NH2-MIL-101(Fe) anchored onto nanoporous gold microelectrode: Highly sensitive electrochemical platform for simultaneously sensing of ascorbic acid and uric acid

Resolving the issue of poor conductivity and easy aggregation of MOFs is recognized as one important factor for their successful applications in electrochemical sensors and electrocatalysis. In this work, we propose an assembly of NH 2 -MIL-101(Fe) onto a nanoporous gold (NPG) microelectrode surface. The nanoporous gold could greatly improve the conductivity and reduce the aggregation of NH 2 -MIL-101(Fe). The proposed NH 2 -MIL-101(Fe)/NPG microelectrode was developed for the electroanalysis of ascorbic acid (AA) and uric acid (UA). It exhibited excellent electrochemical performance for the individual and simultaneous sensing of AA and UA in a 0.1 M PBS solution (pH 7.4). High sensitivities (2.03 μA μM −1 cm −2 for AA; 29.30 μA μM −1 cm −2 for UA) were achieved in the simultaneous analysis process. The improved electrochemical performance was attributed to the electrocatalytic properties and large specific surface area of NH 2 -MIL-101(Fe)/NPG, as well as the electrostatic interaction between NH 2 -MIL-101(Fe) and analytes. Moreover, the NH 2 -MIL-101(Fe)/NPG microelectrode was successfully used for the simultaneous detection of AA and UA in complicated environment (human sweat and advanced DMEM). This work shows great promise for the simultaneous detection of AA and UA and extends the applications of MOFs in electrochemical devices.