Dual Enzyme Mimetic Activities of CuBiZr@PAH Nanocomposites for Enzyme Free Colorimetric Detection of Glucose and Uric Acid

Novel colorimetric sensors are designed for ultrasensitive and highly efficient detection of glucose and uric acid (UA) based on dual enzyme mimetic activities of CuBiZr@PAH nanocomposite (P1). The colorimetric sensor utilizes the glucose oxidase-like (GOx) and peroxidase-like (POD) activities of P1 to detect glucose and UA. When P1 is present in a solution of glucose and 3,3′5,5′-tetramethylbenzidine (TMB), P1 catalyzes two cascade reactions: one between glucose and O₂ and the other between TMB and as-generated hydrogen peroxide (H₂O₂). The latter reaction provides visual results of glucose analysis with a LOD of 0.04 mm in the range of 0–40 mm in human serum samples. Furthermore, when P1 is present in a solution of UA, TMB, and H₂O₂, P1 catalyzes cascade reactions: one reaction between UA and H₂O₂ and the other reaction between TMB + H₂O₂. UA suppresses the POD-like activity of P1 to detect UA with a LOD of 0.15 µm in the range of 10 µm–1.5 mm in urine samples. P1 exhibits dual enzyme mimetic activities for efficient detection of glucose and UA in real samples. The as-designed colorimetric sensors display high selectivity, good stability, excellent specificity, and desirable practicability for detecting glucose and UA in real samples.