Study On Early Detection Of Cancer Based On Molecularly Imprinted Nanoprobe And Surface Enhanced Raman

Separation and enrichment of molecularly imprinted polymers(MIP)prepared by molecular imprinting technique. Due to their outstanding characteristics e.g. chemical stability, simplicity of preparation, low cost, and rather high selectivity and affinity towards the template, the molecular imprinting technique have drawn attention in various fields. Surface enhanced Raman scattering(SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on substrates with rough surface or on nanostructures. Because of non-destructive, highly sensitive and selective,SERS has become a useful tool in bioanalytical science and it is mainly applied in detection and cell imaging. It has a good application prospect in the early detection of the disease, which is helpful to detect the target in the complex system. Our strategy is to design molecularly imprinted plasmonic nanosensor for selective SERS detection of protein biomarkers. Molecularly imprinted plasmonic nanosensor can selective capture and sensitive detection of protein biomarkers. This experiment have advantages of super sensitivity,no damage, and label-free. We achieved the detection of transferrin (TRF) and horseradish peroxidase (HRP) protein. This test methods avoid the traditional detection methods of complex, expensive, time-consuming and low sensitivity. It is of great significance in the early detection of cancer.This paper is divided into the following three parts:1. We synthesized gold nanorods with different aspect ratios and studied the effect of reactants on the properties of gold nanorods. The properties were characterized by TEM and UV. Molecularly imprinted plasmonic nanosensor has been prepared via the rational design of an ultrathin polymer layer on the surface of gold nanorods imprinted with the target protein. This nanosensor enabled selective fishing-out of the target protein biomarker even from a complex real sample such as human serum. Sensitive SERS detection of the protein biomarkers with a strong Raman enhancement was achieved by formation of protein imprinted gold nanorods aggregates, stacking of protein imprinted gold nanorods onto a glass plate, or self-assembly of protein imprinted gold nanorods into close-packed array. High specificity and sensitivity of this method were demonstrated with a detection limit of at least 10-8 mol/L for the target protein. This could provide a promising alternative for the currently used immunoassays and fluorescence detection, and offer an ultrasensitive, non-destructive, and label-free technique for clinical diagnosis applications.2. Thermosensitive molecularly imprinted plasmonic nanosensor was successfully synthesized for the selective recognition of the target protein on the surface of Au nanorod particles. The nanosensors with both temperature-sensitive and SERS were obtained via grafted the PNIPAAm-SH polymers on the Au nanorod in the presence of target protein. The PNIPAAm polymers were synthesized by the RAFT process. High specificity and sensitivity of this imprinted plasmonic nanosensor were demonstrated with a detection limit of at least 10-14 mol/L for the target protein.3. Thermosensitive molecularly imprinted plasmonic nanosensor can take live cell surface-enhanced Raman scattering (SERS) imaging in Ramansilent region. Finally, the SERS mapping in hela cell results confirmed that nanosensor exhibited outstanding SERS signal intensity in complex biological environment and excellent biocompatibility in live cells. Therefore, the thermosensitive molecularly imprinted plasmonic nanosensor has enormous potential of applications in biochemical monitoring, clinical diagnosis and medical theranostics in the future.