León, John Jairo Castillo1; Rindzevicius, Tomas6; Wu, Kaiyu1; Schmidt, Michael Stenbæk6; Janik, Katarzyna Agnieszka7; Boisen, Anja6; Svendsen, Winnie Edith8; Rozlosnik, Noemi9; Castillo, Jaime1
1 Department of Micro- and Nanotechnology, Technical University of Denmark2 Nanoprobes, Department of Micro- and Nanotechnology, Technical University of Denmark3 Center for Electron Nanoscopy, Technical University of Denmark4 Nano Bio Integrated Systems, Department of Micro- and Nanotechnology, Technical University of Denmark5 Polymer Microsystems for Medical Diagnostics, Department of Micro- and Nanotechnology, Technical University of Denmark6 Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics, Center, Technical University of Denmark7 DTU Danchip, Technical University of Denmark8 Copenhagen Center for Health Technology, Center, Technical University of Denmark9 Risø National Laboratory for Sustainable Energy, Technical University of Denmark
Herein, we describe the synthesis and characterization of a covalent nanoscale assembly formed between diphenylalanine micro/nanotubes (PNT) and folic acid (FA). The conjugate was obtained via chemical functionalization through coupling of amine groups of PNTs and carboxylic groups of FA. The surface analysis of PNT-FA indicated the presence of FA aggregates on the surface of PNTs. The covalent interaction between FA and self-assembled PNTs was further investigated using fluorescence microscopy, Raman and surface-enhanced Raman scattering (SERS) spectroscopies. The SERS experiments were performed on a large area silver-capped (diameter of 62 nm) silicon nanopillars with an approximate height of 400 nm and a width of 200 nm. The results showed that the PNT-FA synthesis procedure preserves the molecular structure of FA. The PNT-FA conjugate presented in this study is a promising candidate for applications in the detection and diagnosis of cancer or tropical diseases such as leishmaniasis and as a carrier nanosystem delivering drugs to malignant tumors that overexpress folate receptors.
Journal of Nanoparticle Research, 2014, Vol 16, Issue 7