A colorimetric sensing platform based on MOF-derived hollow Co, N co-doped C with dual-enzyme mimetic activity for the highly sensitive detection of hexavalent chromium
摘要
Hexavalent chromium (Cr(VI)) poses serious risks to human health and ecological environment due to its high toxicity and non-biodegradability. Therefore, developing highly sensitive detection methods for Cr(VI) is of significant importance. Here, a colorimetric sensing platform based on hollow cobalt and nitrogen co-doped porous carbon (H-Co, NPC) was proposed for the sensitive detection of Cr(VI). H-Co, NPC was synthesized by high-temperature calcination of a ZIF-8@ZIF-67 precursor, and it exhibited excellent peroxidase-like and oxidase-like activities. The hollow structure significantly enhances the accessibility of active sites and facilitates mass transport, while the co-doping of Co and N effectively improves electron transfer capability and substrate affinity. These synergistic effects make H-Co, NPC a promising candidate for colorimetric sensing applications. The sensing platform demonstrated excellent detection capabilities toward Cr(VI), including low detection limit (5 nM), wide linear range (0.015-1.5 µM), outstanding reproducibility and anti-interference ability. Moreover, it exhibited satisfactory detection performance of Cr(VI) in real samples. This work would provide new insights into the development of highly sensitive colorimetric sensing platforms.