A Novel Layer-by-Layer Approach for the Fabrication of Conducting Polymer/RNA Multilayer Films for Controlled Release

• Published in: Langmuir 2006-03, Vol.22 (6), p.2811-2815
• Main Authors: Recksiedler, Carmen L, Deore, Bhavana A, Freund, Michael S
• Format: Article
• Language: English
• Subjects: Aniline Compounds - chemistry; Boronic Acids - chemistry; Chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; RNA - chemistry; Spectrophotometry, Ultraviolet
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la053031m

Poly(anilineboronic acid) (PABA)/ribonucleic acid (RNA) multilayer films were prepared under neutral condition using a layer-by-layer deposition of PABA and RNA. RNA was used both as a polyelectrolyte for multilayer formation as well as dopant for PABA. Photoelastic modulated infrared reflection absorption spectroscopy measurements suggest that PABA interacts covalently with RNA through the formation of a boronate ester, a boron−nitrogen dative bond, as well as electrostatic interactions of anionic phosphates with cationic amines. The deposition procedure was monitored with UV−vis absorption spectroscopy, showing a linear dependence of absorbance with the number of PABA/RNA bilayers deposited. The multilayer films were further characterized using X-ray photoelectron spectroscopy and ellipsometry, which yielded a PABA/RNA bilayer thickness of approximately 10 nm. The PABA/RNA multilayer films are redox-active at neutral pH, consistent with the formation of a self-doped polymer. Electrochemical control of PABA under these conditions allows potential-induced controlled release of RNA from a multilayer at neutral pH, suggesting that this may serve as a novel method for controlled release of RNA under physiological conditions.