In-situ SERS detection strategy based on electric charge adsorption between nanoparticles formed with an effective hetero-charged electric field for detecting polystyrene nanoparticle in aqueous solution

Abstract

The in-situ detection of nanoplastics (NP) has attracted a great deal of attention due to their poisonous properties for both human beings or marine organism. Surface Enhanced Raman Scattering (SERS) is utilized to distinguish a typical NP, polystyrene (PS). However, PS NPs in aqueous solution could barely be detected through SERS. In this research, a SERS detection strategy based on the electric charge adsorption of the designed hetero-charged PS NPs and AuNPs was brought out. Under this strategy, the intensity of the Raman signal in aqueous solution was strong enough to identify PS NPs, and the lowest detection line was 0.08 wt%. All result indicated that once the spacing distance lower than 2 nm would have a great SERS performance. Moreover, the particles relationship of this SERS detection discovered by the FETEM results was different from the traditional SERS detection strategy. The SERS performance was related to the number of the PS NPs surrounded the AuNPs, and the intensity of the superposition electric field would have a progressive linear relationship with the number of the charged surrounded PS NPs. All these principle and phenomena would suit for further research of the MPs/NPs in marine pollution or detection biomarker in vivo directly.