Constructing a defect-rich hydroxide nanoenzyme sensor based on dielectric barrier discharge microplasma etching for...

In this work, a novel approach was designed to fabricate a defect-rich hydroxide nanoenzyme sensor based on transition metal cobalt derived from metal-organic framework (MOF). Facile preparation was realized by room-temperature reaction and chemical etching via dielectric barrier discharge (DBD) microplasma, which possesses great chemical reactivity to obtain defect-rich and ultrathin structures. The prepared cobalt hydroxide (Co(OH)₂) emerges with superior catalytic activity for thiamine hydrochloride (TCL) and hydrogen peroxide (H₂O₂) assay. The linear ranges were 0.0006 mM to 2.75 mM for TCL detection and 0.001 mM to 5.5 mM for H₂O₂ detection with low limit of detections (LODs) of 14 nM and 93 nM, respectively. Meanwhile, the as-prepared sensor provides excellent long-term durability (>25 days), as well as high sensitivity (12730 μA mM^-1cm^-2 and 5199.3 μA mM^-1 cm^-2) for TCL and H₂O₂ assay. TCL in serum samples has been detected with satisfactory results by the proposed material, while the H₂O₂ in Hela cells was also successfully measured. The developed sensor provides several advantages including simplicity, high sensitivity, and efficient preparation.