Electrochemical DNA Biosensor Based on Magnetite/Multiwalled Carbon Nanotubes/Chitosan Nanocomposite for Bacillus Cereus Detection of Potential Marker for Gold Prospecting

Abstract

A label‐free DNA biosensor based on magnetite/multiwalled carbon nanotubes/chitosan (Fe3O4/MWCNTs‐COOH/CS) nanomaterial for detection of Bacillus cereus DNA sequences was fabricated. Negatively charged DNA was electrostatically adsorbed onto materials by protonation of positively charged chitosan under acidic conditions. The electrode surface and hybridization process were carried out by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Under optimal conditions, the biosensor showed a good linear relationship between peak currents difference (ΔI) and logarithm of the target DNA concentration (Log C) ranging from 2.0×10−13 to 2.0×10−6 M with a detection limit of 2.0×10−15 M (signal/noise ratio of 3). The biosensor also revealed an excellent selectivity to three‐base, completely mismatched and completely matched DNA. This is a simple, fast and friendly method with a low detection limit for the detection of Bacillus cereus specific DNA compared with previously reported electrochemical DNA biosensor. Furthermore, the DNA biosensor may lead to the development of a technology for gold prospecting in the wild.

Advanced Methods for Detection of Bacillus cereus and Its Pathogenic Factors

“…Indeed, trained professionals are required to perform this type of assays, which are still laborious (PCR test takes from 2 h to 24 h) and costly. Sometimes amplification errors occur, or false-negative results may be obtained when using complex matrices such as blood or food samples [46][47][48]. Another limitation of PCR is the use of laborious, time-consuming and low-resolution gel electrophoresis methods to visualize PCR products.…”

“…In the last few years, biosensors have emerged as ideal methods for the detection of foodborne pathogens [6,52,53,[55][56][57][58][59]. The success of these miniaturized devices is mainly due to their rapidity to provide results, simplicity, and possibility of point-of-care diagnosis together with the low cost and high reliability of analysis [46,60]. In addition, only a small amount of sample is required to perform the analysis [61,62].…”

An Ultrasensitive Electrochemical DNA Biosensor Based on Carboxylated Multi-walled Carbon Nanotube/Molybdenum Disulfide Composites for KRAS Gene Detection

“…When target DNA (1.0 × 10 -7 M) was added for successful hybridization, the peak current further declined (curve d), because of blocking of the electron transfer on the surface, which was caused by the double-stranded structure of the capture-target DNA. [52][53][54]…”

Enzyme-functionalised, core/shell magnetic nanoparticles for selective pH-triggered sucrose capture

“…5,6 The use of magnetic separation started with the mining industry and have expanded to coal desulphurisation, steel production, biotechnology, wastewater treatment, 7 bioremediation, 8 pharmaceutical 9 and biomedical applications. [10][11][12] Magnetic separations are very promising for the food industry and downstream biotechnology processes, which can be explained by its main advantages: one-step capture and purication, due to its high affinity and selectivity; the possibility of high throughput and semi-continuous processes with low energy consumption. Therefore, magnetic separation can aid in increasing yields and productivity, while reducing costs of industrial processes.…”