Visual monitoring and optical recognition of digoxin by functionalized AuNPs and triangular AgNPs as efficient optical nano-probes.

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.

Sensitive recognition of ractopamine using GQDs-DPA as organic fluorescent probe.

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.

Providing multicolor plasmonic patterns with graphene quantum dots functionalized d-penicillamine for visual recognition of V(V), Cu (II), and Fe(III): Colorimetric fingerprints of GQDs-DPA for discriminating ions in human urine samples.

In this study, a novel fluorescent probe (graphene quantum dots functionalized d-penicillamine [GQDs-DPA]) was developed for the selective identification of Cu2+ , V5+ , and Fe3+ among 26 types of metal ions, which considerably quench the fluorescence intensity of GQD. So, GQDs-DPA was applied as a simple fluorescent probe for facile metal ions recognition in standard solution. The proposed DPA-GQD supported amino acids respond to Cu2+ , V5+ , 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), V(V), and Fe(III). Moreover, a microfluidic paper-based device (µPAD) was fabricated through a facile and cost-effective protocol. Cu2+ , V5+ , and Fe3+ can be selectively recognized by GQDs-DPA using µPAD by naked eye. Also, GQDs-DPA exhibits a linear response for the detection of ions in concentrations ranging from 0.01 to 1 ppm, with a low limit of quantification of 0.01 ppm in standards samples. The boosted color uniformity, low instrumental needs of the stamp, and disposability of µPADs enable the application of the proposed device for commercial applications in environmental science and technology.

A novel optical probe based on d-penicillamine-functionalized graphene quantum dots: Preparation and application as signal amplification element to minoring of ions in human biofluid.

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.

Spectrophotometric study of ketoconazole binding with citrate capped silver nanoparticles and its monitoring in human plasma samples.

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.

Biomedical applications of nanoflares: Targeted intracellular fluorescence probes.

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.

Dengue virus: a review on advances in detection and trends - from conventional methods to novel biosensors.

Dengue virus is an important arbovirus infection which transmitted by the Aedes female mosquitoes. The attempt to control and early detection of this infection is a global public health issue at present. Because of the clinical importance of its detection, the main focus of this review is on all of the methods that can offer the new diagnosis strategies. The advantages and disadvantages of reported methods have been discussed comprehensively from different aspects like biomarkers type, sensitivity, accuracy, rate of detection, possibility of commercialization, availability, limit of detection, linear range, simplicity, mechanism of detection, and ability of usage for clinical applications. The optical, electrochemical, microfluidic, enzyme linked immunosorbent assay (ELISA), and smartphone-based biosensors are the main approaches which developed for detection of different biomarkers and serotypes of Dengue virus. Future efforts in miniaturization of these methods open the horizons for development of commercial biosensors for early-diagnosis of Dengue virus infection. Graphical abstract Transmission of Dengue virus by the biting of an Aedes aegypti mosquito, the symptoms of Dengue hemorrhagic fever and the structure of Dengue virus and application of biosensors for its detection.

Formation of sparsely tethered bilayer lipid membrane on a biodegradable self-assembled monolayer of poly(lactic acid).

The utilization of biomimetic membranes supported by advanced self-assembled monolayers is gaining attraction as a promising sensing tool. Biomimetic membranes offer exceptional biocompatibility and adsorption capacity upon degradation, transcending their role as mere research instruments to open new avenues in biosensing. This study focused on anchoring a sparsely tethered bilayer lipid membrane onto a self-assembled monolayer composed of a biodegradable polymer, functionalized with poly(ethylene glycol)-cholesterol moieties, for lipid membrane integration. Real-time monitoring via quartz crystal microbalance, coupled with characterization using surface-enhanced infrared absorption spectroscopy and electrochemical impedance spectroscopy, provided comprehensive insights into each manufacturing phase. The resulting lipid layer, along with transmembrane pores formed by gramicidin A, exhibited robust stability. Electrochemical impedance spectroscopy analysis confirmed membrane integrity, successful pore formation, and consistent channel density. Notably, gramicidin A demonstrated sustained functionality as an ion channel upon reconstitution, with its functionality being effectively blocked and inhibited in the presence of calcium ions. These findings mark significant strides in developing intricate biodegradable nanomaterials with promising applications in biomedicine.

Digoxin as a glycosylated steroid-like therapeutic drug: Recent advances in the clinical pharmacology and bioassays of pharmaceutical compounds.

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.

DNA based biosensing of Acinetobacter baumannii using nanoparticles aggregation method.

Acinetobacter baumannii is the main cause of nosocomial infections in blood, urinary tract, wounds and in lungs leading to pneumonia. Apart from its strong predilection to be the cause of serious illnesses in intensive care units. Herein, we present a specific and sensitive approach for the monitoring of Acinetobacter baumannii genome based on citrate capped silver nanoparticles (Cit-AgNPs) using spectroscopic methods. In this study, (5' SH-TTG TGA ACT ATT TAC GTC AGC ATG C3') sequence was used as a probe DNA (pDNA) of Acinetobacter baumannii. Then, complementary DNA (cDNA) was used for hybridization. After the hybridization of pDNA with cDNA, target DNA (5' GCA TGC TGA CGT AAA TAGTTC ACA A 3') was recognized and detected using turn-on fluorescence bioassay. After the hybridization of pDNA with cDNA, the target DNA was successfully measured in optimum time of 2 min by spectrophotometric techniques. Moreover, the selectivity of designed bioassay was evaluated in the presence of two mismatch sequences and excellent differentiation was obtained. 1 Zepto-molar (zM) of low limit of quantification (LLOQ) was achieved by this genosensor. The present study paved the way for quick (2 min) and accurate detection of Acinetobacter baumannii, which can be a good alternative to the traditional methods. Current study proposed a novel and significant diagnostic test towards Acinetobacter baumannii detection based on silver nanoparticles aggregation which has the capability of being a good alternative to the traditional methods. Moreover, the proposed genosensor successfully could be applied for the detection of other pathogens.

An innovative genosensor for the monitoring of Leishmania spp sequence using binding of pDNA to cDNA based on Cit-AgNPs.

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.

Revolution in biomedicine using emerging of picomaterials: A breakthrough on the future of medical diagnosis and therapy.

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.

Carbon based nanomaterials for tissue engineering of bone: Building new bone on small black scaffolds: A review.

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.