Recently, the biochemical analysis technology innovation team for food safety of SHOU, headed by associate research fellow Yan Juan from the College of Food Science and Technology, has published a new research achievement on Biosensors & Bioelectronics, a top internationaljournal in the sensor field (with a latest 2019 IF of 9.518, ranked top 10% in terms of ESI). This paper is entitled “Terminal deoxynucleotidyltransferase (TdT)-catalyzed homo-nucleotides-constituted ssDNA: Inducing tunable-size nanogap for core-shell plasmonic metal nanostructure and acting as Raman reporters for detection of Escherichia coli O157:H7 (https://doi.org/10.1016/j.bios.2019.111419). The first author and corresponding author of this paper are Master student Zhou Yangyang and associate research fellow Yan Juan, respectively.

As one of the main food-borne pathogenic bacteria, escherichia coli O157:H7 frequently causes serious diseases such as hemolytic uremic syndrome and bloody diarrhea or even death. In this regard, existing bacterial detection methods are restricted by their long detection time, complex pretreatment, low sensitivity, etc. Surface-enhanced Raman scattering (SERS) is nowadays one of the most sensitive surface detection techniques, which detects the structural information of materials at molecular level and is extensively applied in environmental monitoring, food safety, clinical test, disease diagnosis, and many other fields. The research team headed by associate research fellow Yan Juan used the core-shell plasmonic metal nanostructure prepared from TdT-catalyzed homo-nucleotides-constituted ssDNA for SERS-based detection research. The long-chain DNA acquired through DNA amplification in the core-shell could not only tune nanogap size but also serve as Raman reporters of SERS-based detection. In the specific Raman imaging of escherichia coli O157:H7, the lower limit of detection reached two bacteria, and the recovery rate in real food samples was 98.1%-105.2%.

This study was funded by Natural Science Foundation of China (NSFC), the program for cultivation of young and middle-aged talents of the College of Food Science and Technology, etc. Led by the research team headed by associate research fellow Yan Juan from the College of Food Science and Technology, it was completed through collaboration with Professor Zhang Weijia from Fudan University, research fellow Wang Lihua from Shanghai Institute of Applied Physics (SINAP, CAS), etc.