Adsorption and Detection of DNA Dendrimers at Carbon Electrodes

Abstract

Dendritic nucleic acids are highly branched and ordered molecular structures, possessing numerous single-stranded oligonucleotide arms, which hold great promise for enhancing the sensitivity of DNA biosensors. This article evaluates the interfacial behavior and redox activity of nucleic acid dendrimers at carbon paste electrodes, in comparison to DNA. Factors influencing the adsorption behavior, including the adsorption potential and time, solution conditions, or dendrimer concentration, are explored. The strong adsorption at the anodically pretreated carbon surface is exploited for an effective preconcentration step prior to the chronopotentiometric measurement of the surface species. Coupled with the numerous guanine oxidation sites, such stripping protocol offers remarkably low detection limits (e.g., 3 pM or 2.4 femtomole of the 4-layer dendrimer following a 15 min accumulation). The new observations bear important implications upon future biosensing applications of nucleic dendrimers.

Current strategies for electrochemical detection of DNA with solid electrodes

“…PNA and DNA dendrimers are used to enhance the sensitivity of detection by increasing the surface coverage. Few applications with electrochemical detection have yet been reported, however [6]. Electrochemical hairpins are DNA probes with a self-complementary sequence at both ends of the sequence, complementary to the target, that are tagged with a redox-active label at one end.…”

Electrochemical behavior of a new s-triazine-based dendrimer

“…The peripheral redox active units undergo multiple electron transfer and the redox properties can be modulated by the size and nature of the dendritic branches [18,19].…”

Immobilization and electro-oxidation of calf thymus deoxyribonucleic acid at alkylamine modified carbon nanotube electrode and its interaction with promethazine hydrochloride

“…Electrochemical transducers using DNA layers as recognition element are very attractive for these applications, owing to high sensitivity, inherent simplicity, low cost and power requirements. Voltammetry and potentiometric stripping methods have been used to investigate the electrochemical behavior of the immobilized DNA and their interaction with chemical compounds [2][3][4][5][6][7][8][9]. Undoubtedly, immobilization of DNA on electrode surfaces is a crucial step for DNA electrochemistry.…”