Topochemical assembly of levodopa nanoparticles network as a high-performance biosensing platform coupling with π-π stacking and electrostatic repulsion interactions

Topochemical assembly carbon materials with unique structure rarely investigated and reported. Herein, we demonstrate the feasibility of using topochemical assembly levodopa nanoparticles with dendritic structure (LNDS) network as a new high-performance biosensing platform based on noncovalent functionalization of LNDS with a fluorescent oligonucleotide. The proposed platform is dependent on the competition of π-π stacking and electrostatic repulsion interactions between LNDS and fluorescent oligonucleotide. The obtained LNDS with 96.1% quenching efficiency is synthesized by using levodopa as the single precursor by natural oxidation or microwave irradiation. The constructed platform can be used for simple and efficient probing single-nucleotide polymorphisms (SNPs) and cDNA by fluorescence restoration with a highly sensitivity and selectivity, remarkably superior to those based on graphenes. Additionally, an aptasensor is further constructed for small molecule ATP detention in serum with a low detection limit of 4 μM. To the best of our knowledge, this is the first attempt to use LNDS to design a biosensing platform, and therefore opens possibilities for new types of nanoparticle-based molecule approaches, and sequencing technologies.