Electrochemical detection of anti-benzo[a]pyrene diol epoxide DNA damage on TP53 codon 273 oligomers

Area of Science:

• Environmental Science
• Analytical Chemistry
• Molecular Biology

Background:

• Polycyclic aromatic hydrocarbons, such as benzo[a]pyrene, are environmental mutagens.
• Benzo[a]pyrene diol epoxide (BPDE) is a known DNA-damaging agent.
• Detecting specific DNA damage is crucial for understanding mutagenicity and carcinogenicity.

Purpose of the Study:

• To develop and validate an electrochemical sensor for detecting DNA damage.
• To investigate BPDE-induced DNA damage at a TP53 gene hotspot.
• To establish a sensor for sequence-related xenobiotic DNA damage.

Main Methods:

• Electrochemical detection using gold electrodes immobilized with double-stranded DNA oligomers.
• Voltammetric measurements in the presence of a redox-active viologen compound (C12-viologen).
• Mass spectrometry and UV thermal melting experiments for mechanistic insights.

Main Results:

• An electrochemical signal (redox wave at -0.37 V vs. Ag/AgCl) emerged upon BPDE exposure to DNA-modified electrodes.
• The signal intensity correlated with BPDE concentration and exposure time.
• The sensor specifically detected BPDE damage at the wild-type TP53 sequence, with a detection limit of approximately 170 nM.

Conclusions:

• An electrochemical hybridization sensor can effectively detect xenobiotic DNA damage at specific sequences.
• This method offers a sensitive approach for identifying genotoxic agents.
• The sensor provides a valuable tool for environmental monitoring and toxicological studies.