In situ synthesis of silver nanoparticles on dialdehyde cellulose as reliable SERS substrate

Dialdehyde cellulose (DAC) has considerable potential as an effective metal nanoparticle support material for the preparation of highly sensitive SERS substrates. In this study, a SERS substrate based on the Tollens reaction of DAC was successfully prepared. DAC was obtained by selective oxidation of cellulose nanocrystals (CNCs) with sodium periodate (NaIO4). And the aldehyde group of DAC underwent REDOX reaction with Tollens reagent to produce silver nanoparticles (Ag NPs) on the DAC in situ. The SERS "hot spots" can be generated in the gaps of Ag NPs. The as-prepared DAC-Ag NP nanocomposites showed excellent SERS activity with a highly sensitive rhodamine 6 G detection limit of 10–9 M. In diuron detection, an excellent linear relationship (R2 = 0.9948) was established between the concentrations of 10–8 M to 10–4 M. Furthermore, the feasibility of the proposed method in the actual samples was also confirmed. The substrate was applied to detect orange and persimmon peel which were previously treated with diuron solution. The substrate has universal applicability and is expected to be further applied in the detection of other hazardous molecules.