Kestwal R.M.Bagal-Kestwal D.Chiang B.-H.2019-07-112019-07-11201500032670https://scholars.lib.ntu.edu.tw/handle/123456789/413280A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel-agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10-20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel-agarose-acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples. ? 2015 Elsevier B.V.AcetylcholinesteraseAgaroseCarbamatesFenugreek hydrogelGold nanoparticlesPesticidesjournal article10.1016/j.aca.2015.06.0042-s2.0-84940448270https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940448270&doi=10.1016%2fj.aca.2015.06.004&partnerID=40&md5=ee618b3f60dcf2be436552e899ac028b