Microwave-assisted synthesis of fish bone-like CuBr@Au microcrystals and their electrochemical sensor performances

An electrochemical sensor with low cost, multifunctionality, wide detection range and high sensitivity were desirable. This work provided a novel perspective for the design of low-cost sensor materials with enhanced performance. The sensor performances of cost-effective CuBr were optimized by morphology optimization and surface modification. For the first time, a microwave-assisted synthesis of fish bone-like CuBr was provided. The unique morphology increased the specific surface area, which enabled the fish bone-like CuBr a superior sensor performance. Compared to CuBr synthesized via traditional hydrothermal methods [CuBr(s)], bone-like CuBr by microwave-assisted method [CuBr(w)] demonstrated 3.28-folds sensitivity toward nitrite. To further enhance the sensitivity, we futher modified the CuBr surface with Au nanocrystals. The Au modification significantly accelerated the rate of electron transfer, thereby optimizing the nitrite sensor performances. The nitrite sensor sensitivity by CuBr(w) was enhanced by optimizing the Au loading rate, achieving a sensitivity up to 106.72 μA/mM·cm². As applied in the glucose sensor, the detection range by CuBr@Au(w)-7 % extended from 0 to 100.0 mM by chronoamperometric measurement was much wider than previous works. Considering the wide detection range in glucose concentration analysis, the CuBr@Au(w) was further utilized to accurately determine sugar concentrations in Pepsi Cola.