Computational design of molecularly imprinted polymer for direct detection of melamine in milk

ABSTRACT

A novel protocol for use of molecularly imprinted polymer (MIP) in analysis of melamine is presented. Design of polymer for melamine has been achieved using a combination of computational techniques and laboratory trials, the former greatly reducing the duration of the latter. The compatibility and concerted effect of monomers and solvents were also investigated and discussed. Two novel open-source tools were presented which are the online polymer calculator from mipdatabase.com and the application of the Gromacs modelling suite to determine the ideal stoichiometric ratio between template and functional monomer. The MIP binding was characterised for several structural analogues at 1–100 μM concentrations. The use of divinylbenzene (DVB) as cross-linking polymer and itaconic acid as functional monomer allowed synthesis of MIP with imprint factor (IF) of 2.25 for melamine. This polymer was used in high-performance liquid chromatography (HPLC) for the rapid detection of melamine in spiked milk samples with an experimental run taking 7–8 min. This approach demonstrated the power of virtual tools in accelerated design of MIPs for practical applications.

KEYWORDS:

• Melamine
• milk
• molecularly imprinted polymer
• molecular modelling
• molecular dynamics

Funding

This research was supported by the Research Executive Agency (REA) of the European Union under grant agreement number PITN-GA-2010-264772 (ITN CHEBANA) and the Spanish Ministry of Economy MINECO (project CTQ2013-41577-P). M. del Valle acknowledges the support provided by the Catalonia program ICREA Academia.

Additional information

Funding

This research was supported by the Research Executive Agency (REA) of the European Union under grant agreement number PITN-GA-2010-264772 (ITN CHEBANA) and the Spanish Ministry of Economy MINECO (project CTQ2013-41577-P). M. del Valle acknowledges the support provided by the Catalonia program ICREA Academia.