One Tow Three Signal Amplification Strategies: Electrochemical Sensors Based on Highly Conductive Mxene-Au Nps and High Current Signal of Aupd Nps/Uio-66 for Tetracycline Detection

Abstract

Tetracycline (TET) is widely used as an antibiotic and is the most commonly used in animal husbandry and its affordability, minimal toxicity, and wide range of antibacterial action. Here, an electrochemical sensor for the detection of TET was constructed by combining MXene-Au NPs nanocomposites with the signaling probe MB/AuPd NPs/UiO-66, employing a variety of signal amplification techniques. one tow three signal amplification strategies, which corresponds to one aptamer being complementary to three DNA single strands. In the presence of the target, these three DNA single strands can be released, thus triggering a triple signal amplification effect and achieving the effect of “three birds with one stone”. The sensor was used as in situ grown gold nanoparticles (Au NPs) in MXene with a multilayer structure the electrode modification material. The current signal was significantly increased by a factor of 1.42 due to the large specific surface area and high electrical conductivity of the modified material. At the same time, AuPd NPs/UiO-66 loaded methylene blue (MB) was used as the signal probe, which combines the advantages of high current signal, stability and low cost. Ultimately in the presence of the target the signaling probe can be attached to the electrode in large numbers, which improves the signal response. Under the best conditions, the detection range of the sensor is 0.001 - 500 ng/mL, and the limit of detection (LOD) is 0.789 pg/mL.

Keywords: Electrochemistry, MXene-Au NPs, "Three birds with one stone", AuPd NPs/UiO-66, tetracycline