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

Abstract

In this paper, a method for enhancing the analysis of biologic materials was designed. This method incorporated the surfaceenhanced 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 H 2 O 2 -horseradish peroxidase (HRP)-3,3′,5,5′-tetramethylbenzidine (TMB) chromogenic system, and the final enzymatic product TMB 2+ 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.

Surface enhanced Raman scattering as a probe of the cholesterol oxidase enzyme

“…As well as the lines observed on the curve (c) (Figs. 3 and 4) which are typical for proteins, appear due to SERS (in previous publications, [32][33][34][35] dedicated to ChOX the oscillation spectra are not presented). It is well known 15,16 that when the size of nanoparticles is reduced, the lines amplitude is increased.…”

Patterned Superhydrophobic SERS Substrates for Sample Pre-Concentration and Demonstration of Its Utility through Monitoring of Inhibitory Effects of Paraoxon and Carbaryl on AChE

“…In this work, we described results from AChE experiments, but it is obvious that many other enzymes can be monitored in a similar fashion [51]. The key is finding proper enzyme substrates whose SERS activity can be switched on or "unmasked" upon the enzyme activity, and the end product exhibits a high affinity toward a noble metal surface [52,53].…”

Catalytic gold nanostars for SERS-based detection of mercury ions (Hg2+) with inverse sensitivity

“…Three main Raman bands corresponding to oxTMB could be observed at 1608 cm -1 , 1336 cm -1 and 1190 cm -1 (Fig. 1c), which could be attributed to ring stretching and C-H bending, inter-ring C-C stretching and CH 3 bending, respectively 22 and provided evidence that a blue CTC had occurred, due to the oxidation of TMB 20 . In addition, another Raman band at 1401 cm -1 was observed in the fingerprint spectra of oxTMB from the stretching vibration of N=N, as a result of azo compound or unoxidized TMB, which was also enhanced by the presence of AuNSt 21 .…”

“…their sharp tips, could produce phenomenal Raman enhancement [15][16][17] and therefore, they have also been exploited for the design of SERS-sensors for Hg 2+ detection 18,19 . Unlike previously reported research, the presented mechanism involves the catalytic activity of AuNSt for the oxidation of 3,3',5,5'-tetramethybenzidine (TMB) in the presence of H 2 O 2 to produce oxidised TMB (oxTMB), a highly Raman active product [20][21][22] . We observed that in the presence of Hg 2+ ions, the Au-Hg amalgamation could even enhance the catalysed oxidation reaction as evident by the strong blue coloured oxTMB product.…”