The use of bimetallic nanoparticles for the simultabeous detection of proteins in a multicomponent solution by surface plasmon resonance

Abstract

This project aims at the sensibility enhancement of surface plasmon resonance with imaging (SPRi) in the detection of proteins in a multicomponent solution. The proposed method is based on the application of bimetallic nanoparticles (BMNPs) of platinum and gold (AuPtNPs) or gold and silver (AuAgNPs) previously functionalized with antibodies. The proteins to be detected by the SPRi technique will be Peanut agglutinin (PNA) and Concanavalin A (ConA). For comparative purposes, the assays will be also performed with monometallic gold NPs (AuNPs) since these NPs are currently the most used in order to enhance SPRi sensibility. Despite the extensive work on AuNPs, there is no information in the literature regarding the application of BMNPs for this application. Nevertheless, several works have shown the outstanding performance of BMNPs in catalysis and as antimicrobial agents. The researchers have assigned the behavior of BMNPs to their increased electronic oscillation in the nanometric structure which could also provide the enhanced ability to increase SPRi sensibility. Herein, the BMNPs will be functionalized with antibody anti-PNA and anti-ConA in solution and afterward, they will be incubated with solutions containing PNA and ConA at different concentrations. Then, the BMNPs containing the captured proteins will be injected into the SPRi system and the interaction between these NPs and the proteins immobilized on the biochip surface will be monitored by changes in the refractive index and by differential imaging. The interaction between BMNPs and the proteins will also be evaluated by UV-Vis spectroscopy by monitoring plasmon band shift from BMNPs as well as absorbance bands of proteins. It is expected to report at the end of this project a new method for the detection of proteins in multicomponent solutions at low concentrations.(AU)