ATP mediated rolling circle amplification and opening DNA-gate for drug delivery to cell.

Here, we have developed a facile fluorometric system for the detection of adenosine triphosphate (ATP) by a rolling circle amplification (RCA) based on proximity ligation mediated amplification, and simultaneously achieved the release of the anticancer drug doxorubicin (DOX) through the mesoporous silicon system. Once the ATP molecule is present, the linker DNA will be released from the graphene oxide (GO) surface and hybridized to the template DNA of the GO surface joining with ligation enzyme. RCA reaction is followed by the addition of the phi29 DNA polymerase. The product of RCA reaction contains a base fragment complementary to the signal DNA, allowing the fluorescent oligonucleotide probe to be released from the GO surface and fluorescence is recovered. The strong fluorescence signal realized the sensitive detection of ATP. Gate DNA were modified to the surface of the mesoporous silica (MSN) by electrostatic attraction to encapsulate DOX. After the above-mentioned RCA process, its result that long DNA chain containing a base fragment complementary to gate DNA, would be hybridized to the gate DNA strand on the surface of MSN, which opened the MSN hole and released the drug DOX into cell for HeLa cell therapy. And the specificity to folate receptor overexpressed on cell surface was satisfactory which would be beneficial for cancer therapy.