Boosted Sensor Performance by Surface Modification of Bifunctional rht-Type Metal-Organic Framework with Nanosized Electrochemically Reduced Graphene Oxide.

The surface and interface could be designed to enhance properties of electrocatalysts, and they are regarded as the key characteristics. This report describes surface modification of a bifunctional rht-type metal-organic framework (MOF, Cu-TDPAT) with nanosized electrochemically reduced graphene oxide (n-ERGO). The hybrid strategy results in a Cu-TDPAT-n-ERGO sensor with sensitive and selective response toward hydrogen peroxide (H2O2). Compared with Cu-TDPAT, Cu-TDPAT-n-ERGO exhibits significantly enhanced electrocatalytic activities, highlighting the importance of n-ERGO in boosting their electrocatalytic activity. The sensor shows a wide linear detection range (4-12 000 μM), and the detection limit is 0.17 μM (S/N = 3) which is even lower than horseradish peroxidase or recently published noble metal nanomaterial based biosensors. Moreover, the sensor displays decent stability, excellent anti-interference performance, and applicability in human serum and urine samples. Such good sensing performance can be explained by the synergetic effect of bifunctional Cu-TDPAT (open metal sites and Lewis basic sites) and n-ERGO (excellent conductive property). It is expected that rht-type MOF-based composites can provide wider application potential for the construction of bioelectronics devices, biofuel cells, and biosensors.