Detection of melamine in milk using molecularly imprinted polymers-surface enhanced Raman spectroscopy

Yaxi Hu; Shaolong Feng; Fang Gao; Eunice C Y Li-Chan; Edward Grant; Xiaonan Lu

doi:10.1016/j.foodchem.2014.12.051

Detection of melamine in milk using molecularly imprinted polymers-surface enhanced Raman spectroscopy

Food Chem. 2015 Jun 1:176:123-9. doi: 10.1016/j.foodchem.2014.12.051. Epub 2014 Dec 20.

Authors

Yaxi Hu¹, Shaolong Feng¹, Fang Gao², Eunice C Y Li-Chan¹, Edward Grant³, Xiaonan Lu⁴

Affiliations

¹ Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
² Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
³ Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
⁴ Food, Nutrition and Health Program, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada. Electronic address: xiaonan.lu@ubc.ca.

PMID: 25624214
DOI: 10.1016/j.foodchem.2014.12.051

Abstract

A novel biosensor combining molecularly imprinted polymers and surface-enhanced Raman spectroscopy (MIPs-SERS) determines melamine in whole milk. MIPs were synthesized by bulk polymerization of melamine (template), methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linking agent) and 2,2'-azobisisobutyronitrile (initiator). Static and kinetic adsorption tests validated the use of MIPs to efficiently separate and enrich melamine from whole milk. Silver dendrite nanostructure served as SERS-active substrate for signal collection. Principal component analysis and hierarchical cluster analysis segregated Raman signatures of whole milk samples with different melamine concentrations. Regression models showed a good linear relationship (R(2)=0.93) between the height of melamine SERS band (at 703cm(-1)) and melamine concentration in the range from 0.005mmolL(-1) to 0.05mmolL(-1). The limit of detection and limit of quantification were 0.012mmolL(-1) and 0.039mmolL(-1), confirming the high sensitivity of this biosensor to accurately determine melamine in whole milk. Simple sample pretreatment reduced full analysis time to determine melamine in whole milk to less than 20min.

Keywords: Chemometrics; Food adulteration; Melamine; Melamine (PubChem CID: 7955); Molecularly imprinted polymers; Raman spectroscopy; SERS.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Food Analysis / methods
Food Contamination
Milk / chemistry*
Molecular Imprinting / methods*
Polymers / chemistry
Solid Phase Extraction / methods*
Spectrum Analysis, Raman / methods*
Triazines / analysis
Triazines / chemistry*

Substances

Polymers
Triazines
melamine