Castor oil-based molecularly imprinted nanoparticles for the detection of cardiac troponin I: Towards green molecularly imprinted nanoreceptors

• Green molecularly imprinted polymer nanoparticles from castor-oil based monomer. • Nanoparticles with a uniform size distribution, low PDI and high stability. • Selective recognition of cardiac troponin I (cTnI) biomarker. • Sensitive cTnI detection directly in serum samples. • Scalable, eco-friendly MIP nanoparticles for biomedical applications. Molecularly imprinted polymers (MIPs) are synthetic materials that selectively recognize target molecules, offering cost-effective and stable alternatives to antibodies. While MIP nanoparticles are ideal for biomedical applications for their high surface area and their biomolecule-compatible size, traditional monomers used in their synthesis can pose issues in biocompatibility. This study presents a sustainable approach to MIP nanoparticle production using acrylated methyl ricinoleate (AMR), a functional monomer derived from castor oil. These "GreenNanoMIPs" were designed to recognize cardiac troponin I (cTnI), a key biomarker for cardiovascular events. The nanoparticles, with an average size of 81 nm, exhibited exceptional homogeneity in suspension, with a low PDI value of 0.064, and outstanding stability, as no changes in particle size distribution or PDI were observed even after one year. GreenNanoMIPs did recognize the entire cTnI protein thorough the epitope approach. Furthermore, GreenNanoMIPs were successfully used for the detection of the cTnI biomarker directly in serum. The study highlights the potential of eco-friendly, biocompatible MIPs for applications in diagnostics, drug delivery, and environmental sensing.