Abstract
Here, we compared the performance of the APTES+Probe biosensor for DNA detection with and without Tween-20 at various time intervals. To determine the sensitivity and specificity of the biosensor, the biosensor response was examined in the presence of complementary as well as mismatched DNA. The first reading indicated a 2.97 E-08 A for a sample of APTES+Probe after 10 minutes, then increased to 3.10 E-08 A for complementary DNA, and then decreased back down to 2.50 E-08 A for mismatched DNA. In these experimental conditions, current increased to 4.10E-08 A with the addition of Tween-20. Current for APTES+Probe also decreased with time to 4.71E−09 A at 60 min. The decrease in current was from 3.10E-08 A to 4.90E-09 A for complementary DNA and from 4.50E-09 A to 2.50E-08 A for matched DNA after 20 min of incubation, respectively, and the same incubation in Tween-20 showed the dropping, which had decreased the current values achieved from 10 min 4.10E-08 A to 30 min 5.42E-09 A, respectively. The results indicate that Tween-20 can improve the sensitivity (to complementary DNA) initially but reduce the response to the mismatched DNA (low response to most of them). Tween-20, for example, is beneficial to immunological detection in the initial applications but decreases its effectiveness as the application is prolonged, hinting at modulation possibilities [20]. These results suggest that Tween-20 has an effect on the performance of biosensors and show how useful this method could be for quickly and accurately finding DNA fragments.