Bacterial Cellulose Loaded with Silver Nanoparticles as Flexible, Stable and Sensitive Sers Active Substrate for Detection of Shellfish Toxin Dtx-1

Abstract

Diarrhoeal shellfish toxins are among the most serious red tide algae toxins in the world. An Ag NPs-loaded bacterial cellulose membrane (BCM) surface-enhanced Raman scattering (SERS) sensor based on an aptamer (Apt) has been proposed in this work. It was used for ultra-sensitive detection of Dinophysistoxins (DTX-1), a diarrheal shellfish toxin. Based on the porous structure and strong absorption of BCM, Ag NPs can be fixed to BCM by multiple " sorption-in situ reduction" processes. After drying, Ag NPs were further densified on BCM to form high-density SERS "hot spots". “Apt-SH @ Ag NPs @ BCM” SERS sensor was prepared by us. Using the competition of DTX-1 and complementary base (Cob) in the process of base complementary pairing, SERS detection of DTX-1 was realized, with the minimum detection limit of 9.5×10-10 mol/L. Finally, DTX-1 was successfully detected in actual samples with recovery between 95.8% and 108.2%. The reliability of the assay was further confirmed by comparing the detection results with those obtained by LC-MS. This work has great potential for the detection of hazardous substances in the aquatic environment and the safety of seafood products.

Keywords: Dinophysistoxins, surface enhanced Raman spectroscopy, Aptamer, Complementary base, Bacterial cellulose membrane