Aptamer-Modified
Porous Anodized Aluminum Substrate
for Rapid and Ultrasensitive Detection of Tetracycline via Surface
Enhanced Raman Spectroscopy Couple with Electric Field Enrichment
posted on 2023-11-09, 16:40authored byZhenqing Dai, Jiayuan He, Fangmei Zhou, Tingting Lai, Guangzheng Jiang, Kang Wang, Chengyong Li, Yuqiang Yang
Tetracycline (TC) has broad-spectrum antimicrobial activity
and
is low cost and widely used in animal disease treatment drugs and
feed additives. However, the misuse of tetracycline causes serious
damage to ecosystems and poses a major threat to human health. Therefore,
the development of rapid and ultrasensitive TC detection methods is
of great significance for the effective monitoring and prevention
of TC pollution. Here, a surface enhanced Raman spectroscopy (SERS)
sensor combined with electric field enrichment technology was developed
for rapidly quantitative testing of TC. The SERS sensor was constructed
by introducing Ag nanoparticles (AgNPs) and a Raman probe (4-aminothiophenol,
4-ATP) on the porous anodized aluminum (PAA) membrane through hybridization
of aptamer-2 (Apt-2) with aptamer-1 (Apt-1). In the presence of TC,
the SERS tags (4-ATP/AgNPs/Apt-2) dissociate from this sensing platform,
attributed to the stronger specific binding of TC to Apt-1, leading
to a significant decrease in the Raman signal, which enables indirect
quantitative analysis of TC. Based on the ion current property of
the composite PAA membrane and the high activity and specificity of
the SERS substrate, TC can be rapidly enriched in 1 min by electric
field enrichment technology and identified by potable Raman spectrometer
in 3 min. The improved SERS sensor allows for a real-time response
to 1 fg/mL–1 ng/mL TC, and the limit of detection (LOD) is
1 fg/mL. More importantly, the SERS sensor can be used to detect TC
in real food samples (such as milk and shrimp) and has excellent performance.
The sensing strategy is very promising for mitigating food security
risk.