Nb4C3Tx (MXene)/Au/DNA Aptasensor for the Ultraselective Electrochemical Detection of Lead in Water Samples

Abstract An electrochemical aptasensor was designed for the ultraselective and sensitive detection of Pb 2+ by using lead‐specific binding DNA oligonucleotide as the molecular recognition element on Au nanoparticles/Nb 4 C 3 T x MXene (Au@Nb 4 C 3 T x ) modified electrode. The Au@Nb 4 C 3 T x is conjugated with thiol‐modified lead‐binding DNA through the Au−S bond. The DNA−Au@Nb 4 C 3 T x modified glassy carbon electrode exhibited ultrahigh selectivity and enhanced response towards the detection of Pb 2+ with a detection limit of 4 nM and linear range of 10 nM to 5 μM. This work has proved the possibility of using Nb 4 C 3 T x as a robust immobilization platform for DNA oligonucleotides towards different environmental sensing and biomedical applications.