Electric Field Promoted Click Surface-Enhanced Raman Spectroscopy for Rapid and Specific Detection of DNA 2-Deoxyribose 5'-Aldehyde Oxidation Products in Plasma

Rapid identification of DNA oxidative damage sites is of great significance for disease diagnosis. In this work, electric field-regulated click reaction surface-enhanced Raman spectroscopy (e-Click-SERS) was developed aiming at the rapid and specific analysis of furfural, the biomarker of oxidative damage to the 5-carbon site of DNA deoxyribose. In e-Click-SERS, cysteamine-modified porous Ag filaments (cys@p-Ag) were prepared and used as electrodes, amine-aldehyde click reaction sites, and SERS substrates. Cysteamine was controlled as an end-on conformation by setting the voltage of cys@p-Ag at -0.1 V, which ensures its activity in participating in the amine-aldehyde click reaction during the detection of furfural. Benefiting from this, the proposed e-Click-SERS method was found to be sensitive, rapid-responding, and interference-resistant in analyzing furfural from plasma. The method detection limits of furfural were 5 ng mL(-1) in plasma, and the whole extraction and detection procedure was completed within 30 min with satisfactory recovery. Interference from 13 kinds of common plasma metabolites was investigated and found to not interfere with the analysis, according to the exclusive adaptation of the amine-aldehyde click reaction. Notably, the e-Click-SERS technique allows in situ analysis of biological samples, which offers great potential to be a point-of-care testing tool for detecting DNA oxidative damage.

Automated summary

The electric field-regulated click reaction surface-enhanced Raman spectroscopy (e-Click-SERS) is a rapid and specific method for identifying DNA oxidative damage sites. The e-Click-SERS method utilizes cysteamine-modified porous Ag filaments as electrodes, amine-aldehyde click reaction sites, and SERS substrates, and exhibits sensitivity, rapid response, and interference resistance in analyzing furfural as a biomarker of oxidative damage. The interference from 13 common plasma metabolites is eliminated due to the exclusive adaptation of the amine-aldehyde click reaction. The technique allows for in situ analysis of biological samples and holds great potential for point-of-care testing in detecting DNA oxidative damage.