Development of a Novel Electrochemical Sensor Based on Functionalized Carbon Black for the Detection of Guanine Released from DNA Hydrolysis

Abstract

In this work, we reported a new strategy based on DNA strands hydrolysis in combination with the employment of functionalized carbon black modified screen-printed electrode (f-CB/SPE) for guanine detection. Using glass microbeads as a solid substrate of ssDNA probe fixation, and under appropriate conditions of temperature, time, and hydrochloric acid concentra-tion, DNA hydrolysis has been successfully used to release the guanine, allowing its oxidation at f-CB/SPE using differential pulse voltammetry. The selectivity was successfully tested with a non-complementary sequence, and a detection limit of 0.7 nM of the target DNA has been reached.

Electrochemical DNA Biosensor Based on Immobilization of a Non-Modified ssDNA Using Phosphoramidate-Bonding Strategy and Pencil Graphite Electrode Modified with AuNPs/CB and Self-Assembled Cysteamine Monolayer

“…Different approaches have been explored for the detection of hybridization between the immobilized ssDNA capture probe and the complementary target sequence. These approaches include direct detection methods based on guanine bases oxidation [ 37 ], as well as indirect methods based on nanoparticles [ 38 ], enzyme-labels [ 39 ], and redox-active indicators [ 40 ]. The incorporation of redox-active indicators to the DNA surface is the most popular way to monitor hybridization between the immobilized ssDNA capture probe and the complementary target sequence [ 41 ].…”