative damage. The interaction was conducted based on the voltammetric signals of deoxyguanosine (dGuo) and deoxyadenosine (dAdo) by differential pulse voltammetry (DPV) on a bare and H + NH2-MWCNT modified GCE. The proposed analytical method was applied to a pharmaceutical dosage form with a satisfactory recovery of 98.25 %. The nanobiosensor was tested in the presence of some interfering agents. The binding mechanism of dsDNA-PLB was also evaluated by spectroscopic and theoretical calculations.

Assisting dementia diagnosis through the electrochemical immunosensing of glial fibrillary acidic protein.

Glial fibrillary acidic protein (GFAP) is a member of the intermediate filament family of proteins with increased levels in serum and cerebrospinal fluid of patients with Alzheimer disease (AD) and other neurodegenerative diseases (NDs), such as vascular dementia (VD). This work describes the first magnetic microbeads (MBs)-based electrochemical immunoplatform for GFAP determination. The platform design comprises a sandwich immunoassay implemented on the MBs surface and amperometric transduction at single-use screen-printed carbon electrodes (SPCEs). Micro-sized carboxylic acid magnetic particles (COOH-MBs) were modified with a specific capture antibody (CAb) to selectively link the target protein, which was sandwiched with a biotinylated detector antibody (btn-DAb) further conjugated with a streptavidin-peroxidase (Strep-HRP) conjugate. Amperometric transduction was performed at SPCEs upon capturing the magnetic bioconjugates on their surface and through the hydrogen peroxide/hydroquinone (H2O2/HQ) system. The immunoplatform achieved a limit of detection of 67 pg mL-1 for the amperometric detection of standards and selectivity compatible with clinical applicability to assist in minimally invasive NDs diagnosis and prognosis. The MBs-based immunoplatform was applied with good results to determine the endogenous content of GFAP in protein brain extracts without matrix effect and using just 6.25 ng of sample per determination. Furthermore, the developed methodology was capable of differentiating between healthy subjects and patients diagnosed with VD and AD in only 2 h, providing accurate results in line with those obtained by an ELISA kit that used the same immunoreagents.