Self‐Assembled Multilayers of Polyethylenimine and DNA: Spectrophotometric and Electrochemical Characterization and Application for the Determination of Acridine Orange Interaction

Abstract

This work deals with the study of the interaction between acridine orange (AO) and calf-thymus double stranded DNA (dsDNA) present in supramolecular architectures built on gold electrodes modified with mercapto-1-propanesulfonic acid (MPS) by self-assembling of polyethylenimine and dsDNA. The optimal conditions for building the supramolecular architecture were obtained from UV-vis spectrophotometric experiments. The electrochemical studies were performed by adsorptive transfer square wave voltammetry from the evaluation of the oxidation signal of AO accumulated within the multistructure. The effect of the number of PEI-dsDNA bilayers (Au/MPS/(PEI-dsDNA) n ) on the accumulation and electrooxidation of AO is also discussed.

A closer physico-chemical look to the Layer-by-Layer electrostatic self-assembly of polyelectrolyte multilayers

“…Table 1 reports some examples of multilayers growing linearly and non-linearly. [89,107,111,118,184,191] PDADMAC with a high effective charge density (low ionic strength conditions) (PAA -PLL) n [117] Assembly using polyelectrolytes with low molecular weight (PAH -PAA) n [119,186] Assembly dependent on the pH and charge density of the polymers (PAH-PSS) n [184,185,191] Almost independent on the conditions used for the assembly (PM2VP -PSS) n [186] (PDMA -PMAA) n [192] (PEI -DNA) n [193] (PEI -BSA) n [194] (PEI -PAA) n [195] (CHI -CMC) n [196] (CHI -ALG) n [197,198] (PEI -ALG) n [197] Non-Linear Growth PEMs (CHI -PAA) n [50,51,199] (PDADMAC-PSS) n [89,107,111,118,184,191] PDADMAC with a low effective charge density (low ionic strength conditions) (PAH -PAA) n [119] Assembly dependent on the pH and charge density of the polymers (PAH-PSS) n [120] Assembly at high temperatures (T > 55 ° C) (PLL -HA) n [188,189,200,201] (PAH -HA) n [199] (CHI -HA) n [199,202] (PLL -PGA) n [203] (CHI -PGA) n…”

A reversible fluorescence nanoswitch based on bifunctional reduced graphene oxide: use for detection of Hg2+ and molecular logic gate operation

“…The spectrum of the aqueous solution of monomeric AO features an intense absorption band at 490 and 268 nm. 15 When Hg 2+ was added to the AO solution during the titration process, the intensity of the original absorption band at 490 and 268 nm did not change (Fig. S7, ESIw).…”

Nanomaterial-Assisted Signal Enhancement of Hybridization for DNA Biosensors: A Review

“…During these years, many techniques, e.g., chromatography, spectrophotometry and spectrophoto-fluorimetry, in addition to electrochemical methods, have been developed for the detection of DNA hybridization due to its significant applications in life sciences, medicine, electronics, etc. [ 34 – 37 ]. Among them, electrochemical methods are of particular interest worldwide because of their fascinating advantages, such as relatively excellent selectivity and sensitivity, low cost, and low-interference characteristics.…”