Due to the enhanced surface area, three-dimensional (3D) fibrous meshes produced by the electrospinning technique are preferred over two-dimensional (2D) planar substrates in many application areas, one of which is sensing. In our work, a highly dense and homogeneous gold nanorod (AuNR) assembly was produced on electrospun polycaprolactone (PCL) fibers using electrostatic attraction as the driving force. Specifically, negative and positive charges were established on the AuNRs and the PCL fibers via polyelectrolyte decoration, respectively. Immobilization of the AuNRs was realized under electrostatic attraction. The AuNR/PCL nanocomposite fibers obtained were utilized as a substrate in the surface enhanced Raman scattering (SERS) measurements and showed a 104-105 enhancement factor for 4-mercaptopyridine with excellent reproducibility. Compared to the 2D AuNR/PCL film fabricated using the same protocol, the SERS signal recorded on the 3D fibrous mesh has been effectively improved by 6-fold. By attaching 1,3,5-triazine-2,4,6-trithiol (TMT) to the AuNRs as the bridging molecule, a trace amount of Cu2+ in the aqueous solution can be detected. A good linear relationship was established between the concentration of Cu2+ and the relative intensity ratio of TMT bands at 1234 cm-1/973 cm-1. Hence this can now be utilized as the calibration curve to quantitatively determine the concentration of Cu2+. Using a similar strategy, quantitative detection of Hg2+ can be achieved by using 1,3,4-thiadiazole-2,5-dithiol as the bridging molecule.

Fabrication of gold nanorod/polymer nanocomposite fibers and their application in heavy metal ion sensing via SERS

247th National Meeting (2014)

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