Blu-ray DVD as SERS substrate for reliable detection and quantification of urea

Abstract

Periodically patterened metal nanostructures or chemically stable metal nano particles incoporated in naturally availbale structure provides an optimal signal-enhancement for sensitive detection of chemicals through Surface Enhanced Raman scattering (SERS) process. In this work we demonstrate the use of AuNP coated Blu-Ray DVD (BR-DVD) as SERS substrate which has proven itself to be a cost-effective and reliable technique. Owing to the high refractive index (1.58) of the polycarbonate material, the nano-channels in BR-DVD effectively guides the incident electromagnetic field in the channels thereby increasing the effective storage time of localized plasmon field. This leads to the enhancement in the Raman signal intensity of the analytes. The enhancement factor of the proposed SERS substrate is estimated to be of the order of 107. With the developed SERS substrate, malachite green (MG) concentration as low as 0.2nM has been detected reliably. The developed substrate yields a good reproducibility characteristic with relative standars deviation value (RSD) of 14.33%. Urea–the diamide of carbonic acid is a dominant nitrogen containing compound found in human urine is crucial for different clinical diagnosis purposes.. With the designed SERS substrate urea concentration as low as 0.06µg/dL can be detected reliably and accurately.