Rapid and Sensitive SERS Detection of Bisphenol A Using Self-assembled Graphitic Substrates

We have prepared and tested a new surface enhanced Raman scattering (SERS) substrate based on self-assembled graphitic sheets to detect bisphenol A (BPA) in plastic consumer goods. Transmission electron microscopy (TEM) and atomic-force microscopy (AFM) were used to characterize the structure of the graphitic sheets and showed a lattice spacing of 0.24 nm and layer height of 0.34 nm. These values were comparable to single monolayer graphene. The effective SERS detection limit of this method is 1 mu M BPA, which is lower than the European Union specific migration limit for BPA of 0.6 mg/kg (2.6 mu M). When used in salt solutions, graphitic sheets exhibited ultra-sensitivity toward BPA of 0.025 M to 2 M, which was broader than physiological ionic strength (0.14 M) and urinary NaCl (0.17 M). Our results demonstrated that this graphitic sheet based SERS detection platform can be used to determine BPA levels leached from commercial polycarbonate plastic products and for on-site rapid analysis with good results.