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)

Effects of different wastewater treatment processes on occurrence and prevalence of antibiotic resistant bacteria and their resistance genes

This study aimed to explore the difference between hospital and municipal wastewater treatment processes regarding the reduction of antibiotic-resistant bacteria (ARB) and antibiotic resistant genes (ARGs). Samples were collected from raw and final effluent of four different wastewater treatment plants (WWTPs). ARB were evaluated by modified HPC method. Extraction and purification of DNA from the samples were conducted by Freeze-Thaw and DNA extraction kit. Real-time PCR (qPCR) was utilized to obtain the quantity of Sul1 and ErmB genes in the samples. For standard control in qPCR, was used plasmid containing each gene sequence. The average ARB concentration in the raw wastewater and effluent was 1.03�107-6.63�107 CFU/100mL. Quantitative range of the Sul1 and ErmB genes were obtained as 0-8.3�1010 Copies/100 mL and 9.29�105-9.64�109 Copies/100 mL, respectively. The results show that urban wastewaters play a more significant role than hospital wastewaters in the emission of sulfonamides and erythromycin-resistant bacteria and genes to the environment. Findings revealed that conventional wastewater treatment plants cannot be regarded as reliable barriers for the control of these agents. © 2020, Dorma Journals. All rights reserved

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 mu mol L-1. The detection limit is as low as 9 pM. The transfer coefficient (alpha) and catalytic rate constant (k(cat)) were calculated and the reliability of the sensor was estimated for CLZ sensing in real samples where it gave satisfactory results

A nanocomposite consisting of reduced graphene oxide and electropolymerized -cyclodextrin for voltammetric sensing of levofloxacin

A glassy carbon electrode (GCE) was modified with a nanocomposite prepared from polymerized -cyclodextrin (-CD) and reduced graphene oxide (rGO). The modified GCE is shown to enable the voltammetric determination of traces of levofloxacin (LEV) by various electrochemical techniques. Experimental factors affecting the results including the amount of the substrates in preparation of the nanocomposite, accumulation time, the scan rate and pH value of the electrolyte were optimized. The modified GCE, best operated at a working potential of 1.00V (vs. Ag/AgCl), has two linear response ranges, one for low LEV concentrations (100pmolL(-1) to 100nmolL(-1)), and one for higher LEV concentrations (100nmolL(-1) to 100molL(-1)). The limit of detection and sensitivity are calculated to be 30pmolL(-1) and 467.33nAmolL(-1)cm(-2), respectively. The modified GCE demonstrates a number of advantages such as high sensitivity and selectivity, low LOD, excellent reproducibility, high surface-to-volume ratio, and good electrocatalytic activity towards LEV. The sensor was successfully applied to the determination of LEV in spiked human serum samples