Design and application of histidine-functionalized ZnCr-LDH nanozyme for promoting bacteria-infected wound healing.

Excessive use of antibiotics can lead to an increase in antibiotic-resistant bacteria, which makes it a serious health threat. Therefore, developing new materials with antibacterial activity, such as nanozymes, has gained considerable attention. Reactive oxygen species (ROS) produced by nanozymes have rapid and effective antibacterial efficacy. Here, histidine (His) modified ZnCr layered double hydroxide (LDH) was synthesized inspired by the natural enzyme, and the enzyme-like activity of His/ZnCr-LDH was tested using a colorimetric method. Then, we developed an acid-enhanced antibacterial method based on the high peroxidase-like activity of His/ZnCr-LDH, and its ROS-generating capability in the presence of glucose oxidase (GOx) and glucose (Glu) as a source of hydrogen peroxide (H2O2). Gluconic acid (GA), the main product of the GOx reaction, provides an acidic environment and promotes ROS generation. The mentioned strategy shows high antibacterial activity at a low minimum inhibitory concentration (MIC) which represents the potential of His/ZnCr-LDH for effective bacterial elimination (3.5 µg mL-1 for S. aureus and 6 µg mL-1 for E. coli). In addition, animal experiments illustrated that the His/ZnCr-LDH can successfully boost the curing of infected wounds. The outcomes indicate that amino acid modified LDHs offer a new strategy for effective bacterial removal in different medical applications.

Proficient sonophotocatalytic degradation of organic pollutants using Co3O4/TiO2 nanocomposite immobilized on zeolite: Optimization, and artificial neural network modeling.

The health of all living organisms is greatly influenced by the quality of the water. Therefore, developing cost-effective, eco-friendly, and easily accessible methods is desperately needed to meet the high global demand for clean water. Recently, nanozyme-based dye degradation methods have been promising for the remediation of water pollution. In this work, peroxidase-mimic Co3O4/TiO2 nanocomposite was synthesized and characterized for its size, morphology, and crystalline structure. Colorimetric assay results showed that the peroxidase-like activity of the Co3O4/TiO2 nanocomposite was considerably enhanced compared to the pure Co3O4 NPs and TiO2 NPs. Besides excellent enzyme-mimic activity, the higher sonophotocatalytic dye degradation capability of the nanocomposite after immobilization on zeolite (Co3O4/TiO2@Ze) was also demonstrated. Under optimal conditions (pH = 5.0, 25 °C), 0.1 g/L of catalyst was able to degrade 100 % of methylene blue (MB) with 600 µM in the presence of 30 µM H2O2 within 12 min. GC/MS analysis and toxicity studies revealed less toxic metabolite production after treatment of MB with sonophotocatalytic Co3O4/TiO2@Ze. Modeling of MB degradation using artificial neural networks (ANN) with a 5:6:1 topology was successfully performed, and the results confirmed the fitness of theoretical and experimental outputs according to the calculated correlation coefficient values. The prepared nanocomposite could thus be used as a promising and highly effective catalyst for the removal of organic dyes from polluted water.

Detection of pioglitazone based on dual-emission ratiometric fluorescence probe consisting of ZIF8 and to L-ASC-AuNP/DA nanoparticles.

A simple and sensitive dual-emission ratiometric fluorescent probe was developed using zeolitic imidazolate framework 8 (ZIF8) and L-ascorbic acid Au-doped dopamine nanoparticles (ZIF8/L-ASC-AuNP/DA NP) for the determination of pioglitazone (Pio), an oral hypoglycemic agent and insulin sensitizer, in real samples. The prepared system was based on the Pio-enhanced dual-emission intensity of ZIF8/L-ASC-AuNP/DA NP. The potential impact of various parameters on the system's emission intensity was tested. According to the findings, there is a strong linear correlation between the system's turn-on fluorescence intensity and Pio concentrations in the range 0.3 nM to 30.0 µM. The obtained value for the limit of detection (LOD) was 0.14 nM. In addition, the intra- and inter-day accuracy of the nanoprobe was studied and the findings revealed satisfactory precision and accuracy of the system. The short-term and freeze-thaw stability of Pio in plasma samples was evaluated and the results indicated the high stability of the developed nanoprobe under the test conditions. Pio was accurately detected in human plasma samples under ideal conditions with analytical recoveries in the range 86.0 - 109.3%. The results showed that the devised probe may be employed as an easy, sensitive, and precise approach for detecting Pio in real samples.

Bimetallic metal-organic framework as an efficient sorbent for the extraction of tacrolimus and cyclosporine from plasma before HPLC-MS/MS analysis.

This study investigated the application of pores-size protocols into metal-organic frameworks that can lead to improved adsorption capacity of sorbents. A selective, fast, and sensitive analytical procedure based on dispersive solid phase extraction using a bimetallic metal organic framework named ZrZnMOF coupled with high-performance liquid chromatography-tandem mass spectrometry was established for the simultaneous quantification of tacrolimus and cyclosporine in plasma. The effects of several parameters, such as the dosage of sorbent, separation and elution times, volume and type of elution solvent, were investigated. Under optimal conditions, high extraction recovery (70 and 89 for tacrolimus and cyclosporine, respectively), low limits of detection (0.15 and 0.31 µg L-1 for tacrolimus and cyclosporine, respectively) and quantification (1.0 and 0.51 µg L-1 for tacrolimus and cyclosporine, respectively) wide linearity (1.0-1000 and 0.51-500 µg L-1 for tacrolimus and cyclosporine, respectively), and acceptable repeatability (n = 5, relative standard deviation less than 5.6 %) were attained. The validated method was successfully applied to quantify tacrolimus and cyclosporine A in plasma samples obtained from different volunteers.

Insight into the effect of ibuprofen on the permeability of the membrane: a molecular dynamic simulation study.

Studying interactions between drugs and cell membranes is of great interest to designing novel drugs, optimizing drug delivery, and discerning drug mechanism action. In this study, we investigated the physical properties of the bilayer membrane model of POPC upon interaction with ibuprofen (IBU) using molecular dynamics simulations. The area per lipid (APL) was calculated to describe the effect of ibuprofen on the packing properties of the lipid bilayer. The APL was 0.58 nm2 and 0.63 nm2 for the membrane in low and high IBU respectively, and 0.57 nm2 for the membrane without IBU. Our finding showed that the mean square deviation (MSD) increased with increased ibuprofen content. In addition, the order parameter for the hydrocarbon chain of lipids increased with increased ibuprofen content. There was an increment in the transfer free energy after the head group region while it was maximum in the hydrophobic core for hydrogen peroxide (H2O2) (∼6.2 kcal.mol-1) and H2O (∼3.4 kcal.mol-1) which then decreased to respective values of (∼4.6 kcal.mol-1), and (∼2.3 kcal.mol-1) at the center of the bilayer in the presence of IBU. It seems that in the presence of ibuprofen, the free energy profile of the permeability of water and H2O2 significantly decreased. These findings show that ibuprofen significantly influences the physical properties of the bilayer by decreasing the packing and intermolecular interaction in the hydrocarbon chain region and increasing the water permeability of the bilayer. These results may provide insights into the local cytotoxic side effects of ibuprofen and its underlying molecular mechanisms.Communicated by Ramaswamy H. Sarma.

Ibuprofen changes the physical properties of the membrane.Ibuprofen decreases the packing and intermolecular interaction at the hydrocarbon chain of lipids.Ibuprofen increases the permeability of water and hydrogen peroxide as reactive oxygen species (ROS).Results may shed light on the local cytotoxic side effects of ibuprofen.

Lateralization of the hippocampus: A review of molecular, functional, and physiological properties in health and disease.

The hippocampus is a part of the brain's medial temporal lobe that is located under the cortex. It belongs to the limbic system and helps to collect and transfer information from short-term to long-term memory, as well as spatial orientation in each mammalian brain hemisphere. After more than two centuries of research in brain asymmetry, the hippocampus has attracted much attention in the study of brain lateralization. The hippocampus is very important in cognitive disorders, related to seizures and dementia, such as epilepsy and Alzheimer's disease. In addition, the motivation to study the hippocampus has increased significantly due to the asymmetry in the activity of the left and right hippocampi in healthy people, and its disruption during some neurological diseases. After a general review of the hippocampal structure and its importance in related diseases, the asymmetry in the brain with a focus on the hippocampus during the growth and maturation of healthy people, as well as the differences created in patients at the molecular, functional, and physiological levels are discussed. Most previous work indicates that the hippocampus is lateralized in healthy people. Also, lateralization at different levels remarkably changes in patients, and it appears that the most complex cognitive disorder is caused by a new dominant asymmetric system.

Melatonin: a promising neuroprotective agent for cerebral ischemia-reperfusion injury.

Cerebral ischemia-reperfusion (CIR) injury is initiated by the generation of reactive oxygen species (ROS), which leads to the oxidation of cellular proteins, DNA, and lipids as an initial event. The reperfusion process impairs critical cascades that support cell survival, including mitochondrial biogenesis and antioxidant enzyme activity. Failure to activate prosurvival signals may result in increased neuronal cell death and exacerbation of CIR damage. Melatonin, a hormone produced naturally in the body, has high concentrations in both the cerebrospinal fluid and the brain. However, melatonin production declines significantly with age, which may contribute to the development of age-related neurological disorders due to reduced levels. By activating various signaling pathways, melatonin can affect multiple aspects of human health due to its diverse range of activities. Therefore, understanding the underlying intracellular and molecular mechanisms is crucial before investigating the neuroprotective effects of melatonin in cerebral ischemia-reperfusion injury.

Concentration-dependent mechanism of the binding behavior of ibuprofen to the cell membrane: A molecular dynamic simulation study.

Ibuprofen is a commonly used drug for treating headaches, pain, and fever. The lipid bilayer is the primary and most important interface for drugs to interact with biological systems. However, the molecular interactions between ibuprofen and the cell membrane are not well understood. Our findings suggest that the interactions between ibuprofen and the bilayer involve multiple steps and depend on the concentration of the drug. At low concentrations of ibuprofen, it can bind to the surface of the lipid bilayer. The electrostatic and vdW energies of IBU-lipid at 0 ns of the simulation were -22.5 ± 3.2 and -5.9 ± 1.2 kj.mol-1 Fig. 2. In the following, the vdW energy of the IBU-lipid was increased by around -134.6 ± 3.7 kj.mol-1 whereas the electrostatic energy of the IBU-lipid was significantly decreased. This binding is facilitated by electrostatic and vdW interactions between ibuprofen and the head group of lipids. In the second step, ibuprofen is inserted into the lipid bilayer and positioned at the interface between the bilayer and the aqueous phase. In high concentrations of ibuprofen, it moved to the central region of the lipid bilayer. At this concentration, the physical and structural properties of the cell membrane change significantly. Results from the radial distribution function analysis indicate that at low concentrations, ibuprofen molecules are situated close to the head groups of phosphate groups. However, at high concentrations of ibuprofen, these molecules move to the inner side of the lipid bilayer. In addition, our findings indicate that at low concentrations of ibuprofen, these molecules did not significantly alter the physical properties of the cell membrane. In contrast, at high concentrations of ibuprofen, the physical parameters of the hydrocarbon tails, such as thickness, fluidity, and order, changed dramatically. APL parameter for POPC membrane increased slightly to 0.60 and 0.63 nm2 in the presence of low and high concentrations of ibuprofen molecules. The three-step interaction between ibuprofen and the lipid bilayer involves several events, such as the movement of ibuprofen molecules towards the central region of the lipid bilayer and the deformation and alteration of the structural and stability properties of the cell membrane. These effects are observed only at high concentrations of ibuprofen. It appears that the side effects of ibuprofen overdose are related to changes in the properties of the cell membrane and, subsequently, the function of membrane-anchored target proteins.

The relationship between thyroid deficiency and blood-based biomarkers of cognitive disorders.

OBJECTIVE: Thyroid hormones play an essential role in metabolism regulation and circadian rhythm control. Recent studies approved their role in normal development and healthy function of central nervous system (CNS). The thyroid gland is a component of the hypothalamic-pituitary-thyroid axis disrupted during thyrotoxicosis and hypothyroidism, two main clinical conditions that induce more liability against dementia-related disease. METHOD: In the first step, this study evaluated the circular level of neuropeptide Y (NPY), leptin, oxytocin, and vasopressin in hyperthyroidism and hypothyroidism patients. In the second step, we investigated neurological and cognitive abnormalities by assessment of the hallmark proteins and peptides such as amyloid ß (Aß) variants, glycogen synthase kinase 3ß (GSK-3ß), and tau protein in thyroid-deficient samples. RESULTS: The results show increased content of leptin hormone in patients with hypothyroidism who also manifested high levels of vasopressin. Underactivation and overactivation of the thyroid gland are accompanied by reduced circular oxytocin. We may conclude that thyroid deficiency is associated with neurohormone dysregulation. Interestingly, both patient groups exhibited significant increases in Aß40 and Aß42 levels relative to the control group, which was also accompanied by the rise in GSK-3ß; this might be interpreted as cholinergic system dysfunction and cognitive impairment. The results revealed tau content increased considerably in thyrotoxicosis but did not change significantly in hypothyroidism compared to the control group. CONCLUSION: Therefore, our results have shown that thyroid gland dysfunction is a risk factor for cognitive impairment, mainly through neuroendocrine dysregulation. This study provides a relationship between hyperthyroidism/hypothyroidism and biomarkers of neurological abnormalities in blood serum.

A robust and facile label-free method for highly sensitive colorimetric detection of ascorbic acid in fresh fruits based on peroxidase-like activity of modified FeCo-LDH@WO3 nanocomposite.

Many compounds such as amino acids and oligonucleotides have been shown to effectively change peroxidase-like activity of nanoparticles. While a few studies have focused on mimicking the active site of natural enzymes on nanozymes and thus increasing their substrate affinity. Therefore, in this work, the surface of FeCo@WO3 nanocomposite was modified using guanosine triphosphate (GTP) to mimic the histidine of peroxidase enzyme's active site and its modification was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). Then, the peroxidase-mimicking activity of the modified nanocomposite was tested using a colorimetric method, based on the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). It was found that GTP improves the activity of FeCo@WO3 as a natural peroxidase active site's distal histidine residue. Ascorbic acid (AA) is a powerful antioxidant that induces the reduction of blue color (oxidized TMB) ox-TMB to colorless TMB. The colorimetric method was applied for the sensitive detection of AA in common fruits. The linear range of AA was 10-100 µM with a limit of detection (LOD) of 0.27 µM, which provides a rapid and sensitive method for testing AA in the field of food analysis.

Neuroprotection of fullerene in improving cognitive-behavioral disruptions and neurobiochemical enzymes activities.

Aim: Here, we report the synthesis and evaluation of fullerene C60 nanoparticles' (FC60 NPs) therapeutic efficacy in animals with aluminum-induced oxidative stress. Materials & methods: Effects of FC60 NPs on the altered activity levels of neurobiochemical enzymes and oxidative parameters in brain and liver tissues have been evaluated. Aluminum was injected for 3 weeks and from the beginning of the third week, FC60 NPs were injected for 1 week. Results: Administration of FC60 NPs showed a significant improvement in the altered activity level of the selected markers. Conclusion: Results suggest synthesized FC60 NPs as a therapeutic option for the treatment of neurodegenerative diseases.

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.

State-of-the-art advancement of surface functionalized layered double hydroxides for cell-specific targeting of therapeutics.

Over the years, layered double hydroxides (LDHs) hold a specific position in biomedicine due to their tunable chemical composition and appropriate structural properties. However, LDHs lack adequate sensitivity for active targeting because of less active surface area and low mechanical strength in physiological conditions. The exploitation of eco-friendly materials, such as chitosan (CS), for surface engineering of LDHs, whose payloads are transferred only under certain conditions, can help develop stimuli-responsive materials owing to high biosafety and unique mechanical strength. We aim to render a well-oriented scenario toward the latest achievements of a bottom-up technology relying on the surface functionalization of LDHs to fabricate functional formulations with promoted bio-functionality and high encapsulation efficiency for various bioactives. Many efforts have been devoted to critical aspects of LDHs, including systemic biosafety and the suitability for developing multicomponent systems via integration with therapeutic modalities, which are thoroughly discussed herein. In addition, a comprehensive discussion was provided for the recent progress in the emergence of CS-coated LDHs. Finally, the challenges and future perspectives in the fabrication of efficient CS-LDHs in biomedicine are considered, with a special focus on cancer treatment.

The interaction mechanism of candidone with calf thymus DNA: A multi-spectroscopic and MD simulation study.

In this investigation, the effects of candidone on the structure and conformation of DNA were evaluated by spectroscopic methods, molecular dynamics simulation, and molecular docking studies. Fluorescence emission peaks, ultraviolet-visible spectra, and molecular docking exhibited the complex formation between candidone and DNA in a groove-binding mode. Fluorescence spectroscopy results also showed a static quenching mechanism of DNA in the presence of candidone. Moreover, thermodynamic parameters demonstrated that candidone spontaneously bound to DNA with a high binding affinity. The hydrophobic interactions were the dominant forces over the binding process. Based on the Fourier transform infrared data candidone tended to attach to the A-T base pairs of the minor grooves of DNA. The thermal denaturation and circular dichroism measurements displayed that candidone caused a slight change in the DNA structure, which was confirmed by the molecular dynamics simulation results. According to the obtained findings from the molecular dynamic simulation, the structural flexibility and dynamics of DNA were altered to a more extended structure.

The Association between the Expression of MicroRNA-4270 and MicroRNA-4441 with some Metabolic Factors in Iranian Rheumatoid Arthritis Patients.

MicroRNAs (miRs) play a role in several diseases, such as rheumatoid arthritis (RA). The purpose of this study was to discover new microRNAs and investigate their involvement in RA, examining their connections with inflammation and metabolic markers. New microRNAs related to RA were predicted using Mirbase and TargetScan databases based on RA target genes. The relationships between miRNAs and targets were visualized with Cytoscape software. Real-time polymerase chain reaction confirmed detectable miRNAs and metabolic factors were assessed using immunoassay and spectrometry methods in RA patients and healthy subjects. Four microRNAs (hsa-miR-153-5p, hsa-miR-4270, hsa-miR-4441, and hsa-miR-6754-5p) showed the highest correlation with RA target genes among millions of microRNAs. The expression of miR-146b (fold change=1.8) and miR-4441 (fold change=1.7) was notably reduced, while miR-4270 showed upregulation (fold change=1.8) in plasma from RA patients compared to healthy individuals. MiR-6754 exhibited a decrease (fold change=1.3) but was statistically insignificant. MiR-153-5p expression was undetectable in plasma. Receiver operating characteristic (ROC) curve analysis indicated that miR-4441, with an area under the ROC curve (AUC) of 0.7728, and miR-4270 (AUC=0.7353) were promising biomarkers for RA. The expression of these studied miRNAs significantly correlated with essential clinical characteristics, including liver enzymes, cholesterol, phosphorus, and vitamin D3. Our findings suggest that miR-4270 and miR-4441, present in the circulation, exhibit distinct expression patterns in RA. These microRNAs may serve as links between inflammation and metabolism and represent promising new biomarkers for this disease.

Metabolic Pathways in Breast Cancer Reprograming: An Insight to Non-Coding RNAs.

Cancer cells reprogram their metabolisms to achieve high energetic requirements and produce precursors that facilitate uncontrolled cell proliferation. Metabolic reprograming involves not only the dysregulation in glucose-metabolizing regulatory enzymes, but also the enzymes engaging in the lipid and amino acid metabolisms. Nevertheless, the underlying regulatory mechanisms of reprograming are not fully understood. Non-coding RNAs (ncRNAs) as functional RNA molecules cannot translate into proteins, but they do play a regulatory role in gene expression. Moreover, ncRNAs have been demonstrated to be implicated in the metabolic modulations in breast cancer (BC) by regulating the metabolic-related enzymes. Here, we will focus on the regulatory involvement of ncRNAs (microRNA, circular RNA and long ncRNA) in BC metabolism, including glucose, lipid and glutamine metabolism. Investigation of this aspect may not only alter the approaches of BC diagnosis and prognosis, but may also open a new avenue in using ncRNA-based therapeutics for BC treatment by targeting different metabolic pathways.

A ratiometric fluorescent sensor for detection of metformin based on terbium-1,10-phenanthroline-nitrogen-doped-graphene quantum dots.

Metformin (MTF), an effective biguanide and oral antihyperglycemic agent, is utilized to control blood glucose levels in patients with type II diabetes mellitus, and the determination of its concentration in biological fluids is one of the main issues in pharmacology and medicine. In this work, highly luminescent nitrogen-doped graphene quantum dots (N-GQDs) were modified using terbium (Tb3+)-1,10-phenanthroline (Phen) nanoparticles (NPs) to develop a dual-emission ratiometric fluorescent sensor for the determination of MTF in biological samples. The synthesized N-GQDs/Tb-Phen NPs were characterized using different techniques to confirm their physicochemical properties. The N-GQDs/Tb-Phen NPs showed two characteristic emission peaks at 450 nm and 630 nm by exciting at 340 nm that belong to N-GQDs and Tb-Phen NPs, respectively. The results indicated that the emission intensity of both N-GQDs and Tb-Phen NPs enhanced upon interaction with MTF in a concentration-dependent manner. Also, a good linear correlation between the enhanced fluorescence intensity of the system and MTF concentration was observed in the range of 1.0 nM-7.0 µM and the limit of detection (LOD) value obtained was 0.76 nM. In addition, the prepared probe was successfully used for the estimation of MTF concentration in spiked human serum samples. In conclusion, the reported dual-emission ratiometric fluorescent sensor can be used as a sensitive and simple fluorimetric method for the detection of MTF in real samples.

Smart active-targeting of lipid-polymer hybrid nanoparticles for therapeutic applications: Recent advances and challenges.

The advances in producing multifunctional lipid-polymer hybrid nanoparticles (LPHNs) by combining the biomimetic behavior of liposomes and architectural advantages of polymers have provided great opportunities for selective and efficient therapeutics delivery. The constructed LPHNs exhibit different therapeutic efficacies for special uses based on characteristics of different excipients. However, the high mechanical/structural stability of hybrid nano-systems could be viewed as both a negative property and a positive feature, where the concomitant release of drug molecules in a controllable manner is required. In addition, difficulties in scaling up the LPHNs production, due to involvement of several criteria, limit their application for biomedical fields, especially in monitoring, bioimaging, and drug delivery. To address these challenges bio-modifications have exhibited enormous potential to prepare reproducible LPHNs for site-specific therapeutics delivery, diagnostic and preventative applications. The ever-growing surface bio-functionality has provided continuous vitality to this biotechnology and has also posed desirable biosafety to nanoparticles (NPs). As a proof-of-concept, this manuscript provides a crucial review of coated lipid and polymer NPs displaying excellent surface functionality and architectural advantages. We also provide a description of structural classifications and production methodologies, as well as the biomedical possibilities and translational obstacles in the development of surface modified nanocarrier technology.

An innovative fluorometric bioanalysis strategy towards recognition of DNA methylation using opto-active polymer: A new platform for DNA damage studies by genosensor technology.

Efficient pharmacotherapy of cancer is related to accurate recognition of genetic mutations and epigenetic alterations in the early-stage diagnosis. In the present study, a novel optical genosensor based on toluidine blue as photonic probe was developed to detection of DNA methylation using hybridization of pDNA with cDNA. Biomedical analysis was performed using UV-vis and fluorometric methods. For the first time, this strategy was applied for the distinction of methylated DNA from unmethylated-DNA-based on the interaction of optical probe with methylated-DNA and unmethylated DNA. Fluorescence spectroscopic data showed that poly-toluidine blue could be bind to DNA sequences and lead to different fluorescence patterns and could be used as an efficient geno-platform for the sensitive bioassay of mutation. The excitation and emission wavelengths were 580 and 630 nm, respectively. Non-binding of mismatch sequences with the optical probe was used as negative control. Under optimal conditions, linear range was 1 zM to 0.2 pm and the lower limit of quantitation was obtained as target concentrations ranging 1 zM. The designed genosensor showed high capability to distinct methylation from un-methylated. Therefore, the designed DNA-based bioassay could detect DNA methylation significantly. Finally, bioanalysis of real samples showed that the designed genosensor could use to detect DNA methylation which is a new platform for point of care analysis.