Solid‐Phase Screening and Synthesis of Molecularly Imprinted Nanoparticles for Selective Recognition and Detection of Brain Natriuretic Peptide

Abstract A new recognition method is explored for the rapid detection of B‐type natriuretic peptide (BNP) based on the rational design and solid‐phase synthesis of molecularly imprinted nanoparticles (nanoMIP) encapsulated with carbon dots. The nanosized magnetic template is first prepared by attaching the epitope of BNP on amino‐functionalized magnetic carriers. High‐dilution polymerization of monomers in the presence of magnetic template generates lightly crosslinked imprinted nanoparticles. To obtain the optimal MIP formulation, a new combinatorial screening approach is developed by a competitive fluorescence assay using the magnetic template. The resultant nanoMIP exhibits high affinity and selectivity toward BNP with an equilibrium dissociation constant (KD) of ≈10−11 m. The proposed assay allows fast BNP detection within ≈7 min with a linear range of its concentration from 0.25 to 5000 pg mL−1 and a limit of detection of 0.208 pg mL−1 (S/N = 3). To demonstrate its practicability in clinical diagnosis, unknown real serum samples from 160 individuals are analyzed and the relative standard deviation is less than 4.43%. Compared with the routine electrochemiluminescence detection method that is widely used in hospital, the relative error is less than 4.98% and the correlation coefficient is 0.994.