Sensitive electrochemical detection of DNA damage based on in situ double strand growth via hybridization chain reaction.

Detection of DNA damage caused by ∙OH or radiation has led to rapidly growing interest in the fields of drug development, biochemistry, clinic diagnostics, and environmental evaluation. Electrochemical methods have been applied for DNA damage detection because of their fast and sensitive response. However, most of the electrochemical methods for DNA damage detection commonly require immobilization of the strands on the electrode surface. In the present work, sensitive electrochemical monitoring of DNA damage was realized successfully on the basis of in situ DNA chain growth by use of a hybridization chain reaction (HCR) technique. By use of [Ru(NH3)6]3+ as the signal probe and the Fenton reaction as the ∙OH generator, ultrasensitive detection of DNA damage induced by ∙OH was realized successfully through differential pulse voltammetry with a linear relationship of ∙OH concentration from 15 to 750 pM and a detection limit of 12 pM. Furthermore, environmental DNA-damaging UV light was tested as the lesion source to demonstrate the practicability and reliability of the proposed HCR-based amplified signal method for DNA damage detection. By integrating the HCR technique with an electrochemical method, we provide a promising alternative approach to extend the applications of electrochemical methods in bioanalytical detection of DNA damage. Graphical abstract Sensitive electrochemical monitoring of DNA damage has been realized successfully on the basis of in situ DNA chain growth by use of hybridization chain reaction (HCR). Detection of DNA damage caused by ∙OH was realized successfully through differential pulse voltammetry with a linear relationship of ∙OH concentration from 15 to 750 pM and a detection limit of 12 pM.