title: Selective capturing and detection of Salmonella typhi on polycarbonate membrane using bioconjugated quantum dots.
abstract: Present work demonstrates the utilization of surface modified polycarbonate (PC) membrane as solid phase and antibody conjugated CdSe/ZnS quantum dots (QDs) as fluorescent label for the sensitive and selective detection of Salmonella typhi (S. typhi) in water in a period of 2.5h. PC membrane was surface modified with glycine and activated by EDC/NHS for immobilization of S. typhi specific IgG. Antibody immobilized porous PC membrane was incubated with bacteria contaminated water for immunocapturing of S. typhi. Antibody conjugated QDs were also prepared by using carbodiimide chemistry. Both modified PC membrane and quantum dots were characterized by using various modern analytical tools. It was estimated that 1.95 molecules of QDs were successfully bio-conjugated per unit of IgG. PC membrane with captured bacteria was incubated with prepared IgG conjugated QDs for the formation of sandwich complex. Analysis of the regions of interest (ROI) in fluorescent micrographs showed that newly developed method based on PC and fluorescent QDs has 100 times higher detection sensitivity (100 cells/mL) as compared with detection using conventional dye (FITC) based methods.
authors.affiliation: Centre for Biomedical Engineering, Indian Institute of Technology, Delhi 110016, India. richajackeray.iitd@gmail.com
authors.forename: Richa
authors.initials: R
authors.lastname: Jackeray
authors.forename: C K V Zainul
authors.initials: CK
authors.lastname: Abid
authors.forename: Gurpal
authors.initials: G
authors.lastname: Singh
authors.forename: Swati
authors.initials: S
authors.lastname: Jain
authors.forename: S
authors.initials: S
authors.lastname: Chattopadhyaya
authors.forename: Sameer
authors.initials: S
authors.lastname: Sapra
authors.forename: T G
authors.initials: TG
authors.lastname: Shrivastav
authors.forename: Harpal
authors.initials: H
authors.lastname: Singh
mesh_terms: D008567:Membranes, Artificial; D045663:Quantum Dots; D012485:Salmonella typhi / Q000302:isolation & purification*
chemical_list: D008567:Membranes, Artificial