School of Food and Biological Engineering , Jiangsu University , Zhenjiang , Jiangsu 212013 , People's Republic of China.
J Agric Food Chem. 2018 Sep 26;66(38):10106-10112. doi: 10.1021/acs.jafc.8b03259. Epub 2018 Sep 13.
A reagentless and single-step electrochemical aptasensor with separation-free fashion and rapid response is developed for the Hg assay in dairy products. Herein, the sensing strategy is established on Hg-induced structural transition of the methylene-blue-tagged single-stranded DNA (ssDNA) from a flexible manner to rigid hairpin-shaped double-stranded DNA (dsDNA), generating an improved peak current for the Hg assay with a detection limit of 0.62 fM. Importantly, the best signal-to-noise ratio value can be obtained by exploiting Au flowers as sensing material and the optimal ssDNA concentration. The proposed sensor also exhibits high selectivity as a result of the specific thymine-Hg-thymine (T-Hg-T) coordination chemistry and can be applied to detect Hg in dairy products. With the use of the electric "signal-on" switch, the electrochemical aptasensor has the advantages of simplicity, ease of operation, and high sensitivity and specificity, offering a promising method to assess the safety of dairy products polluted with Hg.
一种无需试剂且一步到位的电化学适体传感器，具有无需分离的时尚设计和快速响应功能，可用于乳制品中汞的检测。在此，传感策略是基于汞诱导的亚甲基蓝标记的单链 DNA（ssDNA）从灵活方式到刚性发夹状双链 DNA（dsDNA）的结构转变建立的，从而产生了用于汞检测的改进的峰电流，检测限为 0.62 fM。重要的是，通过利用 Au 花作为传感材料和最佳的 ssDNA 浓度，可以获得最佳的信噪比值。由于特异性的胸腺嘧啶-汞-胸腺嘧啶（T-Hg-T）配位化学，该传感器还表现出高选择性，可用于检测乳制品中的汞。通过使用电“信号开启”开关，电化学适体传感器具有简单、易于操作以及高灵敏度和特异性的优点，为评估受汞污染的乳制品的安全性提供了一种有前途的方法。
