Development of Colorimetric Sensor with Zinc Oxide Nanoparticles for Rapid Detection of Aflatoxin B1 in Rice

Aflatoxin B1 in food is most toxic to humans and mammals, classified as a Group I carcinogen by IARC. The work reports the development of colorimetric aflatoxin detection using ZnO nanoparticles (Nps) and curcumin composite prepared in 1:2 ratios. Structural, morphological and optical studies performed to optimize the detection limit. XRD revealed the wurtzite structure of ZnO Nps (20 nm) synthesized by aqueous solution method. With the increase of AFB1 (0-36 ppb) in rice sample, colorimetric study indicated a change from red to yellow and absorbance peak intensity increase at λ=461 nm. 0.25µL sample of ZnO Nps (0.5mg/ml) added with curcumin dye (1mg/ml) at ambient conditions used as a sensing material for the development of colormetric sensor with a detection limits of 11 ppb. This may be due to steric electrostatic binding of phenolate anions with the oxidized curcumin in the presence of ZnO Nps. Results were validated with HPLC.