A Colorimetric/Fluorescent Dual-Mode Aptasensor for Salmonella Based on the Magnetic Separation of Aptamers and a DNA-Nanotriangle Programmed Multivalent Aptamer.
Na MaMengni SunHanxing ShiLiangliang XueMin ZhangWenge YangYali DangZhaohui QiaoPublished in: Foods (Basel, Switzerland) (2023)
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.
Keyphrases
- sensitive detection
- loop mediated isothermal amplification
- quantum dots
- label free
- escherichia coli
- listeria monocytogenes
- living cells
- global health
- energy transfer
- public health
- multiple sclerosis
- fluorescent probe
- real time pcr
- gold nanoparticles
- nucleic acid
- climate change
- liquid chromatography
- molecularly imprinted
- transcription factor
- single molecule
- multidrug resistant
- gram negative
- mass spectrometry