title: Electrogenerated chemiluminescence biosensor incorporating ruthenium complex-labelled Concanavalin A as a probe for the detection of Escherichia coli.
abstract: A novel electrogenerated chemiluminescence (ECL) biosensor for highly sensitive detection of Escherichia coli (E. coli) was first developed by employing Concanavalin A (Con A) as a biological recognition element and bis(2,2'-bipyridine)-4'-methyl-4-carboxybipyridine ruthenium (II) (Ru1) complex as the detector. The ECL biosensor was fabricated by adsorbing carboxyl-functionalised single-wall carbon nanotubes (SWNTs) onto a paraffin-impregnated graphite electrode and further covalently coupling the Ru1-Con A probe onto the surface of the SWNT-modified electrode. Upon the binding of E. coli O157:H7 (as a model target), the biosensor showed a decreased ECL intensity in the presence of tri-n-propylamine (TPrA), which was in logarithmically direct proportion to the concentration of E. coli over a range from 5.0 × 10(2) to 5.0 × 10(5)cells/mL. The detection limit of this sensor was 127 cells/mL. Additionally, the ECL biosensor also showed satisfactory selectivity in discriminating gram-negative E. coli from gram-positive bacteria. The strategy developed in this study may be a promising approach and could be extended to the design of ECL biosensors for highly sensitive and rapid detection of other desired bacteria.
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China; Department of Chemistry, Yuncheng University, Yuncheng 044300, PR China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Yang
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Honglan
authors.initials: H
authors.lastname: Qi
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, PR China. Electronic address: cxzhang@snnu.edu.cn.
authors.forename: Chengxiao
authors.initials: C
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D002241:Carbohydrates / Q000032:analysis; D003208:Concanavalin A; D055664:Electrochemical Techniques; D004867:Equipment Design; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D006801:Humans; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D037742:Nanotubes, Carbon; D009942:Organometallic Compounds; D012428:Ruthenium; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D002241:Carbohydrates; D037742:Nanotubes, Carbon; D009942:Organometallic Compounds; C415768:tris(2,2'-bipyridyl)ruthenium(II); D003208:Concanavalin A; D012428:Ruthenium