Electrochemical techniques for characterization of stem-loop probe and linear probe-based DNA sensors

Effects of DNA Probe Length on the Performance of a Dynamics‐based Electrochemical Hg(II) Sensor

“…ACV was first used to characterize the sensors . For all three sensors, in the absence of Hg(II), a large MB peak at ∼−0.31 V (vs. Ag/AgCl) was observed, confirming successful immobilization of the DNA probes (Figure ).…”

“…A more direct approach to detect Hg(II) has also been reported, Guerreiro et al . developed an E‐ION Hg(II) sensor that employs a similar signalling mechanism as the linear probe electrochemical DNA (E‐DNA) sensor . However, there is a critical aspect of the E‐ION Hg(II) sensor design that has not been previously explored, the effects of DNA probe length on the sensor response are not known.…”

Comparison of Mannose, Ethylene Glycol, and Methoxy-Terminated Diluents on Specificity and Selectivity of Electrochemical Peptide-Based Sensors

“…This trend is often seen with the linear probe electrochemical DNA (E-DNA) sensor and can be explained using a previously developed theory. [37][38][39][40][41][42][43] In brief, as the applied frequency approaches a critical value (i.e., "threshold" frequency) above which electron transfer can no longer keep pace with the rapidly oscillating potential, the peak current diminishes relative to the background current. 29,42,43 The AC frequency-dependent profiles suggest that the peptide probes assume a somewhat linear and unstructured conformation.…”

“…While the probe coverages shown in Table S2 are substantially lower than the coverages used in the E-DNA and electrochemical aptamer-based (E-AB) sensors, they are ideal for capturing large targets such as the Anti-p24 Ab. [4][5][6][39][40][41] We also evaluated the ET rate of MB before and after the addition of 70 nM Anti-p24 Ab and fitted the data to a previously reported model ( Figure S6). 29,42,43 We were not able to obtain a good fit for the C6-OH sensor, presumably because of the different conformations this peptide 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 14 probe can assume, resulting in a distribution of local redox environments and ET rates.…”

Methylene blue phosphoramidite for DNA labelling

“…These values were similar to the values reported in the literature. 12,54 The half-peak anodic potential value around 35 mV indicates that the redox process involves 2 electrons (theoretical values of 28.3 mV for a reversible two electrons process and 56.5 mV for one electron process) 53 and the observed negative shift of E 1/2 value (-110 mV) between pH 6.4 and pH 8 indicates that 2 protons are transferred during the electron transfer according Nernst Equation. The ∆E value was around 51 mV (pH 6.4) and 71 mV (pH 8), which appears to be higher than that of 4b (see Table S1 Supporting Information).…”