Ferrocene conjugated DNA for biosensing and antisense applications

In order to enhance the sensing capabilities of DNA, an array of tags and modified nucleic acids have been synthesised. This thesis studies both the sensing capabilities and the stability of electrochemical DNA reporters based on the redox active molecule ferrocene. The topics covered are as follows: 1. Two synthetic ferrocene nucleic acid (FcNA) DNA mimics and a redox-active tag based on two covalently connected ferrocene molecules were incorporated into the backbone of a DNA strand in a central position and the 5’ end of a DNA strand, respectively. These probes were then used to form mixed monolayers and their stability was assessed. DNA target detection was possible with square wave voltammetry due to the unusual reliance of this technique on the ‘critical frequency’ of the redox active molecule. 2. DNA probes containing thymine-modified FcNA reporter groups were investigated further due the ability of mercuric ions (Hg2+) to bind covalently to two opposite thymine groups. Detection of these ions was possible through both cyclic voltammetry and square wave voltammetry. 3. The FcNA-conjugated DNA probes are assessed for their potential as therapeutic antisense agents by exposing the single stranded and duplexed probes to a DNase and two types of exonuclease enzyme