A SERS-active enzymatic product used for the quantification of disease-related molecules

In this paper, a method for enhancing the analysis of biologic materials was designed. This method incorporated the surface-enhanced Raman scattering (SERS) technique and an enzyme catalysis-based bioassay to develop a more efficient analysis procedure. Using this combination, the quick and simple detection of disease-related molecules (the human cardiac isoform of troponin T, cTnT) in human serum was achieved. This method utilizes enzyme catalysis to develop a H2O2-horseradish peroxidase (HRP)-3,3,5,5-tetramethylbenzidine (TMB) chromogenic system, and the final enzymatic product TMB2+ revealed perfect SERS activities. By analyzing a concentration-dependent SERS spectrum, the quantitative analysis was accomplished. Our findings reveal that the proposed method has a wider linear range and a more sensitive detection limit compared with traditional chromogenic tests. In summary, two existing methods have been combined to create a new model, which has the potential to be used for the bioanalysis and early diagnosis of diseases. Copyright (c) 2013 John Wiley & Sons, Ltd.