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Updated: Sep 20, 2025
Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
A three-dimensional gold nanoparticles spherical signal array - enhanced dual-mode aptasensor for facile and
Li Wang1, Jingjing Kang2, Wei Pang3
1School of Public Health, the key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, 561113, China; Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Military Medical Sciences Academy, Academy of Military Sciences, Tianjin, 300050, China.
Abstract:
Ochratoxin A (OTA), a highly carcinogenic mycotoxin contaminating agricultural products, presents critical challenges to food safety and human health. Existing biosensors are predominantly limited to single-signal detection modes, which necessitates the development of more efficient and reliable dual-mode sensors to enhance anti-interference capabilities. Herein, a three-dimensional(3D) gold nanoparticles spherical signal array (AuNPs-SSA)-enabled dual-mode aptasensor that synergistically integrates fluorescence (FL) and surface-enhanced Raman scattering (SERS) detection was established. The aptasensor architecture employs polystyrene microparticles (PS) as scaffolds to organize 5-carboxyfluorescein (FAM)-ssDNA and 4-mercaptobenzoic acid (MBA)-functionalized AuNPs into a spatially optimized 3D spherical array with controlled interparticle distances. This aptasensor achieves structural stability through tunable interparticle AuNPs spacing, simultaneously a FL signal was amplified via maximized FAM-ssDNA loading, and SERS activity was enhanced via utilizing Raman "hot spots" generated by leveraging precisely engineered nanogaps. Through competitive binding between OTA and the AuNPs-SSA probe with aptamer-modified magnetic nanoparticles (MNPs-H0), the aptasensor enables simultaneous FL and SERS enhancement responses. Demonstrating superior sensitivity, the dual-mode system achieves linear detection across 102-107 fg/mL with ultralow limits of detection (21.87 fg/mL for FL and 17.06 fg/mL for SERS). Validation using spiked samples (peanuts, rice and beer) yielded recoveries of 90.44-108.11 % (FL) and 95.88-108.27 % (SERS), confirming practical reliability.
