Electrochemical detection of atrial natriuretic peptide-coated nanocarriers based on a molecularly imprinted polymer receptor thin film

Molecular imprinting polymers (MIPs) are biomimetic materials of great interest in the scientific and industrial fields for the development of innovative sensing strategies. Herein, we proposed a new sensing application by developing an electrochemical sensor using molecular imprinting (MI) technology for recognition of atrial natriuretic peptide (ANP) both as a free molecule in solution and attached to nanoparticle-based drug delivery systems (DDSs), aiming to provide fast and reliable information on the cell uptake of nanoparticles (NPs). As proof of concept, poly(lactic-co-glycolic acid) (PLGA) NPs were synthesized and used as nanocarriers for ischemic heart disease therapy were synthesized and then functionalized with ANP (named here as PLGA-NPs@ANP). The MIP receptor film was prepared by electrochemical polymerization of dopamine over the working area of a gold screen-printed electrode (AuSPE), using cyclic voltammetry (CV) technique. The construction of the ANP sensor was carefully optimized to enhance its performance, including the film thickness and the procedures for effective template extraction from the MIP matrix. The MIP biosensor presented a linear response against polymeric NPs (PLGA-NPs@ANP) concentration logarithm ranging from 4.0 μg mL-1 to 100 μg mL-1, with a sensitivity of – 0.0129 mA mL μg-1 decade-1 and an LOD < 4.0 μg mL-1. Furthermore, the developed MIP receptor film was able to discriminate ANP-functionalized nanocarriers from non-functionalized NPs.