Flexible, transparent and robust SERS tapes through a two-step block copolymer self-assembly process

Surface enhanced Raman spectroscopy (SERS) is an analytical technique that offers the capability of remote sensing, single molecule detection, and detection of trace contaminants (in parts per million) with high sensitivity and accuracy. Here, we demonstrate a simple and economical method for fabricating large area SERS-active tapes that are flexible, transparent and robust using a two-step process. The first is the fabrication of the gold nanoclusters on a flat chip using block copolymer self-assembly followed by directed electrostatic self-organization of gold nanoparticles (AuNPs). The second step involves the transfer of the resulting metal nanoclusters onto a thermal tape by a simple 'stick and peel' technique. Such substrates facilitate the detection and quantification of contaminants on irregular surfaces such as fruit skin, fabrics and other non-planar surfaces without the need to extract the analyte. Furthermore, the SERS measurements are highly quantitative, reproducible and the two-step fabrication process is unprecedented and has potential towards realizing large scale manufacturing of low-cost, flexible SERS-tape for on-field applications.