Rapid and highly sensitive colorimetric biosensor for the detection of glucose and hydrogen peroxide based on nanoporphyrin combined with bromine as a peroxidase-like catalyst.

[Display omitted] • We developed a colorimetric biosensor to detect glucose and H 2 O 2. • The sensor is based on the peroxidase activities of nanoporphyrin and bromine. • This peroxidase activity is based on electron transfer of porphyrin and Br−. • The detection limits for glucose and H 2 O 2 were 0.15 and 0.5 μmol L−1. • Recovery ratios of spiked human serum and saliva samples were 100 % ± 10 %. Peroxidase is a popular amplifier of biosensor signals, but its application is limited by chemical instability and expensive purification. We developed a sensitive, novel colorimetric biosensor to detect glucose and hydrogen peroxide (H 2 O 2) using Zinc tetrakis (4-pyridinyl) porphyrin (ZnTPyP)-dodecyl trimethyl ammonium bromide (DTAB) nanoparticles (NPs) as peroxidase-like catalysts. ZnTPyP-DTAB NPs can oxidize colorless 3, 3', 5, 5'-tetramethylbenzidine to a blue product (652 nm) in the presence of H 2 O 2 via electron transport between porphyrin and bromine. This peroxidation mechanism was further verified using quantum chemical calculations. The detection limits of the colorimetric ZnTPyP-DTAB NP sensor were 0.15 and 0.5 μmol L−1 for glucose and H 2 O 2 , respectively, and the linear range was 3–70 and 8–50 μmol L−1, respectively. Recovery ratios of the biosensor in spiked human serum and saliva samples were 100 % ± 10 %. This simple method is robust, color stable, and reliable, thus providing an effective colorimetric biosensing platform for biomedical diagnosis. [ABSTRACT FROM AUTHOR]