A sandwich-type DNA electrochemical biosensor for hairpin-stem-loop structure based on multistep temperature-controlling method

Guolin Hong,^1,2,* Yinhuan Liu,^1,* Wei Chen,^3,5 Shaohuang Weng,^3,5 Qicai Liu,⁴ Ailin Liu,^3,5 Daoxin Zheng,¹ Xinhua Lin,<sup>3,5

1</sup>Department of Laboratory Medicine, The Fuzhou Second Affiliated Hospital of Xiamen University, Fuzhou, China; ²Department of Laboratory Medicine, Medical Technology and Engineering College of Fujian Medical University, Fuzhou, China; ³Department of Pharmaceutical Analysis, Pharmacy College of Fujian Medical University, Fuzhou, China; ⁴Department of Laboratory Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China; ⁵Nano Medical Technology Research Institute, Fujian Medical University, Fuzhou, China

^*Guolin Hong and Yinhuan Liu contributed equally to the present study

Abstract: A highly sensitive and selective method for amplified electrochemical detection for hairpin-stem-loop structured target sequences was developed based on the temperature regulation of DNA hybrids on a sandwich-type electrochemical DNA sensor. Multistep hybridization was applied to promote the hybridization efficiency of each section of sandwich structure. The results showed that both multistep and temperature-controlling hybridization techniques were both especially made to fabricate the sensor for the tendency of internal hybridization of target gene sequences. This strategy provides significantly enhanced hybridization efficiency and sequence specificity of electrochemical detection.

Keywords: sandwich-type biosensor, structured target, multistep temperature-controlling, DNA hybridization, tubercle bacillus