Assembling of anisotropic plasmonic sheet-core-satellites for simultaneous ultrasensitive detection of MC-LR toxin†
An anisotropic plasmonic sheet-core-satellite (PSCS) superstructure can be controlled via competitive binding between aptamer/MC-LR conjugation and aptamer-ssDNA hybridization. SERS nanotags can be incorporated into anisotropic plasmonic sheet-cores, e.g., pGO/nanorods, or pGO/hollow AgCl : Au nanoplates so as to fabricate an aptasensor for “ON–OFF” detection of MC-LR toxin. Preparing a PSCS superstructure and detection of toxin can be simultaneously completed so as to simplify the detection procedure of MC-LR toxin. Detection sensitivity of MC-LR toxin can be optimized by controlling aspect ratios or hollow interiors of plasmonic core nanoparticles. Herein, a limit of detection (0.635 pM) with a wide linear range from 1 pM to 10 nM can be obtained via optimized PSCS of pGO/nanorod/dotnanotags. When the aptasensor was tested in real samples, the PSCS shows excellent recoveries from 96.6% to 104.5% with relative standard deviation (RSD) lower than 2.89% in spiked reservoir samples. It can be predicted that a one-step facile nanofabrication/aptasensing approach would be extensively applied for rapid detection of some other environmental contaminants.