Wang_2021_J.Hazard.Mater_403_123921

A dual-function cellulose nanofiber (CNF)-based bionic biosensor with good biocompatibility was developed for detecting Ag(+) and acetylcholinesterase (AChE) by grafting deoxyribonucleic acid (DNA) onto CNF. The Ag(+) ions captured by the biosensor acted as recognition sites for the detection of AChE. The CNF-based bionic biosensor (CNF-DNA) could detect Ag(+) concentrations as low as 10(-6) nM in the presence of interference metal ions (Hg(2+), Ba(2+), Cd(2+), Mg(2+), Mn(2+), Pb(2+), and Zn(2+)). DNA-template silver nanoclusters (DNA-AgNCs) were formed on the surface of CNF-DNA during the detection of Ag(+) (CNF-DNA-AgNCs). This new strategy yielded CNF-DNA-AgNCs through the adsorption of Ag(+) ions onto the cytosine base of the single-stranded DNA in CNF-DNA without the use of any additional reducer. Meanwhile, the CNF-DNA-AgNCs exhibited excellent sensitivity and selectivity for trace levels (0.053 mU/mL) of AChE in the presence of interference reagents. The novel strategy proposed in this paper may establish a foundation for further research on DNA-template AgNCs for developing biosensors and biomarkers for in vivo and in vitro detection.