Two-dimensional titanium carbide (MXene)-based solid-state electrochemiluminescent sensor for label-free single-nucleotide mismatch discrimination in human urine

As a representative member of two dimensional MXenes, the OH-terminated Ti3C2 (Ti3C2Tx) is metallically conducting, with electrical conductivity as high as 6500 S cm(-1). In addition, the terminated groups such as -OH make Ti3C2 negatively charged. Based on these superiorities, Ti3C2Tx MXene was herein used to form composite film with Nafion for the solid-state ECL sensor construction for the first attempt. The utilization of Ti3C2Tx not only endow the composite film with much higher conductivity, but also enhance the adsorption amount of Ru(bpy)(3)(2+) on the electrode surface. The as-proposed sensor was investigated using tripropylamine as a representative ECL coreactant and low detection limit (S N-1 >= 3) of 5 nM was achieved. It also exhibited much excellent reproducibility (relative standard deviations of (0.69% for 107 continuous cycles) and long-term stability (about 90% of its preliminary ECL intensity can be retained after intermittent use over a 90-day period). In addition, the application potential of the as-prepared sensor was verified by the single-nucleotide mismatch discrimination in human urine. As a result, the as-prepared sensor was proved to be with the superiorities of easy-operation, simplicity, long-term stability, and applicability. (C) 2018 The Author( s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.