Redox-mediated dsDNA-dye photooxidase mimic enable catalytic oxidation of 3,3',5,5'-tetramethylbenzidine by dissolved O at neutral pH for improved biosensing.

Catalytic oxidation of 3,3',5,5'-Tetramethylbenzidine (TMB, an excellent chromogenic substrate) at neutral pH is critically important for amplified bioanalysis. Although some nanozymes exhibited the peroxidase activity at neutral pH, it is difficult to modulate their activity for homogeneous detection of biomolecules. In this work, we developed a redox-mediated dsDNA-dye photooxidase mimic that enables catalytic oxidation of TMB by dissolved O at neutral pH for improved biosensing.

Valence fixable ferrozine gel rod combined with smartphone for facile determination of redox-active Fe in environmental water.

Ferrous ion (Fe) can indicate the redox situation of water and also plays an important role in maintaining the ecological balance of water bodies. However, due to the redox-active property of Fe, it is still a huge challenge to sensitively and accurately determine Fe especially in interstitial water. Herein, we prepared a ferrozine gel rod for valence fixation during sampling and subsequent smartphone-based detection of Fe.