scholarly journals Novel Competitive Voltammetric Aptasensor Based on Electrospun Carbon Nanofibers-Gold Nanoparticles Modified Graphite Electrode for Salmonella enterica serovar Detection

2020 ◽  
Vol 11 (2) ◽  
pp. 8702-8715

Salmonella enterica is considered one of the most common bacterial agent causes of acute gastroenteritis and foodborne illness in humans worldwide. Antibiotic-resistant is considered as a major problem in Salmonella enterica Serovar. This study introduces a new simple and sensitive aptasensor based on chitosan (Chi)-electrospun carbon nanofibers (CNF) /gold nanoparticles (GNPs) decorated pencil graphite electrode (GE) as a novel platform for electrochemical detection of Salmonella enterica Serovar. A Salmonella-specific recognition aptamer ssDNA sequence was used in the development of this voltammetric biosensor. Electrochemical behaviors of electrodes; unmodified GE, CNF-Chi/GE, GNPs/CNF-Chi/GE, GNPs/CNF-Chi/GEs linked with the aptamer were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). After the optimization of experimental conditions (e.g., CNF concentration, pH, and incubation time), electrochemical detection of Salmonella was performed via differential pulse voltammetry (DPV) in methylene blue solution. The designed aptasensor exhibited a linear range of 10 to 105 (CFU/mL) with the limit of detection (LOD) 1.223 (Cfu/mL) for Salmonella. This aptasensor displayed excellent selectivity and remarkable sensitivity in terms of the detection of Salmonella enterica even in the real samples as compared to the polymerase chain reaction (PCR) technique. The constructed aptasensor is a highly sensitive sensor for the detection of Salmonella enterica and also can be tailored for various other targets.

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1334
Author(s):  
Mohammad Mehmandoust ◽  
Nevin Erk ◽  
Ceren Karaman ◽  
Fatemeh Karimi ◽  
Sadegh Salmanpour

The accurate and precise monitoring of epirubicin (EPR), one of the most widely used anticancer drugs, is significant for human and environmental health. In this context, we developed a highly sensitive electrochemical electrode for EPR detection based on nickel ferrite decorated with gold nanoparticles (Au@NiFe2O4) on the screen-printed electrode (SPE). Various spectral characteristic methods such as Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), energy-dispersive X-ray spectroscopy (EDX) and electrochemical impedance spectroscopy (EIS) were used to investigate the surface morphology and structure of the synthesized Au@NiFe2O4 nanocomposite. The novel decorated electrode exhibited a high electrocatalytic activity toward the electrooxidation of EPR, and a nanomolar limit of detection (5.3 nM) was estimated using differential pulse voltammetry (DPV) with linear concentration ranges from 0.01 to 0.7 and 0.7 to 3.6 µM. The stability, selectivity, repeatability reproducibility and reusability, with a very low electrode response detection limit, make it very appropriate for determining trace amounts of EPR in pharmaceutical and clinical preparations.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 929
Author(s):  
Amira Mahmoud ◽  
Mosaab Echabaane ◽  
Karim Omri ◽  
Julien Boudon ◽  
Lucien Saviot ◽  
...  

Copper-doped zinc oxide nanoparticles (NPs) CuxZn1−xO (x = 0, 0.01, 0.02, 0.03, and 0.04) were synthesized via a sol-gel process and used as an active electrode material to fabricate a non-enzymatic electrochemical sensor for the detection of glucose. Their structure, composition, and chemical properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) and Raman spectroscopies, and zeta potential measurements. The electrochemical characterization of the sensors was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Cu doping was shown to improve the electrocatalytic activity for the oxidation of glucose, which resulted from the accelerated electron transfer and greatly improved electrochemical conductivity. The experimental conditions for the detection of glucose were optimized: a linear dependence between the glucose concentration and current intensity was established in the range from 1 nM to 100 μM with a limit of detection of 0.7 nM. The proposed sensor exhibited high selectivity for glucose in the presence of various interfering species. The developed sensor was also successfully tested for the detection of glucose in human serum samples.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Syeda Aqsa Batool Bukhari ◽  
Habib Nasir ◽  
Lujun Pan ◽  
Mehroz Tasawar ◽  
Manzar Sohail ◽  
...  

AbstractNon-enzymatic electrochemical detection of catechol (CC) and hydroquinone (HQ), the xenobiotic pollutants, was carried out at the surface of novel carbon nanocoils/zinc-tetraphenylporphyrin (CNCs/Zn-TPP) nanocomposite supported on glassy carbon electrode. The synergistic effect of chemoresponsive activity of Zn-TPP and a large surface area and electron transfer ability of CNCs lead to efficient detection of CC and HQ. The nanocomposite was characterized by using FT-IR, UV/vis. spectrophotometer, SEM and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry, differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy were used for the electrochemical studies. CNCs/Zn-TPP/GCE nanosensor displayed a limit of detection (LOD), limit of quantification (LOQ) and sensitivity for catechol as 0.9 µM, 3.1 µM and 0.48 µA µM−1 cm−2, respectively in a concentration range of 25–1500 µM. Similarly, a linear trend in the concentration of hydroquinone detection was observed between 25 and 1500 µM with an LOD, LOQ and sensitivity of 1.5 µM, 5.1 µM and 0.35 µA µM−1 cm−2, respectively. DPV of binary mixture pictured well resolved peaks with anodic peak potential difference, ∆Epa(CC-HQ), of 110 mV showing efficient sensing of CC and HQ. The developed nanosensor exhibits stability for up to 30 days, better selectivity and good repeatability for eight measurements (4.5% for CC and 5.4% for HQ).


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3684 ◽  
Author(s):  
Yesong Gu ◽  
Po-Yuan Tseng ◽  
Xiang Bi ◽  
Jason Yang

The general clinical procedure for viral DNA detection or gene mutation diagnosis following polymerase chain reaction (PCR) often involves gel electrophoresis and DNA sequencing, which is usually time-consuming. In this study, we have proposed a facile strategy to construct a DNA biosensor, in which the platinum electrode was modified with a dual-film of electrochemically synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) resulting in immobilized gold nanoparticles, with the gold nanoparticles easily immobilized in a uniform distribution. The DNA probe labeled with a SH group was then assembled to the fabricated electrode and employed to capture the target DNA based on the complementary sequence. The hybridization efficiency was evaluated with differential pulse voltammetry (DPV) in the presence of daunorubicin hydrochloride. Our results demonstrated that the peak current in DPV exhibited a linear correlation the concentration of target DNA that was complementary to the probe DNA. Moreover, the electrode could be reused by heating denaturation and re-hybridization, which only brought slight signal decay. In addition, the addition of the oxidized form of nicotinamide adenine dinucleotide (NAD+) could dramatically enhance the sensitivity by more than 5.45-fold, and the limit-of-detection reached about 100 pM.


2019 ◽  
Vol Vol. 14, No.1 ◽  
pp. 5-14 ◽  
Author(s):  
Anastasiya Tkachenko ◽  
Mykyta Onizhuk ◽  
Oleg Tkachenko ◽  
Leliz T. Arenas ◽  
Edilson V. Benvenutt ◽  
...  

In the present study, an electrochemical sensor based on the electrode (SiMImCl/C) consisting of graphite and silica, grafted with 1-n-propyl-3-methylimidazolium chloride was used for ascorbic acid (AA) quantification in pharmaceuticals and food formulations. Cyclic voltammetry and electrochemical impedance spectroscopy were applied for electrochemical characterization of the SiMImCl/C electrode. The cyclic voltammetry study revealed that the oxidation of AA on this electrode is an irreversible process, realized by adsorption and diffusion limited step. The differential pulse voltammetry was applied to develop a procedure for the AA determination. The linear range was found to be 0.3–170 μmol L-1 and the limit of detection – 0.1 μmol L-1. The proposed SiMImCl/C electrode has long term stability and does not show electrochemical activity towards the analytes, which commonly coexist with AA. The sensor was successfully used for quantification of AA in food and pharmaceutical formulations.


2020 ◽  
Vol 20 (6) ◽  
pp. 3356-3360
Author(s):  
Hao Yong Yin ◽  
Yi Fan Zheng ◽  
Ling Wang

We report the formation of gold nanoparticles on indium tin oxide conducting glass (ITO) surface via electrodeposition method at room temperature. The prepared nano-Au electrodes has been fabricated for sensitive detection of Pb2+, and showed highly selective response toward Pb2+. The electrochemical detection of Pb2+ were determined by differential pulse stripping voltammetric (DPSV). The nano-Au electrochemical sensor could detect Pb2+ from 0.5 to 10 μM with detection limits of 0.06 μM (S/N= 3) and sensitivity of 0.27996 mA μM−1. The proposed sensor is simple, reliable, sensitive, selective, and low-cost, thus holds potential for practical application in Pb2+ detection.


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