title: Simple approach for ultrasensitive electrochemical immunoassay of Clostridium difficile toxin B detection.
abstract: Clostridium difficile toxin B (Tcd B), as one of the primary contributing factors to the pathogenesis of C. difficile-associated diseases, has raised serious public concerns due to its virulence, spore-forming ability and persistence with major types of infectious diarrhea diseases, and been used as a potential biomarker in clinical diagnoses. Thus, a simple method for the determination of Tcd B was developed based on a sandwich-type electrochemical immunosensor. Greatly enhanced sensitivity was achieved based on fabricating the immunosensor by layer-by-layer coating carbon nanotubes (MWCNTs), Prussian blue (PB), Chitosan (CS), Glutaraldehyde (GA) composite on the working electrode as well as using graphene oxide (GO) as a nanocarrier in a multienzyme amplification strategy. In comparison with conventional methods, the proposed immunoassay exhibited high sensitivity and selectivity for the detection of Tcd B, providing a better linear response range from 0.003 to 320 ng/mL and a lower limit of detection (LOD) of 0.7 pg/mL (S/N=3) under optimal experimental conditions. The immunosensor exhibited convenience, low cost, rapidity, good specificity, acceptable stability and reproducibility. Moreover, satisfactory results were obtained for the determination of Tcd B in real human stool samples, indicating that the developed immunoassay has the potential to find application in clinical detection of Tcd B and other tumor markers as an alternative approach.
authors.affiliation: School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, People's Republic of China.
authors.forename: Yi-Shan
authors.initials: YS
authors.lastname: Fang
authors.forename: Shu-Yi
authors.initials: SY
authors.lastname: Chen
authors.forename: Xin-Jian
authors.initials: XJ
authors.lastname: Huang
authors.forename: Li-Shi
authors.initials: LS
authors.lastname: Wang
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Wang
authors.forename: Ju-Fang
authors.initials: JF
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification*; D001427:Bacterial Toxins / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000379:methods*; D048271:Chitosan / Q000737:chemistry; D016360:Clostridioides difficile / Q000302:isolation & purification* / Q000472:pathogenicity; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis* / Q000382:microbiology; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D037742:Nanotubes, Carbon; C031815:toxB protein, Clostridium difficile; D006046:Gold; D006108:Graphite; D048271:Chitosan
keywords: Chitosan; Clostridium difficile toxin B; Electrochemical immunosensor; Multiwalled carbon nanotubes; Prussian blue