Fig. 1. Self-constructed 785 nm Raman spectrum test platform

Fig. 2. SERS of PDGF-BB aqueous solution with mass fraction of 10-7 and nanosilver colloid solution

Fig. 3. SERS profiles of various low concentrations of PDGF-BB aqueous solution. (a) Mass fraction of 10-6; (b) mass fraction of 5×10-7; (c) mass fraction of 5×10-8; (d) mass fraction of 10-8

Fig. 4. SERS profiles of urine of healthy human and the mixture of urine and PDGF-BB aqueous solution with mass fraction of 10-7

Fig. 5. SERS profiles of urine samples of patients with PCI and without PCI

Fig. 6. Raman spectrum and SERS profile of urine sample of patient with PCI