Gold sputtered Blu-Ray disks as novel and cost effective sensors for surface enhanced Raman spectroscopy

Abstract

Surface Enhanced Raman spectroscopy (SERS) offers sensitive and non-invasive detection of a variety of compounds as well as unparalleled information for establishing the molecular identity of both inorganic and organic compounds, not only in biological fluids but in all other aqueous and non-aqueous media. The localized hotspots produced through SERS at the solution/nanostructure interface of clustered gold or silver nano-particles enables detection levels of parts per trillion. Recent developments in advanced fabrication methods have enabled the manufacture of SERS substrates with repeatable surface nanostructures which provide reproducible quantitative analysis, historically a weakness of the SERS technique. In this paper we describe the novel use of gold sputtered Blu-Ray surfaces as SERS substrates. Blu-Ray disks provide ideal surfaces of SERS substrates with their repeatable and regular nano-gratings. We show that the unique surface features and composition of the recording surface enables the formation of gold nano-islands with nanogaps, simply through gold sputtering, and relate this to a 600 fold signal increase of the melamine Raman signal in aqueous solutions and detection to 68 ppb. Melamine is a triazine compound and appears not only as environmental contaminant in environmental groundwater but also as an adulterant in foods due to its high nitrogen content. We have shown significant SERS signal enhancements for spectra of melamine using gold-sputtered Blu-Ray disk surfaces, with reproducibility of 12%. Blu-Ray disks have a unique combination of design, surface features and composition of the recording surface which makes them ideal for preparation of SERS substrates by gold sputter-coating.

Blu-Ray Discs as Universal Biochip Substrates: Lithography-Free Surface Activation and Assay Patterning

“…Nieuwoudt gratings of a BD to create inexpensive substrates for surfaceenhanced Raman spectroscopy. 25 Smith et al has "repurposed" Blu-ray movie discs as quasi-random nanoimprinting templates for photon "management" in the patterned metal electrodes for solar cells. 26 Recently, Maquieira and co-workers have demonstrated their enzyme inhibition microassays on BDs for drug discovery based on a physical immobilization (passive adsorption) approach.…”

“…However, only limited studies have been reported in exploring BDs for materials and analytical chemistry applications. Nieuwoudt et al sputtered gold films on the nanostructured gratings of a BD to create inexpensive substrates for surface-enhanced Raman spectroscopy . Smith et al has “repurposed” Blu-ray movie discs as quasi-random nanoimprinting templates for photon “management” in the patterned metal electrodes for solar cells .…”

Blu-ray Technology-Based Quantitative Assays for Cardiac Markers: From Disc Activation to Multiplex Detection

“…Arnadis-Chover et al has modified a Blu-ray drive by incorporating an external amplification/detection board for reading disc-based high-density DNA hybridization arrays and competitive immunoassays for microcystins . Nieuwoudt et al sputtered gold films on the nanostructured gratings of a BD to create inexpensive substrates for surface-enhanced Raman spectroscopy . Donolato et al converted a Blu-ray optical pick-up unit into an optomagnetic reading device to monitor the Brownian relaxation dynamics of modified magnetic nanoparticles in microfluidic devices for the quantitation of E. coli DNA .…”