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The electrochemical behavior of ascorbic acid on a cobalt hydroxide modified glassy carbon (CHM-GC) electrode in alkaline solution was investigated. The process of the involved oxidation and its kinetics were established using the cyclic voltammetry, chronoamperometry techniques, as well as by steady state polarization measurements. The results revealed that cobalt hydroxide promotes the rate of oxidation by increasing the peak current; hence ascorbic acid is oxidized at lower potentials, which is thermodynamically more favorable. The cyclic voltammograms and chronoamperometry indicate a catalytic EC mechanism is operative with the electrogeneration of Co(IV) as the electrochemical process. Also, the process is diffusion-controlled and the current- time responses follow Cottrellian behavior. This result was confirmed by steady state measurements. The rate constants of the catalytic oxidation of ascorbic acid and the electron-transfer coefficient are reported.

Alzheimer's disease is characterized by the accumulation of beta-amyloid plaques and neurofibrillary tangles. Effective therapeutic strategies involve inhibiting the formation of beta-amyloid aggregates and destabilizing existing ones. A significant challenge in current treatments is the inability of therapeutic agents to cross the blood-brain barrier, a limitation addressed by employing drug nanocarriers. This study investigates the interactions between memantine, rivastigmine, beta-amyloid structures, and graphene oxide nanocarriers using molecular docking and in silico methods. The goal is to enhance drug development through cost-effective and efficient computational techniques. Results indicate that the binding energies for memantine-beta-amyloid and rivastigmine-beta-amyloid complexes are -9.03 kcal/mol and -7.81 kcal/mol, respectively, suggesting superior stability for the memantine-beta-amyloid complex. The electrostatic energies are -1.91 kcal/mol for memantine and -0.81 kcal/mol for rivastigmine, further supporting the greater stability of the memantine complex. Additionally, memantine's interaction with graphene oxide results in more negative adsorption energy (-92.47 kJ/mol) compared to rivastigmine (-86.36 kJ/mol), indicating a stronger binding affinity. The charge transfer (Q) values are -0.41 kJ/mol for memantine and -0.33 kJ/mol for rivastigmine. The negative enthalpy (ΔH) of -85.71 kJ/mol and Gibbs free energy (ΔG) of -41.52 kJ/mol for the memantine-graphene oxide interaction suggest a spontaneous process. Both memantine and rivastigmine display similar electronic properties, but memantine shows a more effective interaction with graphene oxide, likely due to its amine functional group and spatial configuration. The adsorption energy analysis confirms that memantine forms a more stable complex with graphene oxide than rivastigmine., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Hyaluronic acid (HA) possesses unique viscoelastic properties and low immunogenicity, making it suitable for various biomedical purposes such as viscosupplementation in osteoarthritis treatment, assistance in eye surgery, and wound regeneration. The need for its quantification in human biofluids is crucial in clinical studies. This research work presents a novel approach using paper-based and parafilm-based photochemical techniques, employing triangular silver nanoprisms (TA-AgNPrs) as optical nanoprobes for HA detection in human biofluids. The interaction between HA and TA-AgNPrs leads to a notable change in the absorption spectrum, facilitating rapid and reliable measurement with a detection limit of less than 0.5 μM to 30 mM. The developed colorimetric setups, along with the single-drop parafilm colorimetric substrate, enable fast and on-site HA analysis. This research marks the maiden use of TA-AgNPrs for direct, rapid and sensitive HA detection in real samples, without the need for sample pre-preparation. The use of a digital image analysis strategy enhances the simplicity, affordability, and portability of this sensor, presenting promising potential for monitoring HA levels. This new technique is poised to enable early diagnosis of diseases associated with abnormal HA levels in human biofluids, thanks to its high sensitivity and selectivity in detecting HA., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Taurine is now widely used as a new biomarker for cardiovascular and neurodegenerative diseases. This study discusses the importance of accurately determining taurine biomarker levels in various tissues and fluids for the early diagnosis of important pathologies and diseases. Current methods for taurine analysis face challenges such as low sensitivity, lack of selectivity, and complex procedures. Therefore, an efficient analytical method/technique is urgently needed by clinicians. A new paper-based photochemical method using triangular silver nanoparticles (TA-AgNPs) as optical nanoprobes was developed to detect taurine in human blood plasma and urine samples. This method involves a chemical reaction between taurine and TA-AgNPs, leading to a color change at pH 4.8, which is detected using a paper-based colorimetry (PCD) assay. The reaction is further confirmed by UV-visible spectrophotometry as the interaction between taurine and TA-AgNPs causes a significant change in the absorption spectrum, enabling the rapid and reliable measurement of this important biomarker with a detection limit of less than 0.2 μM to 20 mM. The method has been successfully applied to bioanalyzing taurine in human body fluids. Additionally, it requires optimized single-drop paper/parafilm-based colorimetric devices (OD-PCDs) for in situ and on-demand taurine analysis. This study represents the first use of TA-AgNPs for the specific and sensitive detection of taurine in real samples. The sensor design allows for the direct quantification of biomarkers in biological samples without the need for derivatization procedures or sample preparation. The simplicity and portability of OD-PCDs make them promising for tracking and monitoring. This method is expected to contribute to improving environmental health and occupational safety and represents a significant advancement in colorimetric analysis for the sensitive and selective detection of taurine, potentially providing a platform for the identification of taurine and other biomarkers., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Acetaldehyde, a prevalent carbonyl compound in fermented foods, poses challenges in various applications due to its reactivity. This study addresses the need for efficient acetaldehyde detection methods across biotechnological, environmental, pharmaceutical, and food sectors. Herein, we present a novel colorimetric/UV spectrophotometric approach utilizing gold nanoparticles (AuNPs), particularly gold nano-flowers (AuNFs), for sensitive acetaldehyde identification. The method exhibits a notable sensitivity, detecting acetaldehyde at concentrations as low as 0.1 μM. The mechanism involves the interaction of acetaldehyde molecules with AuNFs, leading to a significant change in the absorbance spectrum, which serves as the basis for detection. Moreover, its applicability extends to human biofluids, notably urine samples. Integration with a cost-effective one-drop microfluidic colorimetric device (OD-μPCD) enables the development of an affordable test strip (CATS). This semi-analytical device, employing a multichannel OD-μPCD, facilitates real-time analysis of acetaldehyde in human samples. Our findings demonstrate the pioneering utilization of AuNPs for selective and sensitive acetaldehyde detection, promising advancements in environmental and occupational safety standards, and laying a foundation for enhanced detection and monitoring of related volatile organic compounds (VOCs)., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The global community is faced with numerous health concerns such as cancer, cardiovascular and neurological diseases, diabetes, joint pain, osteoporosis, among others. With the advancement of research in the fields of materials chemistry and medicine, pharmaceutical technology and biomedical analysis have entered a new stage of development. The utilization of natural oligosaccharides and polysaccharides in pharmaceutical/biomedical studies has gained significant attention. Over the past decade, several studies have shown that chitosan and cyclodextrin have promising biomedical implications in background analysis, ongoing development, and critical applications in biomedical and pharmaceutical research fields. This review introduces different types of saccharides/natural biopolymers such as chitosan and cyclodextrin and discusses their wide-ranging applications in the biomedical/pharmaceutical research area. Recent research advances in pharmaceutics and drug delivery based on cyclodextrin, and their response to smart stimuli, as well as the biological functions of cyclodextrin and chitosan, such as the immunomodulatory effects, antioxidant, and antibacterial properties, have also been discussed, along with their applications in tissue engineering, wound dressing, and drug delivery systems. Finally, the innovative applications of chitosan and cyclodextrin in the pharmaceutical/biomedicine were reviewed, and current challenges, research/technological gaps, and future development opportunities were surveyed., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Parkinson's disease (PD), the second most frequent neurodegenerative illness, is a neurological ailment that produces unintentional or uncontrolled body movements, which should be diagnosed in its early stages to hinder the progression. Monitoring the concentration of α-synuclein (α-Syn) in body fluids can be one of the most efficient ways for PD early detection. In this work, a paper-based electrochemical immunosensor was designed for α-Syn bio-assay in human plasma samples based on encapsulation of the biotinylated antibody on novel dendritic fibrous nanosilica ((KCC-1- nPr -CS 2 )-Ab). For this purpose, a three-electrode system was prepared using stabilization of silver nano-ink on photographic paper. Then, the (KCC-1-NH-CS 2 )-Ab was immobilized on its surface and used to detect the target antigen (α-Syn). After characterization of the prepared substrate by FE-SEM and EDS, the redox behavior of the biosensor was evaluated using chronoamperometry techniques. Under optimal experimental conditions and using a label-free strategy, the engineered immunosensor showed a linear relationship between peak current and antigen concentration in the linear range from 0.002 to 128 ng mL -1 with the lower limit of quantification of 0.002 ng mL -1 . Moreover, this work involves unprecedented use of conductive nano-inks for the manufacture of α-Syn immunosensor, which is aided by the use of a mesoporous silicate dendrimer in encapsulating the α-Syn antibody, thus offering a robust and simple point-of-care device for early PD diagnosis. The ability of the proposed platform to detect small amounts of α-Syn offers a promising approach to developing low-cost, sensitive, and transportable biosensors for Parkinson's disease screening in its early stages., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Biogenic amines (BAs) are a group of organic compounds that are produced through the decarboxylation of amino acids by microorganisms. These compounds are commonly found in a variety of foods and are known to cause adverse health effects if consumed in high concentrations. Therefore, the development of sensitive and rapid detection methods for detection and determination of BAs is essential for ensuring food safety. In this study, a novel colorimetric affordable test strip (CATS) was developed for the colorimetric and naked-eye detection of two BAs of ethylenediamine (EDA) and histamine (HIS) in meat samples. Also, triangular silver nanoparticles (AgNPrs) were used as a diagnostic optical probe, and CATS used as a simple, environmentally friendly, inexpensive diagnostic substrate for on - site recognition of meat spoil. The AgNPrs-based optosensor demonstrated high sensitivity and selectivity towards EDA and HIS, allowing for the detection of low concentrations of the BAs in real food samples such as raw chicken and beef. The system presented a UV-vis technique for HIS and EDA analysis in the linear range of 0.1 μM to 0.01 mM, with an LLOQ of 0.1 μM, and 0.05 to 1 μM, with an LLOQ of 0.05 μM, respectively. Additionally, the performance of the designed CATS in the analysis of produced gases was evaluated, highlighting the potential of this simple and cost-effective strategy for the development of BAs diagnostic kits. This approach provides a simple and cost-effective method for detecting BAs in food, which could be beneficial for ensuring food safety and preventing the harmful effects associated with their consumption., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Air pollution has become a major challenge that threatens human health. The use of respiratory filters is one of the proposed solutions. In this study, using polystyrene (PS) fibers and various nanomaterials, improved respiratory filters were fabricated to remove air pollutants. In this context, ZnO nanoparticles (ZnO NPs) integrated into dendritic structures of KCC-1 silica were used to improve the filters' ability to absorb pollutants. For the first time, the removal of gasses by modified filters with a novel polymeric nanocomposite (PS/ZnO-KCC-1) stabilized on the surface of respiratory filters was investigated. Moreover, two different methods including stabilized- and solution-based techniques were used to prepare the filters with different amounts of ZnO NPs and their efficiency was evaluated. All synthesized nanocomposites and developed filters were characterized by FT-IR, FESEM, TGA and XRD methods. The successful stabilization of nanostructures on the fibers was proved and the performance of the fibers was investigated with some tests, such as pressure drop and removal of suspended particles and CO 2 (89%), NO 2 (86%), and SO 2 (83%) gases. PS/KCC-1-ZnO (5%) has better performance than other prepared fibers. The results showed that the removal of suspended particles in the filter containing ZnO and KCC-1 (M5) nanostructures was improved by 18% compared to the filter consisting of polystyrene fibers. The pressure drop increased with the addition of nanostructures and reached 180 Pa in the M5 filter. The filter containing ZnO NPs showed antibacterial activity against Staphylococcus ( S. ) aureus and Escherichia ( E. ) coli as Gram-positive and Gram-negative model bacteria using the Agar disk-diffusion method. Based on the results, the use of improved respiratory filters is recommended as an effective solution for combating air pollution and protecting human health., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Xanthene and acridine derivatives are interesting organic compounds that are used in different research fields like biomedicine and pharmaceutical science. However, applied catalysts for their synthesis have some limitations such as long reaction times, the need for harsh conditions and low yield. So, discovery of novel catalysts for the synthesis of xanthene and acridine derivatives is highly demanded. To overcome the limitation of previous methods on the efficient synthesis of 1,8-dioxo-octahydroxanthene and 1,8-dioxo-decahydroacridine derivatives, a green heterogeneous organic nano-catalyst (Cu@KCC-1- n Pr-HMTA) was synthesized by covalent attachment of hexamethylenetetramine to the cavities and channels of dendritic mesoporous nanosilica (KCC-1). The prepared nano-catalyst was identified using various spectroscopic and microscopic methods including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray energy diffraction (EDX), EDX mapping and nitrogen adsorption-desorption analysis (BET-BJH). The prepared green nano-catalyst showed a spherical and dendritic structure with a surface area of 65.699 m 2 g -1 , average pore size of 40.78 nm and pore volume of 0.66 cm 3 g -1 . Also, Cu@KCC-1- n Pr-HMTA has many chemo-active sites for the condensation reaction and was used as an efficient nano-catalyst towards one-step synthesis of 1,8-dioxo-decahydroacridine and 1,8-dioxo-octahydroxanthene derivatives from the reaction of aromatic aldehydes, dimedone, and ammonium acetate under solvent-free conditions. Short reaction times of 1 to 5 minutes for 1,8-dioxo-decahydroacridine and 30 to 55 minutes for 1,8-dioxo-octahydroxanthene derivatives, high yields and mild reaction conditions are advantages of the proposed synthetic method. It is hoped that the engineered nano-catalyst will be used for the synthesis of other organic compounds in the future., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

For the first time, a novel aptamer was designed and utilized for the selective detection of rivaroxaban (RIV) using the integration of bioinformatics with biosensing technology. The selected aptamer with the sequence 5'-TAG GGA AGA GAA GGA CAT ATG ATG ACT CAC AAC TGG ACG AAC GTA CTT ATC CCC CCC AAT CAC TAG TGA ATT-3' displayed a high binding affinity to RIV and had an efficient ability to discriminate RIV from similar molecular structures. A novel label-free electrochemical aptasensor was designed and fabricated through the conjugation of a thiolated aptamer with Au nanoparticles (Au-NPs). Then, the aptasensor was successfully applied for the quantitative determination of RIV in human plasma and exhaled breath condensate (EBC) samples with limits of detection (LODs) of 14.08 and 6.03 nM, respectively. These valuable results provide ample evidence of the green electrogeneration of AuNPs on the surface of electrodes and their interaction with loaded aptamers (based on Au-S binding) towards the sensitive and selective monitoring of RIV in human plasma and EBC samples. This bio-assay is an alternative approach for the clinical analysis of RIV and has improved specificity and affinity. As far as we know, this is the first time that an electrochemical aptasensor has been verified for the recognition of RIV and that allows for the easy, fast, and precise screening of RIV in biological samples.

Various nanostructures have been used to improve the performance of nanocomposite membranes. Dendritic fibrous nanosilica (DNFS) is a new nanostructure and its performance as an adsorbent for the removal of pigments has been investigated. In this study, a type of modified dendritic fibrous nanosilica containing CS 2 groups (KCC-1-NH-CS 2 ) was synthesized and inserted as an additive into nanocomposite acrylonitrile-butadiene-styrene (ABS) membranes. Due to its high surface area and unique functional groups, this additive can improve the membrane's ability to remove dyes from aqueous media. Synthesized nanostructures and membranes were characterized by different analysis. The results showed that the water contact angle as a measure of surface hydrophilicity in membrane M 5 compared to membrane M 1 decreased from 79° to 67°. Water absorption (swelling degree) in membrane M 5 increased by more than 100% compared to the bare membrane. Also, this membrane, despite having high porosity (42%) and improved flux (35 L m -2 h -1 ), has a better efficiency in removing dyes (MG: 99%, MB: 98%, MO: 82%) in comparison with other reported works., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In the present work, an innovative biocompatible heterogeneous organo-nanocatalyst is prepared based on the grafting of arginine amino acid on the channels and pores of dendritic fibrous nano silica. The designed organo-nanocatalyst (KCC-1-nPr-NH-Arg) was characterized by using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, map analysis, and adsorption/desorption instruments. The results of analysis show that the engineered catalyst has uniform fibrous spheres and dendritic structure with high surface area (104.9 m 2 /g) and great pore volume (0.83 cm 3  g -1 ). Because of exceptional dendritic structure of the prepared organo-nanocatalyst, the active sites are available and the difusion and adsorption capacity of the reagents and products increase in the pores and channels of the catalyst. Hence, KCC-1-nPr-NH-Arg was used as an capable heterogeneous basic nanocatalyst in the synthesis of 1,8-dioxo decahydroacridine derivatives from the one-pot four component reactions of aromatic aldehydes, dimedone, and ammonium acetate in solvent free conditions with shorter reaction times (13-35 minutes) and higher yields (94%-98%) in evaluation with other reported works. It is expected that the green organo-nanocatalyst can be used to synthesize other organic compounds., (© 2022 John Wiley & Sons Ltd.)

The endocannabinoid system (ECS) is a complex of neurotransmitters in the central nervous system and plays a key role in regulating cognitive and physiological processes. 2-Arachidonoylglycerol (2-AG) is one of the imperative endocannabinoids that play key roles in the central nervous system. It acts as a signaling lipid and activates the cannabinoid CB1 receptor. In addition, 2-AG is involved in a variety of physiological functions such as energy balance, emotion, pain sensation, cognition, and neuroinflammation. So, rapid and specific diagnosis of 2-AG is of great importance in medical neuroscience. The development of new methods in this area has been one of the most important research areas in recent years. Herein, an innovative immunosensor is developed for quantification of 2-AG. For this means, gold nanostars (GNS) were synthesized and conjugated with a specific biotinylated antibody against 2-AG. The resultant bioconjugate, a bioreceptor with GNS, was immobilized on the surface of a gold electrode and used for the detection of the antigen based on the immunocomplex formation followed by analysis using different electrochemical techniques. For the first time, 2-AG protein was measured with an excellent linear range of 0.48-1 ng mL -1 and lower limit of quantification of 0.48 ng L -1 by the electroanalysis method. The engineered immunosensor showed high sensitivity and specificity in the presence of interfering antigens, proving its utility in neurological disorder detection. This immunosensor is the first sandwich type immunoassay for the detection of 2-AG in real samples and the first innovation of designing a novel sandwich type immunosensor for this analyte. Also, excellent analytical results are other advantages of this biosensor for the detection of 2-AG in human plasma samples and serum samples of rats under sleep deprivation. So, this is the first report of an immunosensor of 2-AG using a sandwich type immunosensor., Competing Interests: The authors declare that there are not competing financial interests to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

An innovative nanocatalyst (KCC-1-nPr-Met) has been prepared from the covalent attachment of metformin on the channels and the pores of n-propyl amine functionalized dendritic fibrous nanosilica (DFNS) and used towards efficient, green, and high yield synthesis of tetrahydro-4H-chromenes derivatives by one-pot three-component reaction of aromatic aldehydes, malononitrile, and dimedone in H 2 O-EtOH at room temperature. The designed nanocatalyst has been characterized by energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and adsorption/desorption analysis (BET) techniques. Also, field emission scanning electron microscopy (FE-SEM) was used to study the morphology of prepared nanocatalyst. The engineered nanocatalyst with uniform fibrous spheres has dendritic structure, high pore volume (0.35 cm 3 /g), and great surface area (178 m 2 /g). Hence, the specific dendritic structure of the prepared nanocatalyst not only improve the diffusion ability of the reactants and products, but also, increase the availability of dynamic sites in the pores and channels of the catalyst. According to the obtained results, a unique strategy was proposed towards the synthesis of important biologically active scaffolds in the presence of nontoxic and environmental friendly nanocatalyst and media. Milder reaction conditions (room temperature), shorter reaction times (5-30 minutes), excellent yields (92%-98%) of the products with higher purity, very simple workup procedure, and using of EtOH: H 2 O as a green solvent are the advantages of the presented work., (© 2021 John Wiley & Sons Ltd.)

During the twentieth century, ractopamine (RAC) as one of the important and frequently used feed additives and doping agents has attracted considerable attention in the animal breeding industry and sports competitions. Due to the low metabolism rate of RAC, it is accumulated in livestock tissues. By consuming food, the residues enter the human body causing hazardous side effects including tachycardia, palpitations, and headache. So, sensitive identification of this compound is desirable to combat illicit use and protect food safety. Here, a novel nanomaterial is manufactured based on the functionalization of dendritic fibrous nanosilica with dipenicillamine (KCC-1-NH-DPA). Synthesised advanced nanomaterial was used for the encapsulation of specific DNA-aptamer and incubated on the surface of gold electrode modified by poly(β-cyclodextrin) P(β-CD) which provided the high surface area, excellent mechanical and thermal stability for the dens-loading of encapsulated aptamer. The green platform was provided an efficient apta-platform for the specific recognition of RAC in human biofluids. Electroanalysis of RAC was performed based on "signal ON" protocol. The modified gold electrode by P(β-CD)-(KCC-1-NH-DPA) was used to improve the conductivity and function of the aptasensor towards sensitive identification of RAC in human real sample. Cyclic voltammetry, differential voltammetry, square wave voltammetry, and chronoamperometry techniques were exploited for the measurement of RAC in the concentration range of 0.1 fM to 0.1 mM. Furthermore, the lower limit of quantification (LLOQ) of engineered aptasensor was obtained as 0.1 fM. It is worth noting that the proposed electrochemical aptasensor showed excellent stability, selectivity and performance in standard and human plasma samples. It is important to point out that, synergetic effect of DFNS with high surface to volume, P(β-CD) as conductive substrate and selective aptamer in the fabricated biodevice lead to highly sensitive and selective biosensor for the biomedical analysis of clinical samples. This platform will be provide a new horizon for the application of advanced nanomaterials in biomedical science based POC analysis., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this work, an innovative nanocatalyst (Cu/SiO 2 -Pr-NH-Benz) was synthesized and applied to coupling and click reaction in an aqueous solution. This work reports an efficient and straightforward approach for synthesizing diverse propargylamine and 1,2,3-triazole derivatives in excellent yield and short-time reaction. Also, a novel method involving the Cu NPs supported on the SiO 2 nanocatalyst as a heterogeneous novel catalyst for the " one-pot " three-component A 3 -coupling of aldehyde, amine, and alkynes and " one-pot " click reaction between alkyne, benzyl halide, and sodium azide in the water at room temperature was developed. Significant advantageous such as enhanced catalytic activity with efficient recycling for the one-pot synthesis of 1,4-disubstituted triazoles and propargyl amine derivatives and in green condition were observed. Also, after five successive reactions, the catalytic activity of recycled Cu/SiO 2 -Pr-NH-Benz remained high without significant loss in its intrinsic activity., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s).)

Wrinkled fibrous nanosilica (WFNS) which functionalized by ionic liquid modified Fe 3 O 4 NPs and CuI salts has been synthesized and characterized with FE-SEM, TEM, FT-IR, FAAS, EDX, and, XRD, VSM, and BET-BJH analysis. This new and effective magnetic ceramic nanocatalyst has been applied towards rapid synthesis of N -sulfonylamidines using reaction of phenyl acetylene, substituted sulfonyl azide and various amines under solvent-free conditions in very short reaction time. Higher catalytic activity CuI/Fe 3 O 4 NPs@IL-DFNS in the reaction is because of special structure of DFNS and existence of ionic liquids on its pores which act as a robust anchors to the loaded various nano-particles. So, this lead to no leaching of them from the pore of the composite. Shorter reaction time, higher yield, recovery of the catalyst using an external magnet and its reusability for 8 series without noteworthy reduction in its activity are the advantages of newly synthetic catalyst toward efficient synthesis of N -sulfonylamidines., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s).)

A novel folic acid functionalized terbium-doped dendritic fibrous nanoparticle (Tb@KCC-1-NH 2 -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-NH 2 -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-NH 2 -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-NH 2 -FA were synthesized using green and hydrothermal method; the process was simple with good productivity and desired nanocomposite was non-toxic., (© 2020 John Wiley & Sons Ltd.)

Dye removal from industrial waste water has become an important issue. The highvisibility, undesirability and recalcitrance are the significant environmental problemfor the dyes. In the present work,β-cyclodextrin functionalized KCC-1 (KCC-1-NH-β-CD)was synthesized and utilized to the removal of hazardous malachite green. In order to study the morphology of the synthesized nano adsorbent, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were obtained from the surface of the sample. Additionally, the functionalization of KCC-1 with β-cyclodextrin was confirmed with Furrier Transform Infrared spectroscopy (FTIR). The textural property of KCC-1 was verified using nitrogen adsorption/ desorption analysis (BET equation). UV-Vis spectroscopy utilized for the investigation of malachite green by KCC-1-NH-β-CD. Specific surface area of the adsorbent was calculated to be 140 m 2 /g and it can be stated that the synthesized nano adsorbent has high removal efficiency. It should be noted that the adsorption capacity of the employed nano adsorbent was more than 95%, which could be attributed to high porosity of β-cyclodextrin functionalized KCC-1., (© 2020 John Wiley & Sons Ltd.)

Haemophilus Influenza leads to respiratory infections such as sinusitis, acute otitis media, pneumonia and bronchitis. In addition, it causes invasive infections such as cellulite, septic arthritis, and meningitis. Therefore, quick and sensitive detection of H. influenza is of great importance in medical microbiology. In this study, a novel DNA-based bioassay was developed to the monitoring of Haemophilus influenza genome in human plasma samples using binding of pDNA with cDNA. DNA hybridization strategy was used to investigation of DNAs binding. For this purpose, silver nanoparticle doped graphene quantum dots inks functionalized by D-penicillamine (Ag NPs-DPA-GQDs) were synthesized and deposited on the surface of glass carbon electrode (GCE). Also, gold nanoparticles functionalized with cysteamine (CysA-AuNPs) were deposited on the surface of the Ag-DPA-GQDs modified GCE. Afterward, thiolated DNA probe was immobilized on the surface of the modified electrode. DNA hybridization was monitored using square wave voltammetry (SWV) technique. Engineered genosensor indicated good performance with high specificity and sensitivity for detection of Haemophilus influenza genome. Under optimal conditions, linear range and low limit of quantitation (LLOQ) were obtained as target concentrations ranging from 1 pM-1 ZM and 1 ZM, respectively. The designed biosensor also showed high capability of discriminating one-base, two-base and three-base mismatched sequences. Also, the prepared genosensor could be easily regenerated and reused to evaluate hybridization process., Competing Interests: Declaration of competing interest All the authors (A. Saadati, S. Hassanpour, M. Hasanzadeh and N. shadjou) have read, approved and made substantial contributions for the manuscript. None of the original material contained in this manuscript has been previously published nor is currently under review for publication elsewhere. Besides, authors declare no conflict of interests and/or commercial products or companies., (Copyright © 2020. Published by Elsevier B.V.)

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-NH 2 -FA). Using this probe, fluorescence signals was emitted by Tb@KCC-1-NH 2 -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-NH 2 -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-NH 2 -FA with FR-positive HT 29 cancer cells. The specificity of Tb@KCC-1-NH 2 -FA towards FR-positive cells was approved by staining HEK 293 cells as FR-negative cells with Tb@KCC-1-NH 2 -FA which obtained results approved selective differentiation of normal cells with the FA-decorated nanomaterials. The cytotoxicity of Tb@KCC-1-NH 2 -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 × 10 3 cells/mL with lower limit of detection (LLOQ) of 500 cells/mL. Due to the room temperature stability of Tb@KCC-1-NH 2 -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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A low cost, sensitive and selective electrochemical imprinted biosensor for horseradish peroxidase-conjugated prostate-specific antigen (PSA) was designed and prepared based on the combination of Toluidine blue (TB) and self-assembly surface molecular imprinting technique. Poly toluidine blue [P(TB)] provided high surface area for dense loading of HRP-PSA antibody on GCE surface. P(TB), as supporting material, could effectively enhance imprinting efficiency and the electrode conductivity and facilitate electron transfer. The imprinted biosensor was characterized through Field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDX) and electrochemical methods. The proposed biosensor indicates very highly electrocatalytical activity for the reduction of hydrogen peroxide (H 2 O 2 ). Also, engineered biosensor was used for determination of H 2 O 2 by different electrochemical techniques including differential pulse voltammetry, square wave voltammetry and chronoamperometry. Under the optimized conditions, the proposed bio-imprinted polymer exhibit excellent electrocatalytical activity toward the reduction of H 2 O 2 with wide linear range of 0.001 to 40 mM and a low limit of quantification (LLOQ) of 1 μM., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This review (with 118 refs.) discusses the progress made in electroanalytical methods based on the use of organic and inorganic nanomaterials for the determination of bacteria, specifically of E. coli, Salmonella, Staphylococcus, Mycobacterium, Listeria and Klebsiella species. We also discuss advantages and limitations of electrochemical methods. Strategies based on the use of aptamers, DNA and antibodies are covered. Following an introduction into electrochemical biosensing, a first large section covers methods for pathogen detection using metal nanoparticles, with subsections on silver nanoparticles, gold nanoparticles, magnetic nanoparticles and carbon-based nanomaterials. A second large section covers methods based on the use of organic nanocomposites, graphene and its derivatives. Other nanoparticles are treated in a final section. Several tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses challenges, and gives an outlook on potential future trends. Graphical abstract This review demonstrates the progress made in electroanalytical methods based on the use of organic and inorganic nanomaterials for the detection and determination of pathogenic bacteria. We also discuss advantages and limitations of electrochemical methods. Strategies based on the use of aptamers, DNA and antibodies are covered.

Ovarian cancer is the first and most important cause of malignancy death in women. Mucin 16 or MUC16 protein also known as carcinoma antigen 125 (CA 125) is the most commonly used glycoprotein for early stage diagnosis of ovarian cancer. In this work, a novel paper-based bio-device through hand writing of Ag/RGO (silver nanoparticles/reduced graphene oxide) nano-ink on the flexible paper substrate using pen-on-paper technology was developed. The prepared interface was used to the recognition of CA 125 protein in human biofluid. For this purpose, Ag/rGO nano-ink was synthesized by deposition of Ag nanoparticles onto graphene oxide sheets and the reduction of graphene oxide to rGO simultaneously. Conductivity and resistance of conductive lines were studied after drawing on photographic paper. Subsequently, to prepare a new and unique immuno-device, paper electrode modified by cysteamine caped gold nanoparticles (CysA/Au NPs) using electrochemical techniques. CysA is bonded by sulfur atoms with Au (CysA/Au NPs), and from the amine group with hydroxyl and carboxyl groups of Ag/RGO nano-ink deposited on the surface of paper-based electrodes (CysA/Au NPs/Ag-rGO). Then, anti-CA 125 antibody was immobilized on the electrode surface through Au NPs and CA 125 positively charged amine groups interaction. Atomic force microscopy, Transmission electron microscopy, Field emission scanning electron microscopy, and dynamic light scattering, were performed to identify the engineered immunosensor. Using chronoamperometry technique and under the optimized conditions, the low limit of quantitation (LLOQ) for the proposed immunoassay was recorded as 0.78 U/ml, which this evaluation was performed at highly linear range of 0.78-400 U/ml. The high sensitivity of the electrochemical immunosensor device is indicative of the ability of this immuno-device to detect early stages ovarian cancer., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Growth factors are necessary for proper and efficient wound closure and tissue regeneration. Epidermal growth factor (EGF) is one of the key signaling molecules in stimulating epithelial cell motility, making it a required factor for re-epithelialization. Increased EGF expression is likely to be a strong prognostic and predictive feature in multiple tumor types and determination of EGF may product remarkable diagnosis benefits. Thus, identification and quantification of EGF in biomedical fields are particularly important. Affinity chromatography, immunohistochemical methods and ELISA, conventional methods for EGF detection, requiring high-cost and complicated instrumentation, take too much time and offer deficient sensitivity and selectivity, which restrict their usage in real applications. Hence, it is essential to design and build enhanced systems and platforms for the recognition and quantification of protein biomarkers. In the past few years, bio-assays have been received noticeable attention for the detection of EGF owing to their high sensitivity, selectivity, accuracy, fast response, and low cost. Since the role and importance of developing aptasensors in cancer diagnosis is undeniable. In this review, electrochemical biosensors, which have been applied by many researchers for EGF cancer biomarker detection, have been mentioned and merits and demerits of them have been explained and compared. Efforts related to design and development of aptamer-based biosensors using nanoparticles for sensitive and selective detection of EGF have been reviewed considering: Aptamer importance as recognition elements, principal, application and the recent improvements and developments of aptamer based optical and electrochemical methods. In addition, commercial biosensors and future perspectives for rapid and on-site detection of EGF have been summarized., (Copyright © 2019. Published by Elsevier B.V.)

Early stage diagnosis of breast cancer by monitoring the proteins in human biological fluids is the best method and the first section toward efficient therapy, delaying metastasis and hindrance mortality. In this study, graphite ink was synthesized and combined with CA 15-3 antibody in order to develop a novel immunosensor for detection of CA 15-3, breast cancer biomarker. Conductivity of bioink was examined by designing various conductive patterns on paper using a rollerball pen. Electrochemical behavior of engineered immunosensor was evaluated through employing sensitive diagnostic technique, DPV (differential pulse voltammetry). Under optimal conditions, the linear concentration range and low limit of quantification (LLOQ) of designed immunosensor was 15-250 U/mL and 15 U/mL, respectively. The process was successfully applied to assay of breast cancer biomarker (CA15-3) in unprocessed human plasma specimens., (Copyright © 2019. Published by Elsevier B.V.)

Functionalized fibrous nano-silica (KCC-1) was applied to specific electrochemical detection of HT 29 colorectal cancer cells based on folate (FA)/folate receptor (FR) interactions. KCC-1 fibrous materials were synthesized using a hydrothermal method and then functionalized with FA molecules to produce KCC-1-NH 2 -FA nanoparticles. The KCC-1-NH 2 -FA fibrous nanoparticles offer favorable bleaching stability and exceptional surface area-to-volume ratio which provide facility to design more sensitive cytosensors. The morphology, size and surface charge of KCC-1, KCC-1-NH 2 and KCC-1-NH 2 -FA were approved by field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential, respectively. The porosity of the negatively charged KCC-1-NH 2 -FA was also tested with Brunauer-Emmett-Teller (BET) which approves the high surface area-to-volume ratio of the KCC-1 based materials. Flow cytometry and fluorescence imaging were applied to approve quantitative and qualitative attaching of KCC-1-NH 2 -FA to the HT 29 FR-positive cancer cells. Also, the specific capturing of the nanoparticles were approved by FR-negative HEK 293 normal cells as FR-negative cells through cellular uptake assay which showed the smart differentiation by KCC-1-NH 2 -FA nanomaterials. The cytotoxicity results revealed the biocompatible nature of KCC-1 based materials, implying that the developed method could be used in in vivo applications under the optimized conditions. The developed cytosensor response is linear from 50 to 1.2 × 10 4 cells/mL with a lower limit of detection (LLOQ) of 50 cells/mL. As advantage of the developed cytosensor is simple and provides excellent specificity and sensitivity which enables us to design point of care devices for clinical uses., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ovarian cancer (OC) is known to be one of the most lethal malignancies associated with women disease. The CA-125 protein is a repetitive epitope of MUC-16, which plays key role in enhancing the proliferation of cancer cells and inhibiting anticancer immune responses. It is the most widely used biomarker for early stage diagnosis of OC. Also it is the only serum marker which currently used in clinical diagnosis. Monitoring of CA-125 protein in the serum sample is also valuable in evaluating the response of ovarian cancer to treatment. In this research, a novel immunoassay based on immobilization of CA-125 antibody on the biointerface of silver nanoparticles modified graphene quantum dots ink (Ag NPs-GQDs) was successfully designed to recognition of CA-125 protein in a human plasma sample. The supplied immunoassay presents the proper ability to detect and determine the amount of CA-125 biomarker in low concentrations of CA-125 biomarker. The proposed immunosensor was employed for the detection of CA-125 using differential pulse voltammetry (DPVs) and square wave voltammetry (SWVs) techniques. The proposed interface leads to enhancement of accessible surface area for immobilizing a high amount of anti-CA-125 antibody, increasing electrical conductivity, boosting stability, catalytic properties and biocompatibility. Under the optimized operating conditions, the low limit of quantitation (LLOQ) for the proposed immunosensor was recorded as 0.01 U/mL, which this evaluation was performed at highly linear range of 0.01-400 U/mL. The proposed immunoassay was successfully applied for the monitoring of CA-125 in unprocessed human plasma samples., (Copyright © 2019. Published by Elsevier B.V.)

A novel electrochemical sensor was developed towards recognition of malondialdehyde (MDA) with modifying the glassy carbon electrode (GCE) by self-assembled riboflavin-taurine (RFPT) as organic substrate and silver nanoparticle (Ag NPs) as inorganic nano-catalyst. Therefore, a novel biocompatible and anti-bacterial substrate were prepared for the construction of electrode. In proposed sensor, the RF-PT polymer film led to the emergence of electroactive and suitable substrate for the immobilization of Ag NPs. The use of the proposed nano-hybrid significantly amplified the electrochemical signals the redox behavior was investigated using various electrochemical methods including cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and linear sweep voltammetry (LSV). It is the adaptation of the established RF-PT-Ag NPs organic-inorganic hybrid for a selective, robust, and generalizable sensing system that is the emphasis of this work. The results show that the proposed platform has a good sensitivity in the detecting of MDA with a low limit of quantification (LLOQ) of 0.59 ± 0.05 μM. In addition, the modified electrode reveals promising efficiency against MDA oxidation and its side-products destructive effects. For the first time, the engineered sensor was used to non-invasive determination MDA in exhaled breath condensate (EBC) samples without the need to extra sample preparation steps. The results show RF-PT-AgNPs as a novel biocompatible interface can provide appropriate, reliable, in-expensive, fast, and user-friendly diagnostic tools in the detection of MDA in human real samples., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The rapid and accurate determination of the level of taurine biomarker in various tissues and body fluids can be of great interest in the early diagnosis of several important pathologies and diseases. For the first time, this study reports on the electropolymerization of a low toxic and biocompatible nanocomposite "poly(aspartic acid)-graphene quantum dots (GQDs)" as a novel strategy for surface modification of glassy carbon electrode and preparation a new interface for measurement of taurine. Electrochemical deposition, as a well-controlled synthesis procedure, has been used for subsequently layer-by-layer preparation of GQDs nanostructures on poly(aspartic acid) using cyclic voltammetry techniques in the regime of -1.5 to 2 V. The field emission scanning electron microscopy indicated immobilization of uniformly GQDs onto poly(aspartic acid) film. The modified electrode appeared as an effective electroactivity for detection of taurine biomarker using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry. Enhancement of peak currents is ascribed to the fast heterogeneous electron transfer kinetics that arise from the synergistic coupling between the excellent properties of poly(aspartic acid) as semiconducting polymer, GQDs as high density of edge plane sites, and subtle electronic characteristics to chemical modification. Under the optimized analysis conditions, the prepared sensor for detection of taurine showed a low limit of quantification 0.001mM. Finally, the resulting prepared sensor allow the quantification of these biomarkers directly in biological samples without need of derivatization schemes or sample pretreatment., (Copyright © 2018 John Wiley & Sons, Ltd.)

The rapid and accurate determination of the level of taurine biomarker in various tissues and body fluids can be of great interest in the early diagnosis of several important pathologies and diseases. In the present study, an innovative electrochemical interface for quantitation of taurine based on ternary signal amplification strategy was fabricated. In this work, silver nanoparticles were electrodeposited onto green and biocompatible nanocomposite containing α-cyclodextrin as conductive matrix. Therefore, a double layer film based on α-cyclodextrin and silver nanoparticles was exploited to develop a highly sensitive electrochemical sensor for detection of taurine. Fully electrochemical methodology was used to prepare a transducer on a glassy carbon electrode which provided a high surface area towards sensitive detection of taurine biomarker. The surface morphology of electrode surface was characterized by high-resolution field emission scanning electron microscope (FE-SEM). The proposed sensing platform provides a simple tool for taurine detection. The calibration curve for taurine concentration was linear in 0.7 nM to 0.1 mM with low limit of quantification of 0.7 nM. The practical analytical utility of the modified electrode was illustrated by determination of taurine in unprocessed human plasma samples with recovery of 90.8% to 104%., (© 2018 John Wiley & Sons, Ltd.)

Ovarian cancer, as one of the most life-threatening malignancies among women worldwide, is usually diagnosed at the late stage despite up regulation of molecular markers such as carcinoma antigen 125 (CA 125) at the early stages of the malignancy. CA 125 is the only tumor marker recommended for clinical use in the diagnosis and management of ovarian cancer. The potential role of CA-125 for the early detection of ovarian cancer is controversial and has not yet been adopted for widespread screening efforts in asymptomatic women. Therefore, early detection of CA 125 in human biofluids is highly demanded. In the present study, a novel method was proposed for the fabrication of electrochemical immunosensor based reduced graphene oxide (RGO). Cysteamine capped gold nanoparticle (Cys-AuNPs) were deposited over the surface of ERGO probe using electrophoretic deposition method. These Cys-AuNPs/ERGO probes provide the favorable sites to attach the monoclonal antibody specific to CA 125 antigen. Cyclic voltammetry (CV), and square wave voltammetry (SWV) were applied for the electrochemical recognition of the biolayer. The represented signals demonstrates excellent figure of merits and good capability of the engineered immunosensor towards sensitive detection of CA 125. Quantitative measurements of CA 125 in human plasma samples have been demonstrated, showing the potential of the practical application of this novel immunosensor for the analysis of this biomarker in blood serum samples. This immunosensor has the ability of direct electron transfer as compared to earlier reported electrochemical immunosensors based electrochemical methods. Further, this immunosensor provides a very suitable and convenient alternative to replace the expensive commercially available methods such as immunohistochemistry. The following regression equation between the electrochemical current response and the CA 125 concentration range from 0.1 to 400 U/mL was found. The low limit of quantification for this immunosensor was 0.1 U/mL. To the best of our knowledge, this is the first reported on the direct immobilization of antibody on the surface of Cys-AuNPs/ERGO for fabrication of immunosensors., (Copyright © 2018. Published by Elsevier B.V.)

Early stage diagnosis of cancer by monitoring the cancer biomarkers in human biological fluids is the excellent tool and the first step toward adopting efficient therapy, hindering metastasis and reducing mortality rate. An ultrasensitive electrochemical immunosensor for quantitation of tumor suppressor protein Carcinoma Antigen 15-3 (CA 15-3) based on ternary signal amplification strategy was fabricated. In this work, the antibody (horseradish peroxidase (HRP)-Labeled anti CA 15-3) was immobilized onto a green and biocompatible nanocomposite containing gold nano-shrub (Au NSs) electrochemically assembled onto thiolated graphene quantum dots (GQDs/CysA (Cysteamine)). Therefore, a novel multilayer film based on GQDs, CysA, and Au NSs was exploited to develop a highly sensitive immunosensor for detection of CA 15.3. Fully electrochemical methodology was used to prepare a new transducer on a gold surface which provided a high surface area to immobilize a high amount of the anti-CA 15.3. Under optimized condition the calibration curve for CA 15.3 concentration was linear in the range of 0.3-1 U/mL and 2-250 U/mL with detection limit of 0.011 U/mL. The method was applied to the assay of CA 15.3 in malignant cell line lysates of human breast adenocarcinoma cell line-MCF-7., (Copyright © 2018. Published by Elsevier B.V.)

Folate receptor (FR) is overexpressed in various cancer cells while its expression in normal cells is restricted. The present study provides a new folic acid/folate (FA) functionalized nanomaterials to sense and the differentiation of the cancer cells from normal ones. The reported nanoprobe is based on the mesoporous materials that are functionalized with FA to specify the FR overexpressed cancerous cells. MCF 7 cell lines were used as a model to show the ability of the developed probe for cancer cell detection. The selective binding of FA to FR-positive cells causes the endocytosis of the mesoporous materials into the cells where it can be observed by fluorescence microscopy images. The specific nature of the binding of the FA functionalized mesoporous silica prevents the false detection of normal cells from cancerous cells even in the presence of each other. The cytotoxicity of the n-Pr-NH 2 -MCM 41-FA on the MCF 7 cells was investigated using MTT assay. The reported method can detect the MCF 7 cells from 100 to 1000 cells/mL. This method provides a selective and nontoxic approach towards detection of breast cancer cell lines while it can be developed as a point of care (POC) device for early detection of cancer. Finally, the MCF 7 cancer cells were treated with doxorubicin anti-cancer drug and our device detect the trace amount of MCF 7 based on their electrochemical activity., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The genetic disorder phenylketonuria (PKU) is the inability to metabolize phenylalanine because of a lack of the enzyme phenylalanine hydroxylase. Phenylalanine is used to biochemically form proteins, coded for by DNA. The development of an apta-assay for detection of l-Phenylalanine is presented in this work. A highly specific DNA-aptamer, selected to l-Phenylalanine was immobilized onto a gold nanostructure and electrochemical measurements were performed in a solution containing the phosphate buffer solution with physiological pH. We have constructed an aptamer immobilized gold nanostructure mediated, ultrasensitive electrochemical biosensor (Apt/AuNSs/Au electrode) for l-Phenylalanine detection without any additional signal amplification strategy. The aptamer assemble onto the AuNSs makes Apt/AuNSs/Au electrode an excellent platform for the l-Phenylalanine detection in physiological like condition. Differential pulse voltammetry were used for the quantitative l-Phenylalanine detection. The Apt/AuNSs/Au electrode offers an ultrasensitive and selective detection of l-Phenylalanine down to 0.23 μM level with a wide dynamic range from 0.72 μM-6 mM. The aptasensor exhibited excellent selectivity and stability. The real sample analysis was performed by spiking the unprocessed human serum samples with various concentration of l-Phenylalanine and obtained recovery within 2% error value. The sensor is found to be more sensitive than most of the literature reports. The simple and easy way of construction of this apta-assay provides an efficient and promising diagnosis of phenylketonuria., (Copyright © 2018. Published by Elsevier B.V.)

Caspase-3 plays a vital role in intrinsic and extrinsic pathways of programed cell death and in cell proliferation. Its detection is an important tool for early detection of some cancers and apoptosis-related diseases, and for monitoring the efficacy of pharmaceuticals and of chemo- and radiotherapy of cancers. This review (with 72 references) summarizes nanomaterial based methods for signal amplification in optical methods for the determination of caspase-3 activity. Following an introduction into the field, a first large section covers optical assays, with subsections on luminescent and chemiluminescence, fluorometric (including FRET based), and colorimetric assays. Further section summarize methods for bioimaging of caspase-3. A concluding section covers current challenges and future perspectives. Graphical Abstract ᅟ.

In the present study, the interaction of human serum albumin (HSA) with some cardiovascular drugs (CARs) under physiological conditions was investigated via the fluorescence spectroscopic and Fourier transform infrared spectroscopy. The CAR included Captopril, Timolol, Propranolol, Atenolol, and Amiodarone. Cardiovascular drugs can effectively quench the endogenous fluorescence of HSA by static quenching mechanism. The fluorescence quenching of HSA is mainly caused by complex formation of HSA with CAR. The binding reaction of CAR with HSA can be concluded that hydrophobic and electrostatic interactions are the main binding forces in the CAR-HSA system. The results showed that CAR strongly quenched the intrinsic fluorescence of HSA through a static quenching procedure, and nonradiation energy transfer happened within molecules. Fourier transform infrared spectroscopy absorption studies showed that the secondary structure was changed according to the interaction of HSA and CAR. The binding reaction of CAR with HSA can be concluded that hydrophobic and electrostatic interactions are the main binding forces in the CAR-HSA system. The results obtained herein will be of biological significance in pharmacology and clinical medicines., (Copyright © 2018 John Wiley & Sons, Ltd.)

This study reports on the electropolymerization of a low toxic and biocompatible nanopolymer with entitle poly arginine-graphene quantum dots-chitosan (PARG-GQDs-CS) as a novel strategy for surface modification of glassy carbon surface and preparation of a new interface for measurement of malondialdehyde (MDA) in exhaled breath condensate. Electrochemical deposition, as a well-controlled synthesis procedure, has been used for subsequently layer-by-layer preparation of GQDs-CS nanostructures on a PARG prepolymerized on the surface of glassy carbon electrode using cyclic voltammetry techniques in the regime of -1.5 to 2 V. The modified electrode appeared as an effective electroactivity for detection of MDA by using cyclic voltammetry, linear sweep voltammetry, and differential pulse voltammetry. The prepared modified electrode demonstrated a noticeably good activity for electrooxidation of MDA than PARG. Enhancement of peak currents is ascribed to the fast heterogeneous electron transfer kinetics that arise from the synergistic coupling between the excellent properties of PARG and semiconducting polymer, GQDs as high density of edge plane sites and subtle electronic characteristics and unique properties of CS such as excellent film-forming ability, high permeability, good adhesion, nontoxicity, cheapness, and a susceptibility to chemical modification. The prepared sensor showed 1 oxidation processes for MDA at potentials about 1 V with a low limit of quantification 5.94 nM. Finally, application of new sensor for determination of MDA in exhaled breath condensate was suited. In general, the simultaneous attachment of GQDs and CS to structure of poly amino acids provides new opportunities within the personal healthcare., (Copyright © 2018 John Wiley & Sons, Ltd.)