Enhanced Detection of Human Plasma Proteins on Nanostructured Silver Surfaces

In chemical and medical research, recent methods combine the tools of nanotechnology, chemistry and biology in a way that introduces the most modern processes to current medical practice. The main blood plasma proteins – albumin and globulin and their amino acid sequences, are carriers of important information about human health. In this paper we employed silver nanostructured surfaces prepared by electrodeposition. Consequently, electrochemical deposition is introduced as a convenient, fast and cost-effective method for the preparation of metallic nanostructures with required morphology. Silver nanostructured surfaces were applied as the templates for Surface Enhanced Raman Spectroscopy (SERS) of albumin and globulin in the role of model analytes. We also studied the effect of a working electrode polishing process on electrodeposition and identification of proteins. The aqueous solutions of albumin and globulin were applied onto these Ag nanostructured substrates separately. An analytical signal enhancement factor of 3.6×102 was achieved for a band with a Raman shift of 2104cm-1 for globulin deposited onto silver nanostructured film on unpolished stainless steel substrate. The detection limit was 400μg/mL. Plasma or serum could present a preferable material for noninvasive cancer disease diagnosis using the SERS method.