A Colorimetric/Fluorescent Dual-Mode Aptasensor for Salmonella Based on the Magnetic Separation of Aptamers and a DNA-Nanotriangle Programmed Multivalent Aptamer
Author:
Ma Na12, Sun Mengni12, Shi Hanxing12, Xue Liangliang12, Zhang Min12, Yang Wenge12, Dang Yali12ORCID, Qiao Zhaohui12ORCID
Affiliation:
1. College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315800, China 2. Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, Ningbo University, Ningbo 315800, China
Abstract
Salmonella infection has emerged as a global health threat, causing death, disability, and socioeconomic disruption worldwide. The rapid and sensitive detection of Salmonella is of great significance in guaranteeing food safety. Herein, we developed a colorimetric/fluorescent dual-mode method based on a DNA-nanotriangle programmed multivalent aptamer for the sensitive detection of Salmonella. In this system, aptamers are precisely controlled and assembled on a DNA nanotriangle structure to fabricate a multivalent aptamer (NTri-Multi-Apt) with enhanced binding affinity and specificity toward Salmonella. The NTri-Multi-Apt was designed to carry many streptavidin-HRPs for colorimetric read-outs and a large load of Sybr green I in the dsDNA scaffold for the output of a fluorescent signal. Therefore, combined with the magnetic separation of aptamers and the prefabricated NTri-Multi-Apt, the dual-mode approach achieved simple and sensitive detection, with LODs of 316 and 60 CFU/mL for colorimetric and fluorescent detection, respectively. Notably, the fluorescent mode provided a self-calibrated and fivefold-improved sensitivity over colorimetric detection. Systematic results also revealed that the proposed dual-mode method exhibited high specificity and applicability for milk, egg white, and chicken meat samples, serving as a promising tool for real bacterial sample testing. As a result, the innovative dual-mode detection method showed new insights for the detection of other pathogens.
Funder
National Natural Science Foundation of China
Subject
Plant Science,Health Professions (miscellaneous),Health (social science),Microbiology,Food Science
Reference49 articles.
1. Qiu, S., Liu, B., Leng, Y., Fox, E., Zhou, X., Yan, B., Sang, X., Long, K., Fu, Y., and He, X. (2023). A label-free fiber ring laser biosensor for ultrahigh sensitivity detection of Salmonella Typhimurium. Biosens. Bioelectron., 234. 2. Coupling bifunctional nanozyme-mediated catalytic signal amplification and label-free SERS with immunoassays for ultrasensitive detection of pathogens in milk samples;Li;Anal. Chem.,2023 3. Capture, concentration, and detection of Salmonella in foods using magnetic ionic liquids and recombinase polymerase amplification;Hice;Anal. Chem.,2019 4. Magnetosome-anti-Salmonella antibody complex based biosensor for the detection of Salmonella typhimurium;Sannigrahi;Mater. Sci. Eng. C,2020 5. Guan, Z., Sun, Y., Ma, C.-B., Lee, J.J., Zhang, S., Zhang, X., Guo, Z., and Du, Y. (2023). Dual targets-induced specific hemin/G-quadruplex assemblies for label-free electrochemical detection capable of distinguishing Salmonella and its common serotype in food samples. Biosens. Bioelectron., 236.
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