A comparison of the performance of molecularly imprinted polymer nanoparticles for small molecule targets and antibodies in the ELISA format

Abstract

Here we show that molecularly imprinted polymer nanoparticles, prepared in aqueous media by solid phase synthesis with immobilised L-thyroxine, glucosamine, fumonisin B2 or biotin as template, can demonstrate comparable or better performance to commercially produced antibodies in enzyme-linked competitive assays. Imprinted nanoparticles-based assays showed detection limits in the pM range and polymer-coated microplates are stable to storage at room temperature for at least 1 month. No response to analyte was detected in control experiments with nanoparticles imprinted with an unrelated template (trypsin) but prepared with the same polymer composition. The ease of preparation, high affinity of solid-phase synthesised imprinted nanoparticles and the lack of requirement for cold chain logistics make them an attractive alternative to traditional antibodies for use in immunoassays.

Figure 1

Structures of the analytes used as templates in this study: (a) fumonisin B2, (b) glucosamine, (c) l-thyroxine, (d) biotin.

Figure 2

(Left) Schematic representation of nanoMIPs synthesis and competitive enzyme-linked assay; (Right) TEM image of nanoMIPs imprinted with l-thyroxine, scale bar = 200 nm.

Figure 3

Calibration plots determined in enzyme-linked competitive assay formats for: l-thyroxine with (a) l-thyroxine-imprinted polymer nanoparticles (MIP) or trypsin-imprinted particles (NIP) or (b) monoclonal antibody (mAb) for l-thyroxine; glucosamine with (c) glucosamine-imprinted polymer nanoparticles (MIP) or trypsin-imprinted particles (NIP) or (d) polyclonal antibodies (pAb) for glucosamine; fumonisin B2 with (e) fumonisin B2-imprinted polymer nanoparticles (MIP) or (f) monoclonal antibodies (mAb) for fumonisin B2; biotin with (g) biotin-imprinted polymer nanoparticles (MIP) or (h) with polyclonal antibodies (pAb) for biotin. Error bars represent ±1 standard deviation and are for experiments performed in triplicate. Data for biotin-MIPs (g) is also included in a report where the effect of template size on aqueous solid-phase imprinting was investigated, (see above).