Functionalized polymeric magnetic nanoparticle assisted SERS immunosensor for the sensitive detection of S.  typhimurium.

Functionalized polymeric magnetic nanoparticle assisted SERS immunosensor for the sensitive detection of S. typhimurium. Anal Chim Acta. 2019 Aug 27;1067:98-106 Authors: Chattopadhyay S, Sabharwal PK, Jain S, Kaur A, Singh H Abstract The quest for detecting bacteria has gained momentum in food and beverage industry for preventing spoilage of products to maintain requisite quality. The present paper describes the development of a SERS immunosensor for the detection of model pathogen, S. typhimurium using strategically synthesized functionalized polymeric magnetic nanoparticles (FPMNPs) as effective capture probe and immunomagnetic separator. The synthesized probe contains surface diketonic functionalities which covalently link with amino groups of antibodies against Salmonella common structural antigen (CSA-1-Ab) and hence specifically captured the target bacteria. Magnetic core of nanoparticles facilitated easy separation of target bacteria from the milieu of non-specific molecules. Gold nanoparticles (GNPs) modified with CSA-1-Ab and external Raman reporter molecules (RRM) were used as signal probes. We compared the signalling attributes of 4-mercapto benzoic acid (MBA) and 5,5'-dithiobis(succinimidyl-2-nitrobenzoate) (DSNB) as RRMs. Capture and signal probes sandwich the target bacteria upon its addition, generating Raman signal from the 'hot-spots' created by signal probe. Under optimal conditions, the SERS intensities of MBA an...
Source: Analytica Chimica Acta - Category: Chemistry Authors: Tags: Anal Chim Acta Source Type: research