Plasmonic SERS Au Nano-Sunflowers for Sensitive and Label-Free Diagnosis of DNA Bases Damage in Stimulus-Induced Cell Apoptosis

Molecular diagnosis and accurate damage analysis of complex genomic DNAs in tumor cells are crucial to the theranostics of cancers but still a huge challenge. Herein, by designed preparation of an uniform plasmonic sunflower-like assembly gold (Au) nanostructure that capable of efficient DNA capture and providing high-density gap-plasmon "hot spots" for adequate SERS enhancement, we succeeded in sensitive and reliable label-free SERS detection of DNA damage in electrostimulus-induced apoptotic cancer cells at the DNA bases level, for the first time. The SERS results showed that the external electrostimulus (at 1.2 V, for 5 min) was almost harmless to normal healthy cells but it caused pronounced double strands break and Adenine base damage in cancer cell DNAs, which effectively destroyed the reproduction and transcription of DNAs and ultimately induce cell apoptosis. The developed sensing platform and method are promising for cell study of genetically related diseases.