Ratiometric Electrochemical Sensing Strategy for the Ultrasensitive Detection of Telomerase Activity

Abstract

We fabricated a ratiometric electrochemical strategy for the ultrasensitive analysis of telomerase activity. The hairpin DNA probe labeled with methylene blue (MB) tags at its 5' termini is firstly immobilized on the gold electrode. It then hybridizes with the telomerase substrate primer labeled with ferrocene (Fc) tags. With the telomerase-catalyzed reaction, a repeating sequence of (TTAGGG) n is generated, which is able to trigger the conformational transduction of the hairpin DNA probe. Consequently, MB tags are released from the electrode surface and the oxidation peak current (I MB ) decreases. Meanwhile, the Fc signal remains stable and the peak current (I Fc ) can be used as the internal control, which improves the signal stability. This smart design allows reliable target recognition and the obtained results assure excellent analytical performances.

Ratiometric Electrochemistry: Improving the Robustness, Reproducibility and Reliability of Biosensors

“…A dynamic range was reported of 2 × 10 2 to 2 × 10 6 HeLa cell mL −1 with a calculated LOD of 27 HeLa cell mL −1 . A biosensor developed by Miao et al used a simpler strategy for the detection of telomerase (Figure 9b) [31]. A 5 -MB-labelled strand was immobilised onto the AuE surface and adopted a hairpin conformation.…”

Test Strip Platform Spin-Off for Telomerase Activity Detection: Development of an Electrochemical Biosensor

“…Some claim incredible detection limits 23 − 29 and proposed very novel processes. 29 , 30 However, some of them involve complex procedures, 23 others with a relative complexity of the output signal (i.e., SERS methods), 24 , 27 the use of sophisticated instruments that will represent a challenge when translating from the laboratory bench to the physician’s office as a tool for detection, diagnosis, and monitoring cancer. Others do not report results with complex samples, such as biological samples (tissues samples).…”

A ratiometric electrochemical strategy based on Fe (iii) and Pt (iv) for immobilization-free detection of Escherichia coli

“…Finally, the gained current ratio change can not only be used to validate the electrode function, but also to present the concentration of the target simply and susceptibly. 28 Briey, dual-signal ratiometric measurements show great promise at the chemotherapeutic, cellular and animal levels. [29][30][31] Therefore, the application of a double signal ampli-cation strategy and ratiometric electrochemical method can further improve the detection sensitivity and selectivity of the sensor.…”