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Updated: Oct 13, 2025
Surface-enhanced Resonance Raman Scattering Nanoprobe Ratiometry for Detecting Microscopic Ovarian Cancer via Folate Receptor Targeting
Published on: March 25, 2019
Gold@silver nanodumbbell based inter-nanogap aptasensor for the surface enhanced Raman spectroscopy determination of
Xiaoyuan Ma1, Baoyi Shao2, Zhouping Wang1
1State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, PR China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, PR China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, 214122, PR China.
Abstract:
Here, a plasmonic nanogap structure was fabricated with its specific surface enhanced Raman spectroscopy (SERS) effect to construct an aptasensor for the sensitive detection of ochratoxin A (OTA). Gold nanorod (AuNR) were synthesized first by seed-mediated method. Then, silver was reduced and grown on its surface. In the presence of glycine, Ag0 was preferred to grow at both ends of AuNR to form gold@silver nanodumbbell (Au@AgND). The thiolated OTA aptamer and its complementary sequence were modified on Au@AgND respectively using Ag-SH bond. Under the base complementary pairing principle, Au@AgND assembly formed with certain inter distances. The inter-nanogap structure generated more hot spots which enhanced the Raman signal of 4-hydroxybenzoic acid (4-MBA) immobilized on Au@AgND. When OTA was present, the aptamer preferentially combined to OTA and the Au@AgND assembly disintegrated. Thus, the SERS signal of 4-MBA decreased. Under the optimal conditions, the OTA concentrations were inversely proportional to SERS signal. The linear range was 0.01 ng/mL-50 ng/mL and the limit of detection (LOD) was 0.007 ng/mL. The method can be successfully applied to the detection of real sample (beer/peanut oil).
