Colorimetric detection of putrescine and cadaverine in aquatic products based on the mimic enzyme of (Fe,Co) codoped carbon dots

A facile colorimetric method for rapid detection of putrescine (Put) and cadaverine (Cad) based on the peroxidase-like activity of (Fe,Co) codoped-CDs was developed. With the enzymatic hydrolysis by diamine oxidase (EC 1.4.3.6, DAO), Biogenic amines (BAs) were decomposed to produce -H2O2 which oxidizes 3,3',5,5'-tetramethyl-benzidine with the catalysis of ( Fe,Co)-codoped CDs. By means of principal component analysis, Put and Cad were differentiated from BAs and their total amounts were detected by measuring the spectral absorption at 652 nm with a linear range from 0.25 to 10 mg g(-1). The colorimetric method was applied to the detection of Put and Cad in various fish samples with a detection limit ((3 sigma/k, n = 9)) of 0.06 mg g(-1). Besides verifying with HPLC, the recoveries of the colorimetric method were also tested by spiking standards at three levels with the range of 98.2%-115.7%, indicating that the established colorimetric method was accurate and sensitive.

Automated summary

A facile colorimetric method based on the peroxidase-like activity of (Fe,Co) codoped-CDs was developed for rapid detection of putrescine and cadaverine. The enzymatic hydrolysis by diamine oxidase generated H2O2, which oxidized a substrate with the catalysis of (Fe,Co)-codoped CDs. The method showed high accuracy and sensitivity in detecting the target molecules in various fish samples.