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

Plasmonic Cavity for Self-Powered Chemical Detection and Performance Boosted Surface-Enhanced Raman Scattering Detection

With the popularization of the Internet of Things, the application of chemical sensors has become more and more extensive. However, it is difficult for a single functional sensor to meet multiple needs at the same time. For the next generation of chemical sensors, in addition to rapid qualitative and quantitative detection, it is also necessary to solve the problem of a distributed sensor power supply. Triboelectric nanogenerator (TENG) and surface-enhanced Raman scattering (SERS) are two emerging technologies that can be used for chemical testing. The combination of TENG and SERS technology is proposed to be an attractive research strategy to implement qualitative and quantitative analysis, as well as self-powered detection in one device. Herein, the Ag nanoparticle (NP)@polydimethylsiloxane (PDMS) plasmonic cavity is demonstrated, which can be exploited not only as a SERS substrate for qualitative analysis of the target molecules but also as a TENG based self-powered chemical sensor for rapid quantitative analysis. More importantly, the as-designed plasmonic cavity enables prolonged triboelectric field generated by the phenomena of triboelectricity, which in turn enhances the “hot spot” intensities from Ag NPs in the cavity and boosts the SERS signals. In this way, the device can have good feasibility and versatility for chemical detection. Specifically, the measurement of the concentration of many analytes can be successfully realized, including ions and small molecules. The results verify that the proposed sensor system has the potential for self-powered chemical sensors for environmental monitoring and analytical chemistry