Facile and sustainable synthesis of zinc cobaltite nanoparticles from Laportea interrupta plant extract for multifunctional applications

Metal oxide nanoparticles synthesized via environmentally benign green routes continue to advance nanotechnology owing to their attractive catalytic and biological properties, and the development of multifunctional nanocomposites based on such materials has recently attracted considerable attention. Nanomaterials capable of preventing or delaying blood coagulation are being explored as alternatives to conventional anticoagulants. They are also employed as supports for enzyme immobilization, enhancing protease and amylase activity while improving enzyme stability and recyclability. Herein, we report a cost-effective green synthesis of zinc cobaltite (ZnCo₂O₄, ZC) nanoparticles using Laportea interrupta (Hen's Nettle) leaf extract as fuel. The synthesized nanoparticles were characterized using XRD, FT-IR, UV-DRS, SEM, EDAX, TEM, and PL spectroscopy. The nanoparticles exhibited a pronounced anticoagulant effect, prolonging the prothrombin time (PT) from 17 to 25 s and the activated partial thromboplastin time (APTT) from 52 to 120 s. Amylase activity was activated at a low concentration (0.63 µmol/min/ml), while protease activity increased by 18 units with increasing ZC concentration. Electrochemically, at an optimized ratio and a current density of 0.1 mA in 2 M KOH, the ZC nanoparticles delivered a specific capacitance of 54.6 F/g and retained 92% of their initial capacitance after 2000 cycles. These findings demonstrate that green-synthesized ZnCo₂O₄ nanoparticles are promising candidates for both electrochemical and biomedical applications.