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In this study, a novel fluorescent probe (graphene quantum dots functionalized d-penicillamine [GQDs-DPA]) was developed for the selective identification of Cu

In this study, we presented elective, sensitive, and rapid UV-Vis spectrophotometry and calorimetric assay for the recognition of digoxin. Therefore, cysteamine-gold nanoparticles (Cys A-AuNPs) in the presence of cysteine acid amine and Silver nanoparticles in the presence of tetramethyl benzidine and hydrogen peroxide (AgNPs-TMB [3,3',5,5'-tetramethylbenzidine]-H2 O2 ) were synthesized and utilized as the desired probe. Finally, color variation of probes was observed in the absence and presence of digoxin. Obtained results indicate that the color of Cys A-AuNPs changed from dark pink to light in the absence and the presence of digoxin, respectively. Also, the color of AgNPs-TMB-H2 O2 changed from dark blue to light blue, in the absence and the presence of digoxin, respectively. Moreover, UV-Vis spectroscopies results indicate digoxin with a low limit of quantification of 0.125 ppm in human plasma samples which linear range was 0.125 to 11 ppm.

A novel spectrofluorimetric sensing platform was designed for Ractopamine measurement in aqueous and plasma samples. d-penicillamine functionalized graphene quantum dots (DPA-GQDs) was utilized as a fluorescence probe, which was synthesized through the pyrolysis of citric acid in the presence of DPA. This one-pot down-top strategy causes to high-yield controllable synthesis method. The reaction time and probe concentration were optimized. Then, the fluorescence intensity of aqueous samples containing different Ractopamine concentrations and 500 ppm DPA-GQDs were measured at 25°C with an excitation wavelength of 274 nm. The sensing platform was also applied to detect Ractopamine in untreated plasma samples. The fluorescence spectroscopy technique responses indicated a linear relationship between the peak fluorescence intensity and ractopamine concentration in the range of 0.25-15 ppm with low limit of quantification of 0.25 ppm was for aqueous and plasma samples, respectively.

Leishmaniasis considered as the most crucial epidemic-prone diseases according to the World Health Organization. Early diagnoses and therapy of Leishmania infection is a great challenge since, it has no symptom and is resistance to drugs. Therefore, there is an urgent need for sensitive and precise detection of this pathogen. In this study, a new method was developed for optical biosensing of Leishmania spp sequence based on hybridization of Citrate capped Ag nanoparticles bonded to specific single stranded DNA probe of Leishmania spp. Aggregation of the Citrate capped Ag nanoparticles in the existence or lack of a cDNA sequence of Leishmania, cause eye catching and considerable significant alter in the UV–vis. The obtained low limit of quantification (LLOQ) of was achieved as 1ZM. Based on experimental results in optimum conditions, quick bioanalysis of Leishmania spp sequence was performed (2 min). So, this probe can be used for the clinical diagnosis of this pathogen and infection disease., Analytical chemistry; Nanotechnology, Nanostructure; Affinity binding; Leishmaniasis; Spectrophotometer; Spectrofluorimetric; Biosensing

Ketoconazole or Nizoral is an antifungal medication used to treat various type of fungal infections. It has been reported that this antifungal agent is able to induce a variety of heart function side effects, such as long-QT syndrome, and ventricular arrhythmias. Hence, prescribing, identifying and controlling the side effects of medications such as ketoconazole is essential for human safety. In this study, a distinct and fast colorimetric probe based on citrate capped silver nanoparticles (Cit-AgNPs) was introduced for determination of trace amounts of ketoconazole. Cit-AgNPs were synthesized trough a novel method and applied for the quantification of ketoconazole in human plasma samples. Ultraviolet-visible spectroscopy, transmission electron microcopy, dynamic light scattering, and energy dispersive X-ray spectroscopy analysis, have been utilized for characterization of Cit-AgNPs. It was revealed that in the presence of ketoconazole, the absorption intensity of Cit-AgNPs was decreased by increasing the ketoconazole concentration. Moreover, this reaction is accompanied by a color change from shiny yellow to brown/red in acidic pH. Under acidic pH and optimum condition, the calibration graph of the assay was linear in the range of 0.1 to 0.8 μM. According to the obtained results Cit-AgNPs can be used as a novel probe for the sensitive and specific detection and determination of similar drugs in clinical samples. Also, this method open a new way to biomedical analyses of pharmaceutical samples which is necessary in TDM.

In this study, d-penicillamine-functionalized graphene quantum dots (DPA-GQD) has been synthesized, which significantly increases the fluorescence intensity of GQD. We used this simple fluorescent probe for metal ions detection in human plasma samples. Designed DPA-GQD respond to Hg2+ , Cu2+ , Au2+ , Ag+ , Co2+ , Zn2+ , and Pb2+ with high sensitivity. The fluorescence intensity of this probe decreased significantly in the presence of metal ions such as, Hg2+ , Cu2+ , Au2+ , Ag+ , Co2+ , Zn2+ , and Pb2+ . In this work, a promising probe for ions monitoring was introduced. Moreover, DPA-GQD probe has been tested in plasma samples. The functionalized DPA-GQDs exhibits great promise as an alternative to previous fluorescent probes for bio-labeling, sensing, and other biomedical applications in aqueous solution.

Digoxin is cardiac glycosylated steroid like drug which is the fifth most commonly prescribed in US. Since the health of human population is largely determined by pharmacy they utilized, toxicity and side effects of pharmaceutics can put the safety of people in jeopardy and lead to some devastating impacts. Therefore, it is essential to detect and monitor small molecules like digoxin more meticulously. Although digoxin has positive inotropic and batmotropic impact on heart muscle, it has also negative chronotropic and dromotropic effect. The prescription dose of this drug is 1-2 ng/ml and more than 2.8 ng/ml of this medication cause toxicity. Hence, there is small variation between therapeutic and toxic dosage of digoxin. Abundant conventional methods have been introduced for digoxin monitoring such Liquid chromatography (LC), LC-MS, HPLC. However, they suffer expensive equipment, long lasting procedure and high limit of detection. Hence, various advance immunosorbent, biosensors and aptasensors have been introduced. The purpose of this review is limited to pointing convention methods drawbacks and introducing novel digoxin enzyme-linked or non-enzymatic immunosorbent assays, and biosensors paying special attention to their basic strategies and detection abilities. Future trends in Bio and immune sensors used for onset monitoring and detection of digoxin are also highlighted.

Botulinum toxin is a neurotoxic protein which produced from Clostridium botulinum and related species and it block acetylcholine release from presynaptic nerve terminals at the neuromuscular junctions. This toxin is life threatening for millions of people and growing menace to society since causing human botulism. Enzymatic activity of Botulinum neurotoxin within the cell made it hazardous and lead to flaccid paralysis. However, there isn't any reliable and precise remedy for this toxin. Therefore, there is an urgent need for early detection of this toxin in a fast and meticulous way with a robust and cost-effective relationship for real-time monitoring of Botulinum neurotoxin. Several biosensors have been designed and commercialized for this purpose. In this overview, novel biosensing methods; such as various optical and electrochemical ones proposed for detection of Botulinum neurotoxin have been summarized. Furthermore, attention has been focused on the main concepts, applications, and examples that have been achieved up to diagnostics of botulism.

Cancer is a real menace to all societies globally since it is the leading cause of premature mortality in men and women. The incidence of malignancies is enhancing as a result of plenty factors. Physically and economically concerns that occur in cancers patients cannot be neglected. However, current diagnostic methods and cure duration do not fulfill patients requirements. Therefore, it is essential to detect and diagnose cancer biomarkers as soon as possible and overcome the current burdens. Novel aptasensors is emerging as one of the most promising strategies for early recognition of cancer. Aptamers an artificial DNA or RNA sequences, possess plenty of merits such as easy production, modification of their structure, lower immunogenicity, and high affinity to target that pave the way for early detection of cancer biomarkers. This review attempts to list novel and advanced investigation progress of aptamers in biosensor platforms for diagnosing of malignancies.

This study reports the synthesis of functional graphene quantum dots (GQDs) through the thermal pyrolysis of D-penicillamine (DPA) and citric acid towards water treatment. For the first time, a novel type of highly fluorescent probe for selective Cu2+ detection among 26 types of metal ions which considerably enhance the fluorescence intensity of GQD. Furthermore, the recognition effects can be strengthen addition of amino acids owing to raise the electron density of the system and boos the accumulation profile of the sensing molecules. This simple fluorescent probe was applied for facile metal ions recognition in human urine samples, as well as environmental fluids. The proposed DPA-GQDs supported amino acids respond to Cu2+, Hg2+, and Fe3+, with high sensitivity. The intensity of the fluorescence histogram of this probe significantly diminished in exposure to metal ions such as, Cu(II), Hg(II), and Fe(III). Moreover, in our work, microfluidic paper-based (µPADs) was fabricated through a facile and a cost-effective method. Cu2+ can selectively be recognized by GQD-DPA on the paper-based sensors by naked-eye. The functionalized DPA-GQDs is an excellent alternative to previously reported fluorescent probes for sensing, bio-labeling, and other biological usages in aqueous solution. Its nitrogen and oxygen-rich groups can coordinate with Cu2+ and cause to an apparent fluorescence quenching by the non-radiative electron-transmission. The technique presented in this paper is economical and simple in design, and provides a "mix-and-sense" protocol with no need to chemical- or dye-modifications. Our proposed Cu2+ sensing probe exhibits linear response in the concentrations ranging from 0.001 ppm to 5 ppm, with a lower limit of quantitation (LLOQ) of 0.1 ppm in both environmental fluids, and human urine samples. The enhanced color uniformity, the low instrumental needs of the stamp, and disposability of μPADs enable the application of the suggested paper-based device for the commercial diagnostics biosensor.

In this study, an innovative methods was proposed for the synthesis of cysteamine@gold nanoparticle (CysA@AuNPs) using one step protocol. Also, application of CysA@AuNPs for the sensitive recognition of Hg (II) and Cu (II) in aqueous media was investigated using optical techniques. This research work explains the development of a lightweight stamp for manufacturing of a novel microfluidic paper-based analytical device (μPADs), as a simple colorimetric sensor for selective recognition of Hg2+ and Cu2+ within the other metal ions (Fe(III), Mn(II), Zr(IV), Ba(II), Mg(II), Sr(II), As(III), B(III), Al(III), V(III), K(I), Na(I), Mo(II), Co(II), Zn(II), Sn(II), Se(IV), Cr(III), Bi(III)) in aqueous, and human biofluids. CysA@AuNPs supported amino acids were used as the ion detection probs. The specific colorimetric response of Hg2+ and Cu2+ amongst the other ions through the innovative sensor allows naked-eye discrimination of the mercury and copper metal ions in this work with excellent selectivity in the presence of cysteine, and methionine. The results revealed our new strategy (μPADs) for the colorimetric recognition of mercury and copper ions, in both urine and aqueous samples, is selective, simple, fast, sensitive, quantitative, cost-effective, and eco-friendly, which can be detected by naked eye through color alternation with LLOQ of 0.001 ppm for Hg2+, and 0.02 ppm for Cu2+ with admirable stability. The low instrumental needs of the stamp, and disposability of μPADs enable the application of the suggested paper-based device for the commercial diagnostics biosensor.

Recent developments in the field of metal-organic frameworks (MOFs) have renewed the interests of scientists to bring about a major breakthrough in this field soon. These particles consist of ultra-highly porous and tremendous internal surface areas with extraordinary variabilities that make them highly potent compounds in nanomedicine. Moreover, low weight, large free volumes, and multiple functionalities of these particles have made them extremely attractive for various applications. Along with a critical role in the adsorption and separation of different analytes, they also have an immense role in the development of biosensor platforms that are expected to pave the way for accurate and sensitive detection of various analytes. Hence, this review intends to highlight recent advances on the core structural characteristics and physio-chemical features of MOFs and their functional applications in developing electrochemical, optical, and colorimetric MOF-based sensing and biosensing assays via different recognition elements. Moreover, the effects of various modification/fractionalization methods on the performance of MOFs, as well as challenges and problems in their clinical application are discussed. Furthermore, this paper attempts to divulge the main concepts and applications that have been accomplished to modify and apply MOFs in biosensing platforms in future.

Early detection of inflammatory mediators including C-reactive protein (CRP) is of great diagnostic importance in many human diseases. CRP elevates very fast in conditions such as tissue injuries, infections, cancers, and renal and cardiovascular diseases. Conventional techniques for detecting CRP are based on antigen–antibody, agglutination, and precipitation reactions. Newer methods based on immunoturbidimetry and immunonephelometry are also time-consuming and relatively expensive. For solving these problems, highly efficient techniques based on CRP-biosensors have been introduced. Here, our aim was to summarize the features of recent biosensors for detection of CRP in biological samples. These include electrochemical (voltammetric and impedimetric), optical (surface plasmon resonance, fluorescence and luminescence), field effect transistor (FET), and quartz crystal microbalance (QCM) biosensors which have been addressed in detail here.

Micro ribose nucleic acid (miRNA) recognition is of remarkable significance in the investigation of its functions as well as diagnosis of various diseases. The significance of miRNA itself is owing to the complex regulatory roles in several physiological processes and its close association with important diseases such as cardiovascular problems, diabetes, Alzheimer's disease and different kinds of cancers. On the other hand, there are numerous challenges to conquer in the recognition of miRNA, consisting of low abundance, varied concentration range, small size, prolonged extraction process from cells and sequence resemblances. Traditional approaches for miRNA recognition do not meet the present demands; therefore, several fast and effective strategies have been developed with a superior focus on specificity and sensitivity such as molecular beacon (MB) probes. These probes have been widely used for miRNA monitoring with high sensitivity both in living cells and in vitro. Compared to other systems, such as qRT-PCR, studies demonstrated that MB probes can be applied as effective equipment for assaying miRNAs by taking their advantages e.g. good specificity, short hybridization period, and easy operation. Therefore, this review highlights astonishing abilities and structure of MBs and their principle. Also, the use of atomic thickness nanomaterials such as quantum dots, molybdenum disulfide, and molybdenum carbide are introduced. Moreover, new advances in developing MB approaches that are able to trace miRNA in living cells and in vivo are discussed.

Graphical abstract, Highlights • Bone tissue engineering allows stem cells to form mechanically adequate new bone. • Nanomaterial scaffolds allow cell adhesion, growth, and differentiation. • Carbon nanomaterials have good properties as scaffolds for bone tissue engineering. • Includes graphene oxide, carbon nanotubes, fullerenes, carbon dots, and nanodiamond. • Biocompatibility, low toxicity, and a nano-patterned surface form ideal scaffold., Tissue engineering is a rapidly-growing approach to replace and repair damaged and defective tissues in the human body. Every year, a large number of people require bone replacements for skeletal defects caused by accident or disease that cannot heal on their own. In the last decades, tissue engineering of bone has attracted much attention from biomedical scientists in academic and commercial laboratories. A vast range of biocompatible advanced materials has been used to form scaffolds upon which new bone can form. Carbon nanomaterial-based scaffolds are a key example, with the advantages of being biologically compatible, mechanically stable, and commercially available. They show remarkable ability to affect bone tissue regeneration, efficient cell proliferation and osteogenic differentiation. Basically, scaffolds are templates for growth, proliferation, regeneration, adhesion, and differentiation processes of bone stem cells that play a truly critical role in bone tissue engineering. The appropriate scaffold should supply a microenvironment for bone cells that is most similar to natural bone in the human body. A variety of carbon nanomaterials, such as graphene oxide (GO), carbon nanotubes (CNTs), fullerenes, carbon dots (CDs), nanodiamonds and their derivatives that are able to act as scaffolds for bone tissue engineering, are covered in this review. Broadly, the ability of the family of carbon nanomaterial-based scaffolds and their critical role in bone tissue engineering research are discussed. The significant stimulating effects on cell growth, low cytotoxicity, efficient nutrient delivery in the scaffold microenvironment, suitable functionalized chemical structures to facilitate cell-cell communication, and improvement in cell spreading are the main advantages of carbon nanomaterial-based scaffolds for bone tissue engineering.

Mesoporous silica nanoparticles (MSNs) are an essential and inseparable part of scientific application in today's world. These materials garnered more attention, in biosensing, catalysis, bioimaging, energy storage, and disease diagnosis due to their privileged futures. The unique physiochemical properties have been made these nanomaterials an excellent candidate for drug delivery applications as well as electrochemical and optical biosensing. MSNs are able to encapsulate enormous materials in their structural pores and deliver those materials to target, more meticulously. Aptasensor is type of biosensors that use aptamer for increasing selectivity and sensitivity. These are capture by nanomaterials by covalent and non-covalent linking for many different purpose such as diagnosis and target therapy. The aim of this review is introducing the most recent research progress on aptasensors based on MSNs, including various optical and electrochemical aptasensors, their strategy, and procedure, limit of detection, as well as their advantages and limitation. Moreover, different types of aptasensors based on MSNs is highlighted in this review for targeting and treatment of cancer cells. Although encouraging and interesting investigations have been achieved in this filed, design and mass production and effective biological application of aptasensors and MSNs based aptasensors are still challenging.

Nanoflares are intracellular probes consisting of oligonucleotides immobilized on various nanoparticles that can recognize intracellular nucleic acids or other analytes, thus releasing a fluorescent reporter dye. Single-stranded DNA (ssDNA) complementary to mRNA for a target gene is constructed containing a 3'-thiol for binding to gold nanoparticles. The ssDNA "recognition sequence" is prehybridized to a shorter DNA complement containing a fluorescent dye that is quenched. The functionalized gold nanoparticles are easily taken up into cells. When the ssDNA recognizes its complementary target, the fluorescent dye is released inside the cells. Different intracellular targets can be detected by nanoflares, such as mRNAs coding for genes over-expressed in cancer (epithelial-mesenchymal transition, oncogenes, thymidine kinase, telomerase, etc.), intracellular levels of ATP, pH values and inorganic ions can also be measured. Advantages include high transfection efficiency, enzymatic stability, good optical properties, biocompatibility, high selectivity and specificity. Multiplexed assays and FRET-based systems have been designed.

Biomedicine is inseparable part of medicine that play vital role in modern medical progress. Bioimaging, smart drug delivery, safe cancer therapy and personalized medicine are some important properties of this science. Pico technology as a next frontier in a scientific filed will revolutionized the scientist world ubiquitously. Extraordinary abilities of pico-particles will overcome convention obstacles and reveal spectacular impact on various scientific fields as well as biomedicine. Fabrication of pico-scale particles and developing pico-technology will be a breakthrough in biomedicine. Graphene Quantum Dots (GQDs) with the particle size of 1–5 nm are highly potential particles with an ability of converting to small molecules. Therefore, we hypothesis emerging of pico-technology based on graphene quantum dots on the future research and development. Therefore, GQDs will be applied as advanced Pico-materials instead of nanomaterials in the future biomedicine and healthcare studies.