Ultrasensitive SERS aptasensor for the detection of oxytetracycline based on a gold-enhanced nano-assembly.
This paper investigated a new detection method of oxytetracycline (OTC) in aquatic products with ultrasensitive detection limit. The method was constructed on the basis of raman hot spot between gold nanoparticles (AuNPs) (13nm and 80nm diameter respectively) linked by an DNA sequence. The DNA sequence combined with the OTC aptamer including its complementary sequence as well as a stem-loop structure. The raman signal molecule (4-MBA) was modified at the surface of 13nm AuNPs. After the exposure of OTC, the aptamer sequence was preferentially combined with OTC and partially dehybridized with its complementary sequence which led the 13nm AuNPs to get more closer to the 80nm AuNPs. The raman intensity was thus increased for the more enhanced hot spot generated. Under the optimal experimental conditions, the SERS signal was positively related to the OTC concentration with a wide working range of 4.60×10-2-4.60×102fg/mL and the limit of detection (LOD) was as low as 4.35×10-3fg/mL. The recovery rates of fishmeal ranged from 91.29-110.98%. The specificity of this method was further examined, and the results showed that the AuNPs based aptasensor was highly selective. This developed ultrasensitive aptamer-based SERS detection platform suggested that it may be a promising strategy for a variety of sensing applications.
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Fanwei
F
Meng
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Xiaoyuan
X
Ma
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Nuo
N
Duan
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Shijia
S
Wu
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Yu
Y
Xia
State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address: wangzp@jiangnan.edu.cn.
Zhouping
Z
Wang
State Key Lab Meat Processing & Quality Control, Yurun Group, Nanjing 210041, Jiangsu, China.
Baocai
B
Xu
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D010118:Oxytetracycline / Q000032:analysis*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D052157:Aptamers, Nucleotide; D006046:Gold; D010118:Oxytetracycline
Aptasensor; Gold-enhanced; Nano-assembly; Oxytetracycline; SERS