CNTs-anchored egg shell membrane decorated with Ag-NPs as cheap but effective SERS substrates

We report a simple approach for the fabrication of cheap but effective surface-enhanced Raman scattering (SERS) active substrates consisting of natural egg shell membrane (ESM) grafted with Ag-nanoparticles (Ag-NPs) decorated carbon nanotubes (CNTs) (denoted as Ag-NPs@CNTs@ESM), via ultrasonic adsorption of CNTs on the ESM and the subsequent Ag-sputtering. As high density Ag-NPs were sputtered onto each CNT anchored on the ESM nanofiber, homogeneous nanoscaled gaps between the neighboring Ag-NPs were achieved, leading to high SERS activity with excellent SERS signal homogeneity over the whole membrane. Using the Ag-NPs@CNTs@ESM membranes as SERS-substrates, methyl parathion (one of the most hazardous insecticides), PCB-3 (one congener of polychlorinated biphenyls belonging to persistent organic pollutants) and bovine serum albumin (BSA, biomolecules) with a concentration down to 10−11 M, 10−6 M and 0.1 ppb were detected respectively, showing promising potentials in rapid trace detection of environmental pollutants and biochemicals.