Fig. 5

Representation of the process from phage display to manufacturing of the SERS substrate. A Insertion of the cysteine-rich peptide into the major PV111 protein domain of the M13KE phage using two restriction enzymes (BtgZI and HinP1I). B The colony PCR analysis on a 1% agarose gel confirms the effective integration of the cysteine-rich peptide into the pVIII region of the M13KE plasmid. C Utilization of cysteine-rich peptide phage display for the production of SERS substrates. The phage was decorated with an immuno-colloid made of gold-coated magnetic nano-stars (Au-MNS) after treatment with tris (2-carboxyethyl) phosphine hydrochloride solution (TCEP) to activate the thiol groups. The phage was polymerized with silica precursor to give amorphous biomaterial gel and then calcinated to form the mesoporous template. After incubation of the template with a serum sample spiked with sepsis biomarkers, the complexes were separated using a magnet and subjected to Surface-enhanced Raman scattering (SERS) measurement (adopted from [20])