Incorporation of a Basil-Seed-Based Surface Enhanced Raman Scattering Sensor with a Pipet for Detection of Melamine

A basil-seed-based surface enhanced Raman scattering (SERS) sensor has been incorporated with a transfer pipet via a plastic chamber to create an integrated portable device, in which the transfer pipet is used for flow injection. A small amount of liquid sample is loaded to the dry basil-seed-based SERS sensor using the transfer pipet. The dry basil-seed can store the liquid sample like a sponge so that the plasmonic silver nanoparticles deposited on the basil-seed keep an intimate contact with the liquid sample containing the analyte, which enhances the sensitivity of the device. The excessive liquid sample is then ejected out of the plastic box by the transfer pipet, leaving the basil-seed-based SERS substrate exposed to air. This reduces the interference of the opaque liquid sample on the SERS signal, and avoids the tedious procedure for extraction of melamine from the milk. As a result, the pipet-basil-seed-based SERS device can be used to detect melamine in milk rapidly. This work has demonstrated a facile approach to construct a low-cost, safe, disposable, user-friendly, and field-deployable portable SERS device.