Effective biocatalyst developed via genipin mediated acetylcholinesterase immobilization on rice straw derived cellulose nanofibers for detection and bioremediation of organophosphorus pesticide

This study aims to utilize cellulose nanofibers (CNFs) derived from rice straw to immobilize acetylcholinesterase (AChE) and their effective use as fluorescent sensor cum biocatalyst for sensing and degradation of chlorpyrifos (CPF) into 3,5,6-trichloro-2-pyridinol (TCP) and benign metabolites. AChE immobilized CNFs (AChE@CFs) exhibited excellent selectivity towards CPF in presence of other pesticides, amino acids and heavy metal ions with limit of detection as 90 nM. As compared to free enzyme, a better storage stability, higher endurance to change in pH and temperature and recyclability upto 20 cycles with 8% loss of activity was achieved. AChE@CFs effectively degraded CPF in 36 h. Kinetics of degradation revealed first order kinetics with rate constant of 0.0611 h−1 and half-life of 11.34 h, better than the reported studies leading to conclusion that AChE@CFs is efficacious catalyst for degradation of CPF, not reported hitherto.