Detection of Aflatoxin B₁ Based on a Porous Anodized Aluminum Membrane Combined with Surface-Enhanced Raman Scattering Spectroscopy

• Main Authors: Yanting Feng, Lei He, Ling Wang, Rijian Mo, Chunxia Zhou, Pengzhi Hong, Chengyong Li
• Format: Article
• Language: English
• Published: MDPI AG 2020-05-01
• Series: Nanomaterials
• Subjects: surface-enhanced Raman scattering (SERS); Ag nanoparticles; porous anodized aluminum membrane; Aflatoxin B₁
• Online Access: https://www.mdpi.com/2079-4991/10/5/1000

An Aflatoxin B₁ (AFB₁) biosensor was fabricated via an Ag nanoparticles assembly on the surface of a porous anodized aluminum (PAA) membrane. First, the Raman reporter 4-Aminothiophenol (4-ATP) and DNA (partially complementary to AFB₁ aptamer) were attached to the surface of Ag nanoparticles (AgNPs) by chemical bonding to form a 4-ATP-AgNPs-DNA complex. Similarly, the surface of a PAA membrane was functionalized with an AFB₁ aptamer. Then, the PAA surface was functionalized with 4-ATP-AgNPs-DNA through base complementary pairing to form AgNPs-PAA sensor with a strong Raman signal. When AFB₁ was added, AgNPs would be detached from the PAA surface because of the specific binding between AFB₁ and the aptamer, resulting in a reduction in Raman signals. The detection limit of the proposed biosensor is 0.009 ng/mL in actual walnut and the linear range is 0.01–10 ng/mL. The sensor has good selectivity and repeatability; it can be applied to the rapid qualitative and quantitative detection of AFB₁.