Rapid Detection of Tetrodotoxin Using Surface-Enhanced Raman Spectroscopy and Fe{sub 3}O{sub 4}/SiO{sub 2}/Au Gold/Magnetic Nanoparticles
- Ocean College, Zhejiang University of Technology, Department of Food Science and Technology (China)
Fe{sub 3}O{sub 4} nanoparticles were first modified with tetraethoxylsilane to form Fe{sub 3}O{sub 4}/SiO{sub 2} nanoparticles, followed by the addition of 3-aminopropyltriethoxysilane and 3-thiolpropyltriethoxysilane to introduce –NH{sub 2} and –SH groups to the surface of Fe{sub 3}O{sub 4}/SiO{sub 2} nanoparticles. Gold nanoparticles were further assembled on the surface of Fe{sub 3}O{sub 4}/SiO{sub 2} via the electrostatic adsorption of –NH{sub 2} and the Au–S bond to produce stable core–shell Fe{sub 3}O{sub 4}/SiO{sub 2}/Au gold/magnetic nanoparticles. These Fe{sub 3}O{sub 4}/SiO{sub 2}/Au gold/magnetic nanoparticles were characterized by a variety of techniques such as transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX), and afterwards conjugated with tetrodotoxin antibodies (Ab) and used as a Raman active substrate (Fe{sub 3}O{sub 4}/SiO{sub 2}/Au–Ab) with Rhodamine B (RhB)-labeled tetrodotoxin antibody as a Raman reporter (Ab–RhB). Upon mixing these reagents with tetrodotoxin (TTX), a sandwich complex [Fe{sub 3}O{sub 4}/SiO{sub 2}/Au–Ab···TTX···Ab–RhB] was generated due to the specific antibody–antigen interactions. The immunocomplex was subsequently separated by an externally applied magnetic source and concentrated into a pellet point, where the laser interrogation of the pellet produced a strong signal characteristic of RhB. The logarithmic intensity of the signal was found to be proportional to the concentration of TTX with a limit of detection of 0.01 μg/mL and a detection linearity range of ~ 0.01–0.5 μg/mL. The established method eliminates the complicated procedures of traditional centrifuging, column separation, and incubation and achieves a rapid detection of tetrodotoxin with improved detection sensitivity.
- OSTI ID:
- 22810112
- Journal Information:
- Journal of Applied Spectroscopy, Journal Name: Journal of Applied Spectroscopy Journal Issue: 1 Vol. 85; ISSN 0021-9037
- Country of Publication:
- United States
- Language:
- English