ABSTRACT
This work describes an environmental-friendly preparation of ZnO nanoparticles using aqueous oat extract. The advanced electrochemical and optical features of green synthesized ZnONPs displayed excellent antibacterial activity and exhibited an important role in pharmaceutical determinations. The formation of nanoscale ZnO was confirmed using various spectroscopic and microscopic investigations. The formed nanoparticles were found to be around 100 nm. The as-prepared ZnONPs were monitored for their antibacterial potential against different bacterial strains. The inhibition zones for ZnONPs were found as Escherichia coli (16 mm), Pseudomonas aeruginosa (17 mm), Staphylococcus aureus (12 mm) and Bacillus subtilis (11 mm) using a 30-µg mL-1 sample concentration. In addition, ZnONPs exhibited significant antioxidant effects, from 58 to 67%, with an average IC50 value of 0.88 ± 0.03 scavenging activity and from 53 to 71% (IC50 value of 0.73 ± 0.05) versus the scavenging free radicals DPPH and ABTS, respectively. The photocatalytic potential of ZnONPs for Rhodamine B dye degradation under UV irradiation was calculated. The photodegradation process was carried out as a function of time-dependent and complete degradation (nearly 98%), with color removal after 120 min. Conclusively, the synthesized ZnONPs using oat biomass might provide a great promise in the future for biomedical applications.
Subject(s)
Staphylococcus aureusABSTRACT
In this study, two metal oxide nanoparticles NiO and MnO2 were synthesized from green sources Mentha spicata (M. spicata) extract and Malus domestica (M. domestica) peel extract, respectively. The optical and physical properties of the synthesized nanoparticles were characterized using spectroscopic and microscopic techniques. Simple, precise, and new spectrophotometric probes were suggested for the determination of three cephalosporin antibiotics, including levofloxacin (LVX), cephalexin (CPX), and cefotaxime sodium (CTX) in their pure form and commercial products. The spectrophotometric detection of the selected drugs is based on the catalytic enhancement of NiO and MnO2 nanoparticles (NPs) due to their unique optical properties. Linear relationships with main correlation coefficients 0.999 were obtained at 0.1-20, 1.0-80, and 0.001-100 µg mL-1 for the three drugs in the presence of NiONPs, whereas 0.01-60, 0.1-160, and 0.01-80 µg mL-1 were obtained in the presence of MnO2NPs at absorption wavelengths 290, 262, and 235 nm for LVX, CPX and CTX, respectively. The analytical methods were validated and successfully used for determination of the instigated drugs in their bulk and commercial dosage forms.
ABSTRACT
The advanced and high-functional activities of magnesium oxide and copper oxide nanoparticles encourage the extensive use of these metal oxides as remarkable electroactive materials in electrochemical and sensing detections. The current study described a comparative sensing activity and selectivity of modified coated wire membrane sensors enriched with magnesium oxide and copper oxide nanoparticles for quantifying the breast cancer medication letrozole (LTZ) in its pharmaceutical form and human plasma. The fabricated sensors were based on the incorporation of LTZ with phosphomolybdic acid (PMA) to form the electroactive complex letrozole-phosphomolybate (LTZ-PM) in the presence of o-nitrophenyloctyl ether (o-NPOE) as a solvent mediator. Under optimum conditions, the modified sensors LTZ-PM-MgONPs and LTZ-PM-CuONPs demonstrated linear relationships of 1.0 × 10-8-1.0 × 10-2 and 1.0 × 10-10-1.0 × 10-2 mol L-1, respectively. Least square equations were calculated as EmV = (56.4 ± 0.7) log [LTZ] + 569.6 and EmV = (58.7 ± 0.3) log [LTZ] + 692.6 for LTZ-PM-MgONPs and LTZ-PM-CuONPs, respectively. The conventional type LTZ-PM showed a potential response EmV = (53.3 ± 0.5) log [LTZ] + 451.4 over concentration range of 1.0 × 10-6-1.0 × 10-2 mol L-1. The suggested sensors were successfully used to determine LTZ in pharmaceutical formulations and biosamples. Method validation ensured the suitability of the suggested potentiometric sensors.
ABSTRACT
The rapid detection of lung cancer in early stages using the antigen cytokeratin-19 fragment (CYFRA 21-1) as a tumor marker in human serum plays an important role in the survival of patients and taking a fast surgical reaction. This study aimed to employ the green synthesized carbon quantum dots conjugated zinc oxide nanocomposite as a highly sensitive fluorescence immunosensing solution for fast determination of CYFRA 21-1 antigen in human serum. The suggested method was conducted by applying a hydrothermal method to prepare carbon quantum dots using Citrus lemon pericarp. The formed carbon quantum dots were used in the reduction and stabilization of zinc acetate to synthesize carbon quantum dots-zinc oxide nanocomposite. To form a sandwich capping antibody-antigen-antibody immunosensing system, a CYFRA 21-1 antigen was trapped by immobilizing a non-conjugated monoclonal antibody BM 19.21 on the surface of carbon quantum dots-zinc oxide nanocomposite and another monoclonal antibody KS 19.1, which was coated on the microtiter well surface. This system has a tunable fluorescence feature recorded at excitation and emission of λex = 470 and λem = 520 nm, respectively. The suggested nanocomposite fluorescence immunosensing system displayed a linear relationship of 0.01-100 ng mL-1 with a limit of detection of 0.008 ng mL-1. The suggested immunosensing system based on carbon quantum dots-zinc oxide nanocomposite provides a promising approach for rapid diagnoses of lung cancer by detecting CYFRA 21-1 in human serum.
ABSTRACT
The clinical detection of carbohydrate antigen 19-9 (CA 19-9), a tumor marker in biological samples, improves and facilitates the rapid screening and diagnosis of pancreatic cancer. A simple, low cost, fast, and green synthesis method to prepare a viable carbon quantum dots/gold (CQDs/Au) nanocomposite fluorescence immunosensing solution for the detection of CA 19-9 was reported. The present method is conducted by preparing glucose-derived CQDs using a microwave-assisted method. CQDs were employed as reducing and stabilizing agents for the preparation of a CQDs/Au nanocomposite. The immobilized anti-CA 19-9-labeled horseradish peroxidase enzyme (Ab-HRP) was anchored to the surface of a CQDs/Au nanocomposite by a peptide interaction between the carboxylic and amine active groups. The CA 19-9 antigen was trapped by another monoclonal antibody that was coated on the surface of microtiter wells. The formed sandwich capping antibody-antigen-antibody enzyme complex had tunable fluorescence properties that were detected under excitation and emission wavelengths of 420 and 530 nm. The increase in fluorescence intensities of the immunoassay sensing solution was proportional to the CA 19-9 antigen concentration in the linear range of 0.01-350 U mL-1 and had a lower detection limit of 0.007 U mL-1. The proposed CQDs/Au nanocomposite immunoassay method provides a promising tool for detecting CA 19-9 in human serum.
Subject(s)
Biomarkers, Tumor/blood , CA-19-9 Antigen/blood , Gold/chemistry , Molecular Diagnostic Techniques/methods , Nanocomposites/chemistry , Quantum Dots/chemistry , Carbon/chemistry , Fluorescent Antibody Technique/methods , Humans , Nanocomposites/adverse effectsABSTRACT
The present article introduces a new approach to fabricate carbon paste sensors, including carbon paste, modified carbon paste inclusion ß-cyclodextrin, and carbon nanotubes for the quantification of dorzolamide hydrochloride (DRZ). This study is mainly based on the construction of three different carbon paste sensors by the incorporation of DRZ with phosphotungstic acid (PTA) to form dorzolamide-phosphotungstate (DRZ-PT) as an electroactive material in the presence of the solvent mediator ortho-nitrophenyloctyl ether (o-NPOE). The fabricated conventional carbon paste sensor (sensor I), as well as the other modified carbon paste sensors using ß-cyclodextrin (sensor II) and carbon nanotubes (sensor III), have been investigated. The sensors displayed Nernstian responses of 55.4 ± 0.6, 56.4 ± 0.4 and 58.1 ± 0.2 mV·decade-1 over concentration ranges of 1.0 × 10-5-1.0 × 10-2, 1.0 × 10-6-1.0 × 10-2, and 5.0 × 10-8-1.0 × 10-2 mol·L-1 with lower detection limits of 5.0 × 10-6, 5.0 × 10-7, and 2.5 × 10-9 mol·L-1 for sensors I, II, and III, respectively. The critical performance of the developed sensors was checked with respect to the effect of various parameters, including pH, selectivity, response time, linear concentration relationship, lifespan, etc. Method validation was applied according to the international conference on harmonisation of technical requirements for registration of pharmaceuticals for human use ICH guidelines. The developed sensors were employed for the determination of DRZ in its bulk and dosage forms, as well as bio-samples. The observed data were statistically analyzed and compared with those obtained from other published methods.
