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

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.