Engineered Co₃O₄ nanoboxes boost luminol chemiluminescence for selective Mn²⁺ sensing

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Chemiluminescence (CL) offers sensitive detection but traditional methods like luminol/H2O2 have low efficiency.
• Nanozymes are explored to enhance CL sensitivity, with spinel oxides showing potential but underutilized in CL.
• Trace toxic metal detection requires highly sensitive and cost-effective analytical tools.

Purpose of the Study:

• To synthesize novel Co3O4 nanoboxes (NBs) for improved chemiluminescence.
• To investigate the peroxidase-like activity of Co3O4 NBs in the luminol/H2O2 system.
• To develop a sensitive method for detecting manganese ions (Mn2+) using the enhanced CL system.

Main Methods:

• A self-templating ZIF-67 MOF precursor was etched and thermally annealed to create Co3O4 NBs.
• The synthesized Co3O4 NBs were characterized for their catalytic activity.
• The luminol/H2O2 CL system was optimized with Co3O4 NBs for Mn2+ detection.

Main Results:

• Co3O4 NBs were successfully synthesized via a simple chemical etching and annealing process.
• The Co3O4 NBs exhibited significant peroxidase-like activity, boosting luminol/H2O2 CL by 670-fold.
• Enhanced CL signals were attributed to improved H2O2 adsorption and reactive oxygen species generation.
• Mn2+ ions effectively quenched the CL signal, enabling detection from 50 nM to 5 µM with a 2.5 nM limit of detection.

Conclusions:

• Co3O4 NBs are efficient nanozymes for enhancing luminol/H2O2 chemiluminescence.
• The developed method provides a highly sensitive and selective approach for Mn2+ detection.
• This research highlights the potential of spinel-type oxides in advanced analytical chemiluminescence applications.