Voltammetric Behavior and Detection of DNA at Electrochemically Pretreated Glassy Carbon Electrode

Review of Electrochemical DNA Biosensors for Detecting Food Borne Pathogens

The vital importance of rapid and accurate detection of food borne pathogens has driven the development of biosensor to prevent food borne illness outbreaks. Electrochemical DNA biosensors offer such merits as rapid response, high sensitivity, low cost, and ease of use. This review covers the following three aspects: food borne pathogens and conventional detection methods, the design and fabrication of electrochemical DNA biosensors and several techniques for improving sensitivity of biosensors. We highlight the main bioreceptors and immobilizing methods on sensing interface, electrochemical techniques, electrochemical indicators, nanotechnology, and nucleic acid-based amplification. Finally, in view of the existing shortcomings of electrochemical DNA biosensors in the field of food borne pathogen detection, we also predict and prospect future research focuses from the following five aspects: specific bioreceptors (improving specificity), nanomaterials (enhancing sensitivity), microfluidic chip technology (realizing automate operation), paper-based biosensors (reducing detection cost), and smartphones or other mobile devices (simplifying signal reading devices).

Simultaneous determination of guanine and adenine in the presence of uric acid by a poly(para toluene sulfonic acid) mediated electrochemical sensor in alkaline medium

Simultaneous sensing of guanine and adenine in presence of uric acid in alkaline medium by polymer modified electrode.

A new electrochemical sensor for the simultaneous determination of guanine and adenine: using a NiAl-layered double hydroxide/graphene oxide-multi wall carbon nanotube modified glassy carbon electrode

An electrochemical sensor was developed for guanine and adenine detection using multiwall carbon nanotubes with the hybrid NiAl-layered double hydroxide/graphene oxide (NiAl-LDH/GO) on a glassy carbon electrode.

Voltammetric determination of TBHQ at a glassy carbon electrode surface activated by in situ chemical oxidation

Bare GCE surface is directly activated by in situ chemical method, and the modified GCE exhibits a rougher surface and a negative-charge characteristic.

A simple, but highly sensitive, graphene-based voltammetric sensor for salvianic acid A sodium

A simple, but highly sensitive, electrochemical sensor for the determination of salvianic acid A sodium (SAS) based on reduced graphene oxide (rGO) is reported. The sensor (rGO/GCE(ox)) was prepared by coating an rGO film on the surface of a pre-anodized glassy carbon electrode (GCE(ox)) through a dipping-drying method. The characteristic of the modified electrode was examined by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Compared with bare GCE, GCE(ox) and rGO modified GCE, this sensor exhibited a superior ability for detecting SAS. Under the selected conditions, the reduction current had a good linear relationship with the SAS concentration in the range of 8.0 × 10(-8) - 2.0 × 10(-5) mol L(-1), with a low detection limit of 2.0 × 10(-8) mol L(-1). Furthermore, the method was also successfully applied to detect SAS in medicinal tablets.

SiC nanoparticles-modified glassy carbon electrodes for simultaneous determination of purine and pyrimidine DNA bases

For the first time a novel and simple electrochemical method was used for simultaneous detection of DNA bases (guanine, adenine, thymine and cytosine) without any pretreatment or separation process. Glassy carbon electrode modified with silicon carbide nanoparticles (SiCNP/GC), have been used for electrocatalytic oxidation of purine (guanine and adenine) and pyrimidine bases (thymine and cytosine) nucleotides. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) techniques were used to examine the structure of the SiCNP/GC modified electrode. The modified electrode shows excellent electrocatalytic activity toward guanine, adenine, thymine and cytosine. Differential pulse voltammetry (DPV) was proposed for simultaneous determination of four DNA bases. The effects of different parameters such as the thickness of SiC layer, pulse amplitude, scan rate, supporting electrolyte composition and pH were optimized to obtain the best peak potential separation and higher sensitivity. Detection limit, sensitivity and linear concentration range of the modified electrode toward proposed analytes were calculated for, guanine, adenine, thymine and cytosine, respectively. As shown this sensor can be used for nanomolar or micromolar detection of different DNA bases simultaneously or individually. This sensor also exhibits good stability, reproducibility and long lifetime.