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

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 (H2O2) 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 H2O2 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 mu mol L-1 for glucose and H2O2, respectively, and the linear range was 3-70 and 8-50 mu mol 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.

Automated summary

A sensitive and novel colorimetric biosensor was developed for detecting glucose and hydrogen peroxide, with high recovery rates in human serum and saliva samples, providing an effective biosensing platform for biomedical diagnosis.