Биосенсоры и биоэлектроника

Electrochemical-Nucleic Acid Detection with Enhanced Specificity and Sensitivity

Abstract

Aldin Malkoc, Edgar Sanchez, Michael R Caplan and Jeffrey T La Belle

Development of a rapid and label-free Electrochemical Impedance Spectroscopy (EIS) biosensor for nucleic acid detection based on sensitivity and specifies was proposed to fill the technology gap between rapid and portable detection of DNA sequences. Current biosensors have inherent limitations to sensitivity and specificity due to the monovalent character of the detection method. These limitations were significantly improved upon by constructing cooperative probes, called Tentacle Probes™ (TP), which utilize divalent binding to achieve both high sensitivity as well as extremely high specificity. Immobilization of Tentacle Probe onto gold disk electrode produced statistical significance, with p<3.0*10-13. Tentacle Probe with EIS detection was able to detect a difference between the B. AnthracisgyrA gene and B. Cereus gyrA Single Nucleotide Polymorphism sequence at a lower limit of detection of 20nM. Furthermore, B. Cereus gyrA is a common soil bacterium that causes false positives for B. AnthracisgyrA. This method of detection is current a model system for DNA detection; other genes could be detected with this system. With the potential to be transformative by providing a platform technology for both DNA and protein detection with high sensitivity this system offers extremely low rates of false positives. There is a high capacity for the technology to be multiplexed for high-throughput applications or quick diagnostic tests for medical purposes. Thus, the biomarker development will also have the potential to be assessed through noninvasive methods.