Paper Title
Fabrication of Nanoprobes for Selective Separation and Detection of Methicillin Resistantstaphylococcus Aureus

Abstract
The emergence of methicillin resistance in Staphylococcus aureus (MRSA) is one of the major issues affecting public health today. With a collection of virulence factors, MRSA is responsible for dreadful diseases such as pneumonia, sepsis, endocarditis, and osteomyelitis, with the ability to acquire resistance to most antibiotics. Conventional methods to identify MRSA strains are tedious and time-consuming, affecting the timely diagnosis of critical illness. Recently, nanoparticles-based biosensing probes working based on the principle of optical, electrochemical, and magnetic properties have been extensively used for the detection of pathogen. Quantum dots (QDs) and iron oxide magnetic nanoparticles (MGNPs) are the most commonly used nanoparticles in this context. Due to the broad absorption and narrow size-tunable emission spectra of QDs, it has been considered as a promising candidate for bioimaging applications. The superparamagnetic property and biocompatibility of MGNPs made it as a potential candidate for biomedical applications such as drug delivery, cellular therapy, and hyperthermia for cancer treatment. As a result, in this study, we have developed silica coated Fe3O4 MGNPs and core-shell CdTe/ZnS QDs for the selective magnetic separation and detection of MRSA from a mixed cultureusing spectrofluorometer. The carboxylate QDs and amine-functionalized MGNPs were synthesized using chemical reduction and solvothermal methods, respectively. The surface modification and amine functionalization of MGNPs were accomplished using sol-gel based co-condensation method. Simple carbodiimide chemistry has been carried out to conjugate Protein A on the surface of as-synthesized QDs and MGNPs to attach anti-PBP2a antibodies. The nanoparticles were characterized using a spectrofluorometer, dynamic light scattering spectroscopy (DLS), and Zeta potential. The developed nanoprobes will be optimized for sensitive and selective detection of MRSA.