Development of a Compact Plasmonic Biosensing Platform Based on Chemically Synthesized Gold Triangular Nanoprism

The development and characterization of a biosensing platform utilizing chemically synthesized gold triangular nanoprisms is reported. These nanoprisms are specially designed to have stable deposition on a glass substrate with plasmon resonances tuned to visible-NIR wavelengths. The biosensing protocol of DNA-RNA hybridization is utilized by tagging these nanoprisms with a complementary sequence of DNA achieving specific detection of the targeted complementary miRNA. A nanoprisms-coated glass substrate having sensitivity around 300 nm/RIU has been used to detect ultralow concentrations up to 100fM of miRNA of 25 base-pair sequences. The sensing activity is further extended to nanoprisms deposited u-bent optical fiber probes that not only contribute robustness to the system but also characterization shows higher sensitivity up to 600 nm/RIU.