A core-satellite self-assembled SERS aptasensor containing a“biological-silent region”Raman tag for the accurate and ultrasensitive detection of histamine

Herein,a novel interference-free surface-enhanced Raman spectroscopy(SERS)strategy based on magnetic nanoparticles(MNPs)and aptamer-driven assemblies was proposed for the ultrasensitive detection of histamine.A core-satellite SERS aptasensor was constructed by combining aptamer-decorated Fe_(3)O_(4)@Au MNPs(as the recognize probe for histamine)and complementary DNA-modified silver nanoparticles carrying 4-mercaptobenzonitrile(4-MBN)(Ag@4-MBN@Ag-c-DNA)as the SERS signal probe for the indirect detection of histamine.Under an applied magnetic field in the absence of histamine,the assembly gave an intense Raman signal at“Raman biological-silent”region due to 4-MBN.In the presence of histamine,the Ag@4-MBN@Ag-c-DNA SERS-tag was released from the Fe_(3)O_(4)@Au MNPs,thus decreasing the SERS signal.Under optimal conditions,an ultra-low limit of detection of 0.65×10^(-3)ng/mL and a linear range 10^(-2)-10^5 ng/mL on the SERS aptasensor were obtained.The histamine content in four food samples were analyzed using the SERS aptasensor,with the results consistent with those determined by high performance liquid chromatography.The present work highlights the merits of indirect strategies for the ultrasensitive and highly selective SERS detection of small biological molecules in complex matrices.

SERS-tag techology in food safety and detection:sensing from the"fingerprint"region to the"biological-silent"region

Surface enhanced Raman spectroscopy(SERS)offers many advantages for the fast and sensitive detection of specific compounds,metal ions or pathogens in foods,motivating to its increasing utilization in food safety.SERS-tags,typically constructed using signal enhanced substrate,Raman reporter molecules,a biocompatible protective layer and a specific recognition element,provide a powerful tool for the analysis of food hazards.This article reviews recent progress in the development of SERS-tags for food safety assessment covering SERS-tags with characteristic peaks in the“fingerprint”region(800-1800 cm-1)and the“biological-silent”region(1800-2800 cm-1).Following a brief description of SERS substrates,the design,synthesis and applications of SERS-tag are explored in detail.The application of SERS-tags technology for the detection of microorganisms,pesticides and antibiotics are then investigated.Finally,the prospects of using SERS-tag in real-world food safety analysis are critically discussed.