Quantitative and recyclable SERS detection induced by tunable Raman internal standard from embedded silicon nanoparticles

Abstract

Internal standard-mediated quantitative surface enhanced Raman scattering (SERS) technique has been restricted due to the reduction and collapse of intrinsic Raman signal after further modification. Alternatively, the concept of tunable internal standard was proposed and investigated here for its attractive prospect in practical application. Specifically, a recyclable PMMA@MoS2@Ag composite SERS substrate was firstly developed to enable not only the sensitive in-situ detection of pernicious molecules, but also their efficient green diminishing. Furthermore, a tailorable Raman internal standard at 520 cm−1 was developed to promote the quantification degree of the above detection by simply tuning the number of silicon nanoparticles (Si NPs) in the NaCMC polymer matrix. The obtained flexible NaCMC-Si/PMMA@MoS2@Ag hybrid substrate with enhancement factors from 1.86 × 106 to 2.88 × 109, reliable self-cleaning ability, and robust quantification effect was finally conducted in the in-situ monitoring and diminishing of mixed thiabendazole (TBZ) and vanillin (VA) on tobacco, achieving an ultra-low limit of detections as about 10−7 M and recovery rates higher than 87%. In summary, the proposed sophisticated substrate with both green degradation capability and tunable internal standard is expected to broaden the application of SERS technique in practical biochemical monitoring.