103 research outputs found
Recent advances in developing optical and electrochemical sensors for analysis of methamphetamine: A review
Recognition of misused stimulant drugs has always been a hot topic from a medical and judicial perspective. Methamphetamine (MAMP) is an addictive and illegal drug that profoundly affects the central nervous system. Like other illicit drugs, the detection of MAMP in biological and street samples is vital for several organizations such as forensic medicine, anti-drug headquarters and diagnostic clinics. By emerging nanotechnology and exploiting nanomaterials in sensing applications, a great deal of attention has been given to the design of analytical sensors in MAMP tracing. For the first time, this study has briefly reviewed all the optical and electrochemical sensors in MAMP detection from earlier so far. How various receptors with engineering nanomaterials allow developing novel approaches to measure MAMP have been studied. Fundamental concepts related to optical and electrochemical recognition assays in which nanomaterials have been used and relevant MAMP sensing applications have been comprehensively covered. Challenges, opportunities and future outlooks of this field have also been discussed at the end. (C) 2021 Elsevier Ltd. All rights reserved
Sonochemical synthesis of ErVO4/MnWO4 heterostructures: Application as a novel nanostructured surface for electrochemical determination of tyrosine in biological samples
Present strategy introduces a novel method established for the synthesis of spherical shape ErVO4/MnWO4 heterostructures by a sonochemical method. This heterostructures with optima morphology can be synthesized by changing power and time ultrasound irradiation without any capping agent. BET analysis revealed that ErVO4/MnWO4 prepared in the presence of ultrasonic procedure has 75 times specific surface area as much as that of those was produced in the absence of ultrasonic rays. A variety of analyses (i.e., BET, XRD, TEM, EDS, FT-IR, and SEM) were applied for characterization of the ErVO4/MnWO4. Next, a selective and sensitive nanostructured sensor based on ErVO4/MnWO4 nanocomposite modified carbon paste electrode (ErVO4/MnWO4/CPE) was constructed for electrochemical detection of tyrosine (Tyr). The electrochemical characterizations were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Compared with the unmodified CPE, the oxidation peak current was significantly enhanced for Tyr. The impact of effective parameters on voltammetric response of Tyr was analyzed with design of experiments (DOE) and response surface methodology (RSM). Under the optimized conditions, the oxidation peak current of Tyr was linear over a range of 0.08�400.0 μM with a detection limit of 7.7 nM. Finally, the usage of the proposed method was confirmed by the recovery tests of Tyr in biological samples. © 201
Electrochemical determination of the antipsychotic medication clozapine by a carbon paste electrode modified with a nanostructure prepared from titania nanoparticles and copper oxide
A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable sensitive voltammetric determination of the drug clozapine (CLZ). The sensor was characterized by various techniques and some key parameters were optimized. Under the optimum conditions and at a working potential of 0.6 V (vs. Ag/AgCl), the modified CPE has two linear response ranges, one from 30 pmol L�1 to 4 nmol L�1 of CLZ, the other from 4 nmol L�1 to 10 μmol L�1. The detection limit is as low as 9 pM. The transfer coefficient (α) and catalytic rate constant (kcat) were calculated and the reliability of the sensor was estimated for CLZ sensing in real samples where it gave satisfactory results. Figure not available: see fulltext.. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature
Chemical sensors based on polymer composites with carbon nanotubes and graphene: the role of the polymer
Simultaneous voltammetric sensing of acetaminophen, epinephrine and melatonin using a carbon paste electrode modified with zinc ferrite nanoparticles
A highly selective electrochemical sensor was fabricated based on a modified carbon paste electrode with zinc ferrite nanoparticles (ZnFe2O4 NPs). The nanocomposite has attractive properties such as high surface-to-volume ratio and good electrocatalytic activity towards the drugs acetaminophen (AC), epinephrine (EP), and melatonin (MT), best at working voltages of 0.35, 0.09 and 0.55 V (vs. Ag/AgCl), respectively. The linear ranges (and detection limits) are 6.5-135 (0.4) mu mol L-1 for AC, 5-100 (0.7) mu mol L-1 for EP, and 6.5-145 (3) mu mol L-1 for MT
Introducing a novel nanocomposite consisting of nitrogen-doped carbon nano-onions and gold nanoparticles for the electrochemical sensor to measure acetaminophen
In the present study, gold nanoparticles and nitrogen-doped carbon nano-onions (AuNP/NCNO) in a nanocomposite-based sensor were reported for the electrochemical detection of acetaminophen (APAP). The NCNOs from the fullerene family were prepared using a simple and cost-effective method using aminated nanodiamonds (AM-ND) as a substrate. Nitrogen atoms were introduced into CNO cages during the preparation of these nanostructures by annealing AM-NDs under an inert helium atmosphere and reduced pressure. AuNPs were synthesized using a straightforward method. The nanocomposite profoundly enhanced the active surface area of the glassy carbon electrode and amplified the electron transfer rate. Accordingly, electrocatalysis of the APAP was achieved at the modified electrode surface at 0.38 V vs. Ag/AgCl. Under the optimal conditions, the sensor displayed a linear response for APAP detection ranging from 25 nM to 35 mu M with a limit of detection (LOD) of 9 nM. Potentially interfering drugs, such as ascorbic acid and dopamine, with 5-fold higher concentrations did not interfere with APAP detection. The feasibility of the sensor for APAP detection in tablet and serum samples was successfully evaluated. The qualities of this sensor, including its rapid-response, sensitivity and ease of use, maybe beneficial for potential applications in detecting other drugs
Applicability of a Green Nanocomposite Consisted of Spongin Decorated Cu2WO4(OH)2 and AgNPs as a High-Performance Aptasensing Platform in Staphylococcus aureus Detection
This study reports the synthesis of a nanocomposite consisting of spongin and its applicability in the development of an aptasensing platform with high performance. The spongin was carefully extracted from a marine sponge and decorated with copper tungsten oxide hydroxide. The resulting spongin-copper tungsten oxide hydroxide was functionalized by silver nanoparticles and utilized in electrochemical aptasensor fabrication. The nanocomposite covered on a glassy carbon electrode surface amplified the electron transfer and increased active electrochemical sites. The aptasensor was fabricated by loading of thiolated aptamer on the embedded surface via thiol-AgNPs linkage. The applicability of the aptasensor was tested in detecting the Staphylococcus aureus bacterium as one of the five most common causes of nosocomial infectious diseases. The aptasensor measured S. aureus under a linear concentration range of 10–108 colony-forming units per milliliter and a limit of quantification and detection of 12 and 1 colony-forming unit per milliliter, respectively. The highly selective diagnosis of S. aureus in the presence of some common bacterial strains was satisfactorily evaluated. The acceptable results of the human serum analysis as the real sample may be promising in the bacteria tracking in clinical samples underlying the green chemistry principle
A nanocomposite prepared from reduced graphene oxide, gold nanoparticles and poly(2-amino-5-mercapto-1,3,4-thiadiazole) for use in an electrochemical sensor for doxorubicin
A nanocomposite was prepared with reduced graphene oxide, gold nanoparticles and an electropolymerized film made from 2-amino-5-mercapto-1,3,4-thiadiazole. An electrochemical sensor for doxorubicin (DOX) was constructed by modifying a glassy carbon electrode (GCE) with the nanocomposite. The modified GCE was studied by electrochemical techniques which showed it to enable highly sensitive sensing of DOX. Response (typically measured at a typical working potential of -0.56 V vs. Ag/AgCl) is linear in the 30 pM to 30 nM and 30 nM to 30 muM DOX concentration ranges, with a limit of detection (LOD) of 9 pM (at an S/N ratio of 3). The method was applied to the determination of DOX in serum and gave recoveries that ranged between 92 and 108. Graphical abstract A combination of materials consisting of reduced graphene oxide (rGO), gold nanoparticles (AuNPs) and an electropolymerized film of 2-amino-5-mercapto-1,3,4-thiadiazole (poly-AMT, PAMT) is described. The nanocomposite was placed on a glassy carbon elkectrode (GCE) in order to fabricate an electrochemical sensor for doxorubicin (DOX)
Fabrication of an ultrasensitive ibuprofen nanoaptasensor based on covalent attachment of aptamer to electrochemically deposited gold-nanoparticles on glassy carbon electrode
Ultra-sensitive detection of ibuprofen (IBP) by electrochemical aptasensor using the dendrimer-quantum dot (Den-QD) bioconjugate as an immobilization platform with special features
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